Difference between revisions of "Coelacanth" - New World Encyclopedia

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{{Taxobox
 
{{Taxobox
 
| name = Coelacanth
 
| name = Coelacanth
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| image = Coelacanth.png
 
| image = Coelacanth.png
 
| image_caption = ''[[Latimeria]] chalumnae''
 
| image_caption = ''[[Latimeria]] chalumnae''
| status = CR
 
| status_system = iucn3.1
 
 
| regnum = [[Animalia]]
 
| regnum = [[Animalia]]
 
| phylum = [[Chordate|Chordata]]
 
| phylum = [[Chordate|Chordata]]
 
| classis = [[Sarcopterygii]]
 
| classis = [[Sarcopterygii]]
| subclassis = '''Actinistia'''
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| subclassis = '''Coelacanthimorpha''' (Actinistia)
| infraclassis = '''Coelacanthimorpha'''
 
 
| ordo = '''Coelacanthiformes'''
 
| ordo = '''Coelacanthiformes'''
 
| ordo_authority = Berg, 1937
 
| ordo_authority = Berg, 1937
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See text.
 
See text.
 
}}
 
}}
'''Lungfish''' are [[Sarcopterygii|sarcopterygian]] [[fish]] of the [[taxon]] '''Dipnoi''', characterized by  
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'''Coelacanth''' is any [[Sarcopterygii|sarcopterygian]] [[fish]] of the subclass '''Coelacanthimorpha''' (Actinistia) and order '''Coelacanthiformes''', characterized by a three-lobed, diphycercal caudal fin, external nostrils, and an anterior dorsal fin in front of the center of the body (Nelson 2004). While coelacanths are well recognized in the [[fossil record]], there are only two living species, ''Latimeria chalumne'' and ''Latimeria menadoensis'' (Nelson 2006).  
 
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{{toc}}
The dipnoans are well represented in the [[fossil record]], but there are only six extant species, all freshwater species. The first living lungfish to be formally described was ''Lepidosiren paradoxa'', the South American lungfish, in 1837 (Nelson 2006).
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The coelacanths, which are related to [[lungfish]]es and [[tetrapod]]s, were believed to have been [[extinction|extinct]] since the end of the [[Cretaceous]] period, until the first ''Latimeria'' specimen ''(L. chalumne)'' was found off the east coast of [[South Africa]] in 1938. It would be 14 years before a second specimen was captured and another 45 years before another species was identified. The discovery of fish known only from the fossil record has been an exciting story of discovery, propelling an otherwise very rare fish to the forefront of popularity.
 
 
 
 
'''Coelacanth''' ({{pronEng|ˈsiːləkænθ}}, adaptation of Modern Latin ''Cœlacanthus'' > cœl-us + acanth-us from [[Ancient Greek|Greek]] κοῖλ-ος [hollow] + ἄκανθ-α [spine]) is the common name for an [[Order (biology)|order]] of [[fish]] that includes the oldest living [[Lineage (evolution)|lineage]] of [[gnathostomata]] known to date.  The coelacanths, which are related to [[lungfish]]es and [[tetrapod]]s, were believed to have been [[extinction|extinct]] since the end of the [[Cretaceous]] period, until the first ''Latimeria'' specimen was found off the east coast of [[South Africa]], off the [[Chalumna River]] in [[1938]]. (They are, therefore, a [[Lazarus taxon]].)  Since 1938, ''Latimeria chalumnae'' have been found in the [[Comoros]], [[Kenya]], [[Tanzania]], [[Mozambique]], [[Madagascar]], and in [[Greater St. Lucia Wetland Park]] in [[South Africa]]. The second species, ''L. menadoensis'', was described from [[Sulawesi]], [[Indonesia]] in 1999.<ref>[http://www.pnas.org/cgi/content/abstract/96/22/12616 Reference for divergence dated on mitochondrial genome]</ref><ref>{{cite journal  | last = Erdmann  | first = Mark V.  | authorlink =  | coauthors =  | title = An Account of the First Living Coelacanth known to Scientists from Indonesian Waters  | journal = Environmental Biology of Fishes  | volume = Volume 54  | issue = #4  | pages = 439–443  | publisher = Springer Netherlands  | date = April 1999  | url = http://www.springerlink.com/content/u5143r02v5u7133j/  | doi = 10.1023/A:1007584227315  | id = 0378-1909 (Print) 1573-5133 (Online) | accessdate = 2007-05-18}}</ref>
 
  
 
==Overview and description==
 
==Overview and description==
Lungfish together with [[coelacanth]]s comprise the vertebrate class [[Sarcopterygii]]. The bony fish representatives of this class, known as lobe-finned fish, are characterized by lobed paired fins, which are joined to the body by a single bone (Clack 2002). Sarcopterygians also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of actinopterygians (ray-finned fishes). The braincase of sarcoptergygians primitively has a hinge line, but this is lost in tetrapods and lungfish. Many early sarcopts have a symmetrical tail.
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Coelacanths, together with lungfish, are part of the [[vertebrate]] class [[Sarcopterygii]]. The bony fish representatives of this class, known as lobe-finned fish, are characterized by lobed paired fins, which are joined to the body by a single bone (Clack 2002). Sarcopterygians also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of actinopterygians (ray-finned fishes). The braincase of sarcoptergygians primitively has a hinge line, but this is lost in tetrapods and lungfish. Many early sarcoptergians have a symmetrical tail. Some taxonomists also include the tetrapods ([[amphibian]]s, [[reptile]]s, [[bird]]s, [[mammal]]s) in Sacropterygii in order to make this a monophyletic group (Nelson 2006).  
 
 
Coelacanths (order Coelacanthiformes), living and extinct, are characterized by a caudal fin with three lobes, external nostrils, and an anterior dorsal fin in front of the center of the body (Nelson 2004). There are two living species, Latimeria chalumne and L. menadoensis (Nelson 2006). The first living species ever found, Latimeria chalumnae, is a marine species known from South Africa, Comoros Archipelago, and the Mozambique area (Nelson 2006). It was first found off of South Africa in 1938. Adults reach 1.8 meters and it has an unusual method of swimming in keeping its body rigid (Nelson 2006). It is the only living chordate with an intracranial joint, although this feature appears in other coelacanths (Nelson 2006).
 
  
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The coelacanths are placed in the subclass Coelacanthimorpha, while the lungfish traditionally are placed in the subclass Dipnoi, although Nelson (2006) designates Dipnotetrapodomorpha as the subclass with lungfish,
  
Some taxonomists also include the tetrapods (amphibians, reptiles, birds, mammals) in Sacropterygii in order to make this a monophyletic group (Nelson 2006).  
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Coelacanthimorpha includes one order, Coelacanthiformes. Within Coelacanthiformes, Nelson (2006) recognizes nine families, of which eight include only fossil members and one includes two living species of coelacanth as well as fossil members. Coelacanths (order Coelacanthiformes), living and extinct, are characterized by a diphycercal caudal fin (having a tail fin with the vertebral column extending to the tip, with symmetrical lower and upper parts), and an anterior dorsal fin in front of the center of the body (Nelson 2004). Coelacanths are [[lobe-finned fish]] with the [[pectoral fin|pectoral]] and [[anal fin]]s on fleshy stalks supported by bones, and the tail or [[caudal fin]] is divided into three lobes, the middle one of which also includes a continuation of the [[notochord]]. Coelacanths have modified [[Scale (zoology)#Cosmoid scales|cosmoid scales]], which are thinner than true cosmoid scales, which can only be found on extinct fish. Extant coelacanths also have a special electroreceptive device called a [[rostral organ]] in the front of the skull, which probably helps in prey detection. The small device also could help the balance of the fish, as echolocation could be a factor in the way this fish moves.  
  
The lungfish traditionally are placed in the subclass Dipnoi, while the coelacanths are placed in the subclass Coelacanthimorpha. However, Nelson (2006), in his book ''Fishes of the World'', while recognizing Coelacanthimorpha, designates Dipnotetrapodomorpha as the subclass with lungfish,
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Coelacanth ({{pronEng|ˈsiːləkænθ}}) is an adaptation of Modern Latin ''Cœlacanthus'' > cœl-us + acanth-us from [[Ancient Greek|Greek]] κοῖλ-ος [hollow] + ἄκανθ-α [spine]). This is an order of [[fish]] that includes the oldest living [[Lineage (evolution)|lineage]] of [[gnathostomata]] known to date.
  
Coelacanths are [[lobe-finned fish]] with the [[pectoral fin|pectoral]] and [[anal fin]]s on fleshy stalks supported by bones, and the tail or [[caudal fin]] [[Fish anatomy#Types of fins|diphycercal]] (divided into three lobes), the middle one of which also includes a continuation of the [[notochord]]. Coelacanths have modified [[Scale (zoology)#Cosmoid scales|cosmoid scales]], which are thinner than true cosmoid scales, which can only be found on extinct fish. Coelacanths also have a special electroreceptive device called a [[rostral organ]] in the front of the skull, which probably helps in prey detection. The small device also could help the balance of the fish, as echolocation could be a factor in the way this fish moves.
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===Living species===
  
===Extant species===
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There are two living species of coelacanths, ''Latimeria chalumne'' and ''L. menadoensis'' (Nelson 2006). These are placed in the family Latimeriidae. The first living species ever found, ''Latimeria chalumnae,'' is a marine species. It was first found off of South Africa in 1938. Since 1938, ''Latimeria chalumnae'' have been found in the [[Comoros]], [[Kenya]], [[Tanzania]], [[Mozambique]], [[Madagascar]], and in [[Greater St. Lucia Wetland Park]] in [[South Africa]]. Adults reach 1.8 meters and it has an unusual method of swimming in keeping its body rigid (Nelson 2006). It is the only living chordate with an intracranial joint, although this feature appears in other coelacanths (Nelson 2006). It is live-bearing.
  
The six extant species of lungfishes ar
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The second species, ''L. menadoensis,'' was described by Pouyaud et al. in 1999, after first being sighted in an Indonesian fish market in 1997 and the preservation of a second specimen in 1998 (Nelson 2006; Erdmann 1999). Erdmann (1999) documented these events in a 1999 issue of ''Environmental Biology of Fishes.''
  
==Fossil record==
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===Fossil record===
They first appear in the [[Fossil|fossil record]] in the Middle [[Devonian]], about 410 million years ago.<ref>A fossil coelacanth jaw found in a stratum datable 410 [[mya (unit)|mya]] that was collected near Buchan in [[Victoria, Australia|Victoria]], [[Australia]]'s  East Gippsland, currently holds the record for oldest coelacanth; it was given the name ''Eoactinistia foreyi'' when it was published in September 2006. [http://www.int.iol.co.za/index.php?set_id=1&click_id=31&art_id=qw1156833901231B223]</ref> Prehistoric species of coelacanth lived in many [[Body of water|bodies of water]] in Late [[Paleozoic]] and [[Mesozoic]] times.  
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Coelacanths first appear in the [[Fossil|fossil record]] in the Middle [[Devonian]], about 410 million years ago. A fossil coelacanth jaw found in a stratum datable 410 [[mya (unit)|mya]] that was collected near Buchan in [[Victoria, Australia|Victoria]], [[Australia]]'s  East Gippsland, currently holds the record for oldest coelacanth; it was given the name ''Eoactinistia foreyi'' when it was published in September 2006 (Burgess 2006). Prehistoric species of coelacanth lived in many [[Body of water|bodies of water]] in Late [[Paleozoic]] and [[Mesozoic]] times.  
  
Although now represented by only two known living [[species]], as a group the coelacanths were once very successful with many genera and species that left an abundant fossil record from the [[Devonian]] to the end of the [[Cretaceous]] period, at which point they apparently suffered a nearly complete extinction. No fossils dated after this point are known to have been found.{{Fact|date=July 2007}} It is often claimed that the coelacanth has remained unchanged for millions of years, but, in fact, the living species and even genus are unknown from the fossil record. However, some of the [[extinct species]], particularly those of the last known fossil coelacanth, the Cretaceous genus ''[[Macropoma]]'', closely resemble the living species.{{Fact|date=July 2007}} The most likely reason for the gap is the taxon having become extinct in shallow waters.  Deep-water fossils are only rarely lifted to levels where paleontologists can recover them, making most deep-water taxa disappear from the [[fossil]] record.  This situation is still under investigation by scientists.
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Although now represented by only two known living [[species]], as a group the coelacanths were once very successful with many genera and species that left an abundant fossil record from the [[Devonian]] to the end of the [[Cretaceous]] period, at which point they apparently suffered a nearly complete [[extinction]]. It is often claimed that the coelacanth has remained unchanged for millions of years, but, in fact, the living species and even genus are unknown from the fossil record. However, some of the [[extinct species]], particularly those of the last known fossil coelacanth, the Cretaceous genus ''[[Macropoma]],'' closely resemble the living species.  
  
==''Latimeria'' - the modern Coelacanth==
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==''Latimeria,'' the modern coelacanth==
 
{{Taxobox
 
{{Taxobox
 
| name = Modern Coelacanths
 
| name = Modern Coelacanths
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| image = Latimeria chalumnae01.jpg
 
| image = Latimeria chalumnae01.jpg
 
| image_caption = ''Latimeria chalumnae''
 
| image_caption = ''Latimeria chalumnae''
| regnum = [[Animalia]]
 
| phylum = [[Chordate|Chordata]]
 
| classis = [[Sarcopterygii]]
 
| subclassis = [[Coelacanthimorpha]]
 
 
| ordo = [[Coelacanthiformes]]
 
| ordo = [[Coelacanthiformes]]
 
| familia =[[Latimeriidae]]
 
| familia =[[Latimeriidae]]
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| subdivision =  
 
| subdivision =  
 
* ''L. chalumnae'' <small>([[Type (zoology)|type]])</small>
 
* ''L. chalumnae'' <small>([[Type (zoology)|type]])</small>
* ''L. menadoensis'' <small>Pouyaud ''et al.'', 1999</small>
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* ''L. menadoensis'' <small>Pouyaud et al., 1999</small>
 
}}
 
}}
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The average weight of the living West Indian Ocean coelacanth, ''Latimeria chalumnae,'' is 80 kilograms (176 pounds), and they can reach up to 2 meters (6.5 feet) in length. Adult females are slightly larger than males. Based on growth rings in their ear bones ([[otoliths]]), scientists infer that individual coelacanths may live as long as 80 to 100 years. Coelacanths live as deep as 700 meters (2300 feet) below [[sea level]], but are more usually found at depths of 90 to 200 meters. Living examples of ''Latimeria chalumnae'' have a deep blue color, which probably [[camouflage|camouflages]] them from prey species; however, the Indonesian species is brown. ''Latimeria chalumnae'' is widely but very sparsely distributed around the rim of the western [[Indian Ocean]], from South Africa northward along the east African coast to Kenya, the [[Comoro Island]] and [[Madagascar]], seemingly occurring in small colonies.
  
===Biological characteristics===
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Coelacanth eyes are very sensitive, and have a ''[[tapetum lucidum]].'' Coelacanths are almost never caught in the daytime or on nights with full moons, due to the sensitivity of their eyes. Coelacanth eyes also have many [[rod cell|rods]]: receptors in the retina that help animals see in dim light. Together, the rods and tapetum help the fish see better in dark water.  
The average weight of the living West Indian Ocean coelacanth, ''Latimeria chalumnae'', is 80 [[Kilogram|kg]] (176 lb), and they can reach up to 2 [[Metre|m]] (6.5 ft) in length. Adult females are slightly larger than males. Based on growth rings in their ear bones ([[otoliths]]), scientists infer that individual coelacanths may live as long as 80 to 100 years. Coelacanths live as deep as 700 m (2300 ft) below [[sea level]], but are more usually found at depths of 90 to 200 m.  Living examples of ''Latimeria chalumnae'' have a deep blue color which probably camouflages them from prey species; however, the Indonesian species is brown. ''Latimeria chalumnae'' is widely but very sparsely distributed around the rim of the western [[Indian Ocean]], from South Africa northward along the east African coast to Kenya, the Comoro Island and Madagascar, seemingly occurring in small colonies.
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[[Image:Coelacanth1.jpg|thumb|left|250px|Coelacanth model in the [[Oxford University Museum of Natural History]]]]
Coelacanth eyes are very sensitive, and have a ''[[tapetum lucidum]]''. Coelacanths are almost never caught in the daytime or on nights with full moons, due to the sensitivity of their eyes. Coelacanth eyes also have many [[rod cell|rods]]: receptors in the retina that help animals see in dim light. Together, the rods and [[tapetum lucidum|tapetum]] help the fish see better in dark water.  
 
[[Image:Coelacanth1.JPG|thumb|left|250px|Coelacanth model in the [[Oxford University Museum of Natural History]]]]
 
  
Coelacanths are opportunistic feeders, hunting [[cuttlefish]], [[squid]], [[snipe eel]]s, small [[shark]]s, and other fish found in their deep reef and volcanic slope [[Habitat (ecology)|habitat]]s. Coelacanths are also known to swim head down, backwards or belly up to locate their prey, presumably utilizing their [[Rostral organ|rostral gland]]. Scientists suspect that one reason this fish has been so successful is that specimens are able to slow down their [[metabolism]]s at will, sinking into the less-inhabited depths and minimizing their nutritional requirements in a sort of [[hibernation]] mode.
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Coelacanths are opportunistic feeders, hunting [[cuttlefish]], [[squid]], [[snipe eel]]s, small [[shark]]s, and other fish found in their deep reef and volcanic slope [[Habitat (ecology)|habitat]]s. Coelacanths are also known to swim head down, backwards, or belly up to locate their prey, presumably utilizing their [[Rostral organ|rostral gland]]. Scientists suspect that one reason this fish has been so successful is that specimens are able to slow down their [[metabolism]]s at will, sinking into the less-inhabited depths and minimizing their nutritional requirements in a sort of [[hibernation]] mode.
  
The coelacanths which live near [[Sodwana Bay]], [[South Africa]], rest in caves at depths of 90 to 150 m during daylight hours, but disperse and swim to depths as shallow as 55 m when hunting at night. The depth is not as important as their need for very dim light and, more importantly, for water which has a temperature of 14 to 22 °C. They will rise or sink to find these conditions. The amount of oxygen that their blood can absorb from the water through the gills is dependent on water temperature. Scientific research suggests that the coelacanth must stay in cold, well-oxygenated water or else their blood cannot absorb enough oxygen. <ref> page 200, Weinberg, Samantha. 2006. A Fish Caught in Time: the Search for the Coelacanth. HarperCollins Publishers, New York, NY.</ref>
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The coelacanths that live near [[Sodwana Bay]], [[South Africa]] rest in caves at depths of 90 to 150 meters during daylight hours, but disperse and swim to depths as shallow as 55 meters when hunting at night. The depth is not as important as their need for very dim light and, more importantly, for water which has a temperature of 14 to 22°C. They will rise or sink to find these conditions. The amount of oxygen that their blood can absorb from the water through the gills is dependent on water temperature. Scientific research suggests that the coelacanth must stay in cold, well-oxygenated water or else their blood cannot absorb enough [[oxygen]] (Weinberg 2000).
  
In accordance with the [[CITES|Convention on International Trade of Endangered Species]] treaty, the coelacanth was added to Appendix I (threatened with extinction) in 1989. The treaty forbids international trade for commercial purposes and regulates all trade, including sending specimens to museums, through a system of permits. In 1998, the total coelacanth population was estimated to have been 500 or fewer, a number that would threaten the survival of the species.<ref name="washingtonpost1">Jewett, Susan L., [http://www.washingtonpost.com/wp-srv/national/horizon/nov98/fishstory.htm "On the Trail of the Coelacanth, a Living Fossil"], ''[[The Washington Post]]'', [[1998-11-11]], Retrieved on [[2007-06-19]].</ref>
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In accordance with the [[CITES|Convention on International Trade of Endangered Species]] treaty, the coelacanth was added to Appendix I (threatened with extinction) in 1989. The treaty forbids international trade for commercial purposes and regulates all trade, including sending specimens to museums, through a system of permits. In 1998, the total coelacanth population was estimated to have been 500 or fewer, a number that would threaten the survival of the species (Jewett 1998).
  
===Reproduction===
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Female coelacanths [[ovoviviparity|give birth to live young]], called "pups," in groups of between 5 and 25 [[spawn (biology)#Fry|fry]] at a time; the pups are capable of surviving on their own immediately after birth. Their reproductive behaviors are not well known, but it is believed that they are not [[Sexual maturity|sexually mature]] until after 20 years of age. Gestation time is 13 months.
Female coelacanths [[ovoviviparity|give birth to live young]], called "pups", in groups of between 5 and 25 [[spawn (biology)#Fry|fry]] at a time; the pups are capable of surviving on their own immediately after birth. Their reproductive behaviors are not well known, but it is believed that they are not [[Sexual maturity|sexually mature]] until after 20 years of age. Gestation time is 13 months.
 
  
==Discoveries==
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==History of discoveries==
  
 
{| class="wikitable"
 
{| class="wikitable"
|+ '''Timeline of discoveries'''<ref>Iziko South African Museum, Cape Town</ref><ref name="Nelson">Nelson, Joseph S. (2006). ''Fishes of the World''. [[John Wiley & Sons]], Inc. ISBN 0471250317</ref>
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|+ '''Timeline of discoveries'''<ref>Iziko South African Museum, Cape Town</ref><ref name="Nelson">J. Nelson. ''Fishes of the World,'' 4th edition (Hoboken, NJ: John Wiley & Sons, 2006). ISBN 0471250317.</ref>
 
! Date || Description
 
! Date || Description
 
|-
 
|-
| '''1938''' || ([[December 23]]) Discovery of the first modern coelacanth 30&nbsp;[[kilometer]]s SW of [[East London, South Africa]].
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| '''1938''' || (December 23) Discovery of the first modern coelacanth 30&nbsp;[[kilometer]]s SW of [[East London, South Africa]].
 
|-
 
|-
| '''1952''' || ([[December 21]]) Second specimen identified in the [[Comoros]]. Since then more than 200 have been caught around the islands.
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| '''1952''' || (December 21) Second specimen identified in the [[Comoros]]. Since then more than 200 have been caught around the islands.
 
|-
 
|-
 
| '''1988''' || First photographs of coelacanths in their natural habitat, by Hans Fricke off [[Grande Comore]].
 
| '''1988''' || First photographs of coelacanths in their natural habitat, by Hans Fricke off [[Grande Comore]].
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| '''1995''' || First recorded coelacanth on [[Madagascar]], 30&nbsp;kilometers S of [[Toliara|Tuléar]].
 
| '''1995''' || First recorded coelacanth on [[Madagascar]], 30&nbsp;kilometers S of [[Toliara|Tuléar]].
 
|-
 
|-
| '''1997''' || ([[September 18]]) New species of coelacanth found in [[Indonesia]].
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| '''1997''' || (September 18) New species of coelacanth found in [[Indonesia]].
 
|-
 
|-
 
| '''2000''' || A group found by divers off [[Sodwana Bay]], [[South Africa]].
 
| '''2000''' || A group found by divers off [[Sodwana Bay]], [[South Africa]].
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| '''2003''' || First coelacanth caught by fisherman in [[Tanzania]]. Within the year, 22 were caught in total.
 
| '''2003''' || First coelacanth caught by fisherman in [[Tanzania]]. Within the year, 22 were caught in total.
 
|-
 
|-
| '''2004''' || Canadian researcher William Sommers captured the largest recorded specimen of coelacanth off the coast of [[Madagascar]].{{Fact|date=October 2007}}
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| '''2004''' || Canadian researcher William Sommers captured the largest recorded specimen of coelacanth off the coast of [[Madagascar]].
 
|-
 
|-
| '''2007''' || ([[May 19]]) [[Indonesia]]n fisherman Justinus Lahama caught a 1.31&nbsp;[[metre|meter]] (4.30&nbsp;[[foot (unit of length)|ft]]) long, 51&nbsp;[[kilogram]] (112&nbsp;[[pound (mass)|lb]]) coelacanth off [[Sulawesi|Sulawesi Island]], near Bunaken National Marine Park, that survived for 17 hours in a quarantined pool.<ref name="CNN1">[[Reuters]] (2007), [http://today.reuters.co.uk/news/articlenews.aspx?type=oddlyEnoughNews&storyid=2007-05-21T055304Z_01_JAK147591_RTRIDST_0_OUKOE-UK-INDONESIA-FISH.XML "Indonesian fisherman nets ancient fish"], ''Reuters UK'', [[2007-05-21]], Retrieved on [[2007-07-16]].</ref>
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| '''2007''' || (May 19) [[Indonesia]]n fisherman Justinus Lahama caught a 1.31-meter-long (4.30-foot-long), 51-kilogram (112-pound) coelacanth off [[Sulawesi|Sulawesi Island]], near Bunaken National Marine Park, that survived for 17 hours in a quarantined pool.  
 
|-
 
|-
| '''2007''' || ([[July 15]]) Two fishermen from [[Zanzibar]] caught a coelacanth measuring 1.34&nbsp;meters (4.40&nbsp;ft), and weighing 27&nbsp;kilograms (60&nbsp;lb). The fish was caught off the north tip of the island, off the coast of Tanzania.<ref>Reuters (2007), [http://news.yahoo.com/s/nm/20070715/sc_nm/zanzibar_fish_dc "Zanzibar fishermen land ancient fish"],''[[yahoo.com]]'', [[2007-07-15]], Retrieved on [[2007-07-16]].</ref>
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| '''2007''' || (July 15) Two fishermen from [[Zanzibar]] caught a coelacanth measuring 1.34 meters (4.40 feet), and weighing 27 kilograms (60 pounds). The fish was caught off the north tip of the island, off the coast of Tanzania.  
 
|-
 
|-
 
|}
 
|}
 
===First find in South Africa===
 
===First find in South Africa===
[[Image:Coelacanth and Courtenay-Latimer.jpg|left|thumb|250px|[[Marjorie Courtenay-Latimer]] with the first discovered Coelacanth.]]
 
  
On [[December 23]], [[1938]], Hendrik Goosen, the captain of the [[Commercial trawler|trawler]] ''Nerine'', returned to the harbour at [[East London, South Africa]], after a trawl around the mouth of the [[Chalumna River]]. As he frequently did, he telephoned his friend, [[Marjorie Courtenay-Latimer]], curator at East London's small museum, to see if she wanted to look over the contents of the catch for anything interesting. At the harbour, Latimer noticed a blue fin and took a closer look. There she found what she later described as "the most beautiful fish I had ever seen, five feet long, and a pale [[mauve]] blue with [[iridescent]] silver markings."  
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On December 23, 1938, Hendrik Goosen, the captain of the [[Commercial trawler|trawler]] ''Nerine,'' returned to the harbor at [[East London, South Africa]], after a trawl around the mouth of the [[Chalumna River]]. As he frequently did, he telephoned his friend, [[Marjorie Courtenay-Latimer]], curator at East London's small museum, to see if she wanted to look over the contents of the catch for anything interesting. At the harbor, Latimer noticed a blue fin and took a closer look. There she found what she later described as "the most beautiful fish I had ever seen, five feet long, and a pale [[mauve]] blue with [[iridescent]] silver markings."  
  
Failing to find a description of the creature in any of her books, she attempted to contact her friend, Professor [[James Leonard Brierley Smith]], but he was away for Christmas. Unable to preserve the fish, she reluctantly sent it to a [[taxidermy|taxidermist]]. When Smith returned, he immediately recognized it as a coelacanth, known only from fossils. Smith named the fish ''Latimeria chalumnae'' in honor of Marjorie Courtenay-Latimer and the waters in which it was found. The two discoverers received immediate recognition, and the fish became known as a "[[living fossil]]." The 1938 coelacanth is still on display in the [[East London, South Africa]], museum.
+
Failing to find a description of the creature in any of her books, she attempted to contact her friend, Professor [[James Leonard Brierley Smith]], but he was away for Christmas. Unable to preserve the fish, she reluctantly sent it to a [[taxidermy|taxidermist]]. When Smith returned, he immediately recognized it as a coelacanth, the group known previously only from [[fossil]]s. Smith named the fish ''Latimeria chalumnae'' in honor of Marjorie Courtenay-Latimer and the waters in which it was found. The two discoverers received immediate recognition, and the fish became known as a "[[living fossil]]." The 1938 coelacanth is still on display in the [[East London, South Africa]], museum.
  
However, as the specimen had been stuffed, the [[gill]]s and [[skeleton]] were not available for examination, and some doubt therefore remained as to whether it was truly the same species. Smith began a hunt for a second specimen that would take more than a decade.
+
However, as the specimen had been stuffed, the [[gill]]s and [[skeleton]] were not available for examination, and some doubt therefore remained as to its identity. Smith began a hunt for a second specimen that would take more than a decade.
  
 
===Comoros===
 
===Comoros===
 
[[Image:Latimeria Chalumnae - Coelacanth - NHMW.jpg|right|thumb|300px|Preserved specimen of ''Latimeria chalumnae'' in the [[Naturhistorisches Museum|Natural History Museum]], Vienna, Austria (length: 170 cm - weight: 60 kg). This specimen was caught on 18 October 1974, next to Salimani/Selimani (Grande Comore, Comoros Islands) {{Coor dms|11|48|40.7|S|43|16|3.3|E}}.]]
 
[[Image:Latimeria Chalumnae - Coelacanth - NHMW.jpg|right|thumb|300px|Preserved specimen of ''Latimeria chalumnae'' in the [[Naturhistorisches Museum|Natural History Museum]], Vienna, Austria (length: 170 cm - weight: 60 kg). This specimen was caught on 18 October 1974, next to Salimani/Selimani (Grande Comore, Comoros Islands) {{Coor dms|11|48|40.7|S|43|16|3.3|E}}.]]
  
A worldwide search was launched for more coelacanths, with a reward of 100 [[Pound sterling|British pounds]], a very substantial sum to the average South African fisherman of the time. Fourteen years later, one specimen was found in the [[Comoros]], but the fish was no stranger to the locals in the port of Mutsamudu on the Comorian island of [[Anjouan]], the Comorians were puzzled to be so rewarded for a "gombessa" or "mame", their names for the nearly inedible fish that their fishermen occasionally caught by mistake.
+
A worldwide search was launched for more coelacanths, with a reward of 100 [[Pound sterling|British pounds]], a very substantial sum to the average South African fisherman of the time. Fourteen years later, one specimen was found in the [[Comoros]], but the fish was no stranger to the locals&mdash;in the port of Mutsamudu on the Comorian island of [[Anjouan]], the Comorians were puzzled to be so rewarded for a "gombessa" or "mame," their names for the nearly inedible fish that their fishermen occasionally caught by mistake.
  
The second specimen, found in 1952 by Comorian fisherman Ahamadi Abdallah, was described as a different species, first as 'Malania hunti' and later as ''Malania anjounae'', after [[Daniel François Malan]], the [[South African Prime Minister]] who had dispatched an [[SAAF]] [[C-47 Skytrain|Dakota]] at the behest of Professor Smith to fetch the specimen. It was later discovered that the lack of a first [[dorsal fin]], at first thought to be significant, was caused by an injury early in the specimen's life. Ironically, Malan was a staunch [[creationism|creationist]]; when he was first shown the primitive creature, he exclaimed, with a twinkle, "My, it is ugly. Do you mean to say we once looked like that?"<ref> page 73, Weinberg, Samantha. 2006. A Fish Caught in Time: the Search for the Coelacanth. HarperCollins Publishers, New York, NY.</ref> The specimen retrieved by Smith is on display at the [[SAIAB]] in [[Grahamstown]], [[South Africa]] where he worked.
+
The second specimen, found in 1952 by Comorian fisherman Ahamadi Abdallah, was described as a different species, first as ''Malania hunti'' and later as ''Malania anjounae,'' after [[Daniel François Malan]], the [[South African Prime Minister]] who had dispatched an [[SAAF]] [[C-47 Skytrain|Dakota]] at the behest of Professor Smith to fetch the specimen. It was later discovered that the lack of a first [[dorsal fin]], at first thought to be significant, was caused by an injury early in the specimen's life. Ironically, Malan was a staunch [[creationism|creationist]]; when he was first shown the primitive creature, he exclaimed, with a twinkle, "My, it is ugly. Do you mean to say we once looked like that?" (Weinberg 2000). The specimen retrieved by Smith is on display at the [[SAIAB]] in [[Grahamstown]], [[South Africa]] where he worked.
  
The Comorians are now aware of the significance of the [[endangered species]], and have established a program to return accidentally-caught coelacanth to deep water.
+
The Comorians are now aware of the significance of the [[endangered species]] and have established a program to return any accidentally-caught coelacanth to deep water.
  
As for Smith, who died in 1968, his account of the coelacanth story appeared in the book ''Old Fourlegs'', first published in 1956. His book ''Sea Fishes of the Indian Ocean'', illustrated and co-authored by his wife Margaret, remains the standard [[Ichthyology|ichthyological]] reference for the region.
+
As for Smith, who died in 1968, his account of the coelacanth story appeared in the book ''Old Fourlegs,'' first published in 1956. His book ''Sea Fishes of the Indian Ocean,'' illustrated and co-authored by his wife Margaret, remains the standard [[Ichthyology|ichthyological]] reference for the region.
  
In [[1988]], [[National Geographic]] photographer [[Hans Fricke]] was the first to photograph the species in its natural habitat, {{convert|180|m|ft|-1}} off [[Grande Comore]]'s west coast.<ref name="NatlGeo">{{cite journal|last=Fricke|first=Hans|title=Coelacanths:The fish that time forgot|journal=[[National Geographic]]|pages=824–828|volume=173|issue=6|date=June, [[1988]]|doi=10.1023/A:1007584227315}}</ref>
+
In 1988, [[National Geographic]] photographer [[Hans Fricke]] was the first to photograph the species in its natural habitat, 180 meters (590 feet) off [[Grande Comore]]'s west coast (Fricke 1988).
  
 
===Second species in Indonesia===
 
===Second species in Indonesia===
On [[September 18]], [[1997]], Arnaz and Mark Erdmann, traveling in [[Indonesia]] on their [[honeymoon]], saw a strange fish enter the market at [[Manado Tua]], on the island of [[Sulawesi]].<ref name="washingtonpost1"/> Mark thought it was a ''gombessa'' (Comoros coelacanth), although it was brown, not blue. An expert noticed their pictures on the [[Internet]] and realized its significance. Subsequently, the Erdmanns contacted local fishermen and asked for any future catches of the fish to be brought to them. A second Indonesian specimen, 1.2 m in length and weighing 29 kg., was captured alive on [[July 30]], [[1998]].<ref name="Nelson"/> It lived for six hours, allowing scientists to photographically document its coloration, fin movements and general behavior. The specimen was preserved and donated to the ''Museum Zoologicum [[Bogor]]iense (MZB)'', part of the ''[[Indonesian Institute of Sciences]] (LIPI)''.<ref name="washingtonpost1"/>
+
On September 18, 1997, Arnaz and Mark Erdmann, traveling in [[Indonesia]] on their [[honeymoon]], saw a strange fish enter the market at [[Manado Tua]], on the island of [[Sulawesi]] (Jewett 1998). Mark thought it was a ''gombessa'' (Comoros coelacanth), although it was brown, not blue. An expert noticed their pictures on the [[Internet]] and realized its significance. Subsequently, the Erdmanns contacted local fishermen and asked for any future catches of the fish to be brought to them. A second Indonesian specimen, 1.2 meters in length and weighing 29 kilograms was captured alive on July 30, 1998 (Nelson 2006). It lived for six hours, allowing scientists to photographically document its coloration, fin movements, and general behavior. The specimen was preserved and donated to the ''Museum Zoologicum [[Bogor]]iense (MZB),'' part of the ''[[Indonesian Institute of Sciences]] (LIPI)'' (Jewett 1998).
  
[[DNA]] testing revealed that this specimen differed genetically from the Comorian population. Superficially, the Indonesian coelacanth, locally called ''raja laut'' ("King of the Sea"), appears to be the same as those found in the Comoros except that the background coloration of the skin is brownish-gray rather than bluish. This fish was described in a 1999 issue of ''Environmental Biology of Fishes'' by Pouyaud et al. It was given the [[Binomial nomenclature|scientific name]] ''Latimeria menadoensis''. A molecular study estimated the divergence time between the two coelacanth species to be 40–30 [[mya (unit)|mya]].<ref>Inoue J.G., Miya M., Venkatesh B., Nishida M. 2005. The mitochondrial genome of Indonesian coelacanth Latimeria menadoensis (Sarcopterygii: Coelacanthiformes) and divergence time estimation between the two coelacanths. Gene 349: 227-235</ref>
+
[[DNA]] testing revealed that this specimen differed genetically from the Comorian population. Superficially, the Indonesian coelacanth, locally called ''raja laut'' ("King of the Sea"), appears to be the same as those found in the Comoros except that the background coloration of the skin is brownish-gray rather than bluish. This fish was described in by Pouyard et al. in 1999. It was given the [[Binomial nomenclature|scientific name]] ''Latimeria menadoensis.'' A molecular study estimated the divergence time between the two coelacanth species to be 40 to 30 million years ago (Inoue et al. 2005).  
  
On May 19, 2007, Justinus Lahama, an Indonesian fisherman, caught a 1.3-metre-long, 50kg/110 pound coelacanth off the coast near Manado, on northern Sulawesi Island near Bunaken National Marine Park. After spending 30 minutes out of water, the fish, still alive, was placed in a netted pool in front of a restaurant at the edge of the sea. It survived for 17 hours. Coelacanths, closely related to lungfish, usually live at depths of 200-1,000 metres. The fish was filmed by local authorities swimming in the metre-deep pool, then frozen after it died. AFP claim French, Japanese and Indonesian scientists working with the French Institute for Development and Research carried out a [[necropsy]] on the coelacanth with genetic analysis to follow.
+
On May 19, 2007, Justinus Lahama, an Indonesian fisherman, caught a 1.3-meter-long, 50-kilogram (110-pound) coelacanth off the coast near Manado, on northern Sulawesi Island near Bunaken National Marine Park. After spending 30 minutes out of water, the fish, still alive, was placed in a netted pool in front of a restaurant at the edge of the sea. It survived for 17 hours. Coelacanths, closely related to lungfish, usually live at depths of 200 to 1,000 meters. The fish was filmed by local authorities swimming in the meter-deep pool, then frozen after it died. Scientists working with the French Institute for Development and Research carried out a [[necropsy]] on the coelacanth with genetic analysis to follow.
The local university is now studying the carcass.<ref> [http://www.cosmosmagazine.com/node/1504 "Ancient Indonesian fish is 'living fossil'"], ''Cosmos Online'', [[2007-07-29]].</ref><ref name="CNN1"/>
 
  
 
===St. Lucia Marine Protected Area in South Africa===
 
===St. Lucia Marine Protected Area in South Africa===
In [[South Africa]], the search continued on and off over the years. 46-year-old diver Riaan Bouwer lost his life searching for coelacanths in June 1998.
+
In [[South Africa]], the search continued on and off over the years. On October 28, 2000, just south of the [[Mozambique]] border in [[Sodwana Bay]] in the [[Greater St. Lucia Wetland Park|St. Lucia Marine Protected Area]], three deep-water divers, Pieter Venter, Peter Timm, and Etienne le Roux, made a dive to 104 meters and unexpectedly spotted a coelacanth.
 
 
On the 28th of October 2000, just south of the [[Mozambique]] border in [[Sodwana Bay]] in the [[Greater St. Lucia Wetland Park|St. Lucia Marine Protected Area]], three deep-water divers, Pieter Venter, Peter Timm, and Etienne le Roux, made a dive to 104 metres and unexpectedly spotted a coelacanth.
 
  
Calling themselves "SA Coelacanth Expedition 2000", the group returned with photographic equipment and several additional members. On the 27th of November, after an unsuccessful initial dive the previous day, four members of the group, Pieter Venter, Gilbert Gunn, Christo Serfontein, and Dennis Harding, found three coelacanths. The largest was between 1.5 and 1.8 metres in length; the other two were from 1 to 1.2 metres. The fish swam head-down and appeared to be feeding from the cavern ledges. The group returned with video footage and photographs of the coelacanths.
+
Calling themselves "SA Coelacanth Expedition 2000," the group returned with photographic equipment and several additional members. On the 27th of November, after an unsuccessful initial dive the previous day, four members of the group, Pieter Venter, Gilbert Gunn, Christo Serfontein, and Dennis Harding, found three coelacanths. The largest was between 1.5 and 1.8 meters in length; the other two were from 1 to 1.2 meters. The fish swam head-down and appeared to be feeding from the cavern ledges. The group returned with video footage and photographs of the coelacanths.
  
During the dive, however, Serfontein lost consciousness, and 34-year-old Dennis Harding rose to the surface with him in an uncontrolled ascent. Harding complained of neck pains and died from a [[cerebral embolism]] while on the boat. Serfontein recovered after being taken underwater for [[decompression sickness]] treatment.
+
During the dive, however, Serfontein lost consciousness, and 34-year-old Dennis Harding rose to the surface with him in an uncontrolled ascent. Harding complained of neck pains and died from a [[cerebral embolism]] while on the boat. Serfontein recovered after being taken underwater for [[decompression sickness]] treatment.
  
In March–April of 2002, the Jago Submersible and Fricke Dive Team descended into the depths off Sodwana and observed fifteen coelacanths. A [[dart probe]] was used to collect tissue samples.
+
In March–April of 2002, the Jago Submersible and Fricke Dive Team descended into the depths off Sodwana and observed fifteen coelacanths. A [[dart probe]] was used to collect tissue samples.
  
The shallowest recorded sighting of a coelacanth is at a depth of 58 m off the coast of Sodwana Bay by Christo Vanjaarsveld.
+
The shallowest recorded sighting of a coelacanth is at a depth of 58 meters off the coast of Sodwana Bay by Christo Vanjaarsveld.
  
 
===Tanzania===
 
===Tanzania===
Coelacanths have been caught off the coast of [[Tanzania]] since 2004. Two coelacanths were initially reported captured in Kigombe, a small village off the edge of the [[Indian Ocean]] in August 2004. A spate of 19 more specimens of these extremely rare fishes weighing between 25 kg. to 80 kg. were reported netted in the space of the next 5 months, with another specimen captured in January 2005. A coelacanth weighing as much as 110 kg. was reported by [[the Observer]] newspaper in 2006. Officials of the ''Tanga Coastal Zone Conservation and Development Programme'', which has a long-term strategy for protecting the species, see a connection with the timing of the captures with [[trawling]] - especially by  [[Japan]]ese vessels - near the coelacanth's habitat, as within a couple of days of [[Commercial trawler|trawlers]] casting their nets coelacanths have turned up in shallow-water [[fishing net]]s intended for [[shark]]s. The sudden appearance of the coelacanth off Tanzania that has raised real worries about its future due to damage done to the coelacanth population by the effects of indiscriminate trawling methods and habitat damage.<ref name="tanzania1">[http://observer.guardian.co.uk/world/story/0,16937,1681745,00.html "Dinosaur fish pushed to the brink by deep-sea trawlers"], ''[[The Observer]]'', [[2006-01-08]], Retrieved on [[2007-06-18]].</ref>
+
Coelacanths have been caught off the coast of [[Tanzania]] since 2004. Two coelacanths were initially reported captured in Kigombe, a small village off the edge of the [[Indian Ocean]] in August 2004. A spate of 19 more specimens of these extremely rare fishes, weighing between 25 kilograms to 80 kilograms, were reported netted in the space of the next 5 months, with another specimen captured in January 2005. A coelacanth weighing as much as 110 kilograms was reported by [[the Observer]] newspaper in 2006. Officials of the ''Tanga Coastal Zone Conservation and Development Programme,'' which has a long-term strategy for protecting the species, see a connection with the timing of the captures with [[trawling]]&mdash;especially by  [[Japan]]ese vessels&mdash;near the coelacanth's habitat, as within a couple of days of [[Commercial trawler|trawlers]] casting their nets coelacanths have turned up in shallow-water [[fishing net]]s intended for [[shark]]s. The sudden appearance of the coelacanth off Tanzania has raised real worries about its future due to damage done to the coelacanth population by the effects of indiscriminate trawling methods and habitat damage (Gilmore 2006).
 
 
Hassan Kolombo, a programme co-ordinator, said. "Once we do not have trawlers, we don't get the coelacanths, it's as simple as that." His colleague, Solomon Makoloweka, said they had been pressuring the Tanzanian government to limit trawlers' activities. He said: "I suppose we should be grateful to these trawlers, because they have revealed this amazing and unique fish population. But we are concerned they could destroy these precious things. We want the government to limit their activity and to help fund a proper research program so that we can learn more about the coelacanths and protect them."<ref name="tanzania1"/>
 
  
 
==Taxonomy==
 
==Taxonomy==
 
[[Image:Coelacanth specimen NHM.jpg|thumb|right|250px|A preserved Coelacanth specimen in the [[Natural History Museum]], London]]
 
[[Image:Coelacanth specimen NHM.jpg|thumb|right|250px|A preserved Coelacanth specimen in the [[Natural History Museum]], London]]
 
[[Image:Fishapods.jpg|thumb|right|350px|In [[Devonian|Late Devonian]] [[vertebrate]] speciation, descendants of [[Pelagic zone|pelagic]] [[Sarcopterygii|lobe-finned fish]] – like ''[[Eusthenopteron]]'' – exhibited a sequence of adaptations:<ul>
 
[[Image:Fishapods.jpg|thumb|right|350px|In [[Devonian|Late Devonian]] [[vertebrate]] speciation, descendants of [[Pelagic zone|pelagic]] [[Sarcopterygii|lobe-finned fish]] – like ''[[Eusthenopteron]]'' – exhibited a sequence of adaptations:<ul>
<li>''[[Panderichthys]]'', suited to muddy shallows;
+
<li>''[[Panderichthys]],'' suited to muddy shallows;
 
<li>''[[Tiktaalik]]'' with limb-like fins that could take it up onto land;
 
<li>''[[Tiktaalik]]'' with limb-like fins that could take it up onto land;
 
<li>[[Tetrapod|Early tetrapods]] in weed-filled swamps, such as:<ul>
 
<li>[[Tetrapod|Early tetrapods]] in weed-filled swamps, such as:<ul>
Line 170: Line 152:
 
Descendants also included pelagic lobe-finned fish such as coelacanth species.]]
 
Descendants also included pelagic lobe-finned fish such as coelacanth species.]]
  
Subclass Coelacanthimorpha (Actinistia) are sometimes used to designate the group of [[Sarcopterygii|Sarcopterygian]] fish that contains the Coelacanthiformes. The following is a classification of known coelacanth genera and families:<ref name="Nelson"/>
+
Subclass Coelacanthimorpha (Actinistia) are sometimes used to designate the group of [[Sarcopterygii|Sarcopterygian]] fish that contains the Coelacanthiformes. The following is a classification of known coelacanth genera and families (Nelson 2006):
  
 
'''Class [[Sarcopterygii]]'''<br/>
 
'''Class [[Sarcopterygii]]'''<br/>
 
'''Subclass [[Coelacanthimorpha]]'''<br/>
 
'''Subclass [[Coelacanthimorpha]]'''<br/>
 
* '''Order COELACANTHIFORMES'''
 
* '''Order COELACANTHIFORMES'''
** '''Family Coelacanthidae''' (extinct)
+
** '''Family Coelacanthidae''' [[extinction|†]]
*** ''[[Axelia]]'' (extinct)
+
*** ''[[Axelia]]'' [[extinction|†]]
*** ''[[Coelacanthus]]'' (extinct)
+
*** ''[[Coelacanthus]]'' [[extinction|†]]
*** ''[[Ticinepomis]]'' (extinct)
+
*** ''[[Ticinepomis]]'' [[extinction|†]]
*** ''[[Wimania]]'' (extinct)
+
*** ''[[Wimania]]'' [[extinction|†]]
** '''Family Diplocercidae''' (extinct)
+
** '''Family Diplocercidae''' [[extinction|†]]
*** ''[[Diplocercides]]'' (extinct)
+
*** ''[[Diplocercides]]'' [[extinction|†]]
** '''Family Hadronectoridae''' (extinct)
+
** '''Family Hadronectoridae''' [[extinction|†]]
*** ''[[Allenypterus]]'' (extinct)
+
*** ''[[Allenypterus]]'' [[extinction|†]]
*** ''[[Hadronector]]'' (extinct)
+
*** ''[[Hadronector]]'' [[extinction|†]]
*** ''[[Polyosteorhynchus]]'' (extinct)
+
*** ''[[Polyosteorhynchus]]'' [[extinction|†]]
** '''Family Mawsoniidae''' (extinct)
+
** '''Family Mawsoniidae''' [[extinction|†]]
*** ''[[Alcoveria]]'' (extinct)
+
*** ''[[Alcoveria]]'' [[extinction|†]]
*** ''[[Axelrodichthys]]'' (extinct)
+
*** ''[[Axelrodichthys]]'' [[extinction|†]]
*** ''[[Chinlea]]'' (extinct)
+
*** ''[[Chinlea]]'' [[extinction|†]]
*** ''[[Diplurus]]'' (extinct)
+
*** ''[[Diplurus]]'' [[extinction|†]]
*** ''[[Holophagus]]'' (extinct)
+
*** ''[[Holophagus]]'' [[extinction|†]]
*** ''[[Mawsonia]]'' (extinct)
+
*** ''[[Mawsonia]]'' [[extinction|†]]
** '''Family Miguashaiidae''' (extinct)
+
** '''Family Miguashaiidae''' [[extinction|†]]
*** ''[[Miguashaia]]'' (extinct)
+
*** ''[[Miguashaia]]'' [[extinction|†]]
 
** '''Family Latimeriidae'''
 
** '''Family Latimeriidae'''
*** ''[[Holophagus]]'' (extinct)
+
*** ''[[Holophagus]]'' [[extinction|†]]
*** ''[[Libys]]'' (extinct)
+
*** ''[[Libys]]'' [[extinction|†]]
*** ''[[Macropoma]]'' (extinct)
+
*** ''[[Macropoma]]'' [[extinction|†]]
*** ''[[Macropomoides]]'' (extinct)
+
*** ''[[Macropomoides]]'' [[extinction|†]]
*** ''[[Megacoelacanthus]]'' (extinct)
+
*** ''[[Megacoelacanthus]]'' [[extinction|†]]
 
*** ''Latimeria'' (James Leonard Brierley Smith, 1939)
 
*** ''Latimeria'' (James Leonard Brierley Smith, 1939)
 
**** ''L. chalumnae'' (Comorese coelacanth) (James Leonard Brierley Smith, 1939)
 
**** ''L. chalumnae'' (Comorese coelacanth) (James Leonard Brierley Smith, 1939)
 
**** ''L. menadoensis'' (Indonesian coelacanth) (Pouyaud, Wirjoatmodjo, Rachmatika, Tjakrawidjaja, et al., 1999)
 
**** ''L. menadoensis'' (Indonesian coelacanth) (Pouyaud, Wirjoatmodjo, Rachmatika, Tjakrawidjaja, et al., 1999)
*** ''[[Undina (fish)|Undina]]'' (extinct)
+
*** ''[[Undina (fish)|Undina]]'' [[extinction|†]]
** '''Family Laugiidae''' (extinct)
+
** '''Family Laugiidae''' [[extinction|†]]
*** ''[[Coccoderma]]'' (extinct)
+
*** ''[[Coccoderma]]'' [[extinction|†]]
*** ''[[Laugia]]'' (extinct)
+
*** ''[[Laugia]]'' [[extinction|†]]
** '''Family Rhabdodermatidae''' (extinct)
+
** '''Family Rhabdodermatidae''' [[extinction|†]]
*** ''[[Caridosuctor]]'' (extinct)
+
*** ''[[Caridosuctor]]'' [[extinction|†]]
*** ''[[Rhabdoderma]]'' (extinct)
+
*** ''[[Rhabdoderma]]'' [[extinction|†]]
** '''Family Whiteiidae''' (extinct)
+
** '''Family Whiteiidae''' [[extinction|†]]
*** ''[[Whiteia]]'' (still living)
+
*** ''[[Whiteia]]'' [[extinction|†]]
  
 +
==Notes==
 +
<references/>
  
The following taxonomy is drawn from Nelson (2006).
+
==References==
  
* '''Class SARCOPTERYGII'''
+
* Burgess, M. 2006. [http://www.int.iol.co.za/index.php?set_id=1&click_id=31&art_id=qw1156833901231B223 Oz fossil sheds light on mankind's evolution]. ''IOL'' August 29, 2006. Retrieved July 20, 2008.
:* '''Subclass [[Coelacanthimorpha]]'''
 
:::::'''Order Coelacanthiformes''' ([[coelacanth]]s)
 
::::::Family Miguashaiidae [[extinction|†]]
 
::::::Family Diplocericidae [[extinction|†]]
 
::::::Family Hadronectoridae [[extinction|†]]
 
::::::Family Rhabdodermatidae [[extinction|†]]
 
::::::Family Laugiidae [[extinction|†]]
 
::::::Family Whiteiidae [[extinction|†]]
 
::::::Family Caelacanthidae [[extinction|†]]
 
::::::Family Mawsoniidae [[extinction|†]]
 
::::::'''Family Latimeriidae''' (coelacanths or gombessas)
 
:::::::Genus ''Latimeria''
 
::::::::'''Species ''Latimeria chalumnae'''''
 
::::::::'''Species ''Latimeria menadoesnis'''''
 
:::::::Genus ''Holophagus'' [[extinction|†]]
 
:::::::Genus ''Libys'' [[extinction|†]]
 
:::::::Genus ''Macropoma'' [[extinction|†]]
 
:::::::Genus ''Undina'' [[extinction|†]]
 
:* '''Subclass Dipnotetrapodomorpha''' (includes lungfishes)
 
  
==The coelacanth in popular culture==
+
* Clack, J. A. 2002. ''Gaining Ground: The Origin and Evolution of Tetrapods.'' Bloomington, IN: Indiana University Press. ISBN 0253340543.
{{trivia|date=July 2008}}
 
[[Image:KMF 5 obv.JPG|right|thumb|130px|A [[Comorian franc|Comorian 5 franc]] coin with an image of the coelacanth.]]
 
  
The coelacanths' widely-published status as a "[[living fossil]]" earned it a place in music, video games, literature, and television. "Coelacanth" is the title of songs and albums by bands including  [[John Fahey (musician)|John Fahey]], [[Shriekback]], [[Mr. Children]] and [[Polysics]]. Coelacanths are also heavily featured in video games. The coelacanth appears in games such as ''[[Animal Crossing]]'',<ref>[http://www.dinofish.com/image28.html "Nintendocanth"]</ref>, [[Megaman X2]], ''[[SEGA Marine Fishing]]'', ''[[E.V.O.: Search for Eden]]'' (dubbed "Coelafish"), ''[[We Love Katamari]]'', ''[[Me and My Katamari]]'', and ''[[Endless Ocean]]''. The Coelacanth was also the inspiration for the Pokémon [[Relicanth]],<ref>[http://www.dinofish.com/replicanth.html "Relicanth"]. Retrieved on [[2007]]-[[January 13|1-13]].</ref> the [[Digimon]] [[Coelamon]], (a flying Coelacanth), and [[Boss (video games)|bosses]] in the [[Darius series]].<ref>[http://www.dinofish.com/image22.html Cyber Coelacanth]. Retrieved on [[2007]]-[[January 13|1-13]]].</ref>
+
* Erdmann, M. V. 1999. [http://www.springerlink.com/content/u5143r02v5u7133j An account of the first living coelacanth known to scientists from Indonesian waters]. ''Environmental Biology of Fishes'' 54(4): 439–443. Retrieved July 20,2008.
  
In [[Margaret Atwood]]'s novel ''Oryx and Crake'', the coelacanth is used as a symbol for the underground scientific association Extinctathon. In ''[[Dirk Gently's Holistic Detective Agency]]'', [[Professor Chronotis]] admits to causing the extinction of the [[dodo]]s by trying to save the Coelacanth. In [[Lee Battersby]]'s ''Father Muerte and the Rain'', coelacanths rain from the sky when an ancient butterfly is stolen from its home time. The reference to the Latimeria Chalumnae is also a recurring one in Anne Landsman's novel, ''The Rowing Lesson'', which is set, in part, in pre-World War II South Africa.  Specific reference is made to the coelacanth's discovery as part of the narrative and as an allegorical reference to one's connection with the past.
+
* Fricke, H. 1988. Coelacanths: The fish that time forgot. ''National Geographic'' 173 (6): 824–828.  
  
Coelocanths have featured in film and TV series such as ''[[Atlantis: The Lost Empire]]'', ''[[Monster on the Campus]]'' and ''[[Futurama]]''.  
+
* Gilmore, I. 2006. [http://observer.guardian.co.uk/world/story/0,16937,1681745,00.html Dinosaur fish pushed to the brink by deep-sea trawlers]. ''The Observer'' January 8, 2006. Retrieved July 20, 2008.  
  
The sculptress [[Jeanne Grut]] produced two [[faience]] figures of coelacanths for the [[Royal Copenhagen]] porcelain manufactory in a series known as 'Blue Fish'. Originally made in 1963, these are still produced today.<ref>[http://www.royalcopenhagen.com/Figurines/Blue-Fish.aspx 'Blue Fish' series, Royal Copenhagen website]. Retrieved: June 13, 2008.</ref>
+
* Inoue J. G., M. Miya, B. Venkatesh, and M. Nishida. 2005. The mitochondrial genome of Indonesian coelacanth ''Latimeria menadoensis'' (Sarcopterygii: Coelacanthiformes) and divergence time estimation between the two coelacanths. ''Gene'' 349: 227-235.
  
Finally, coelacanths have been used as symbols in objects and as nicknames. "Les Coelecantes" (meaning "the Coelacanths") is a nickname for the [[Comoros national football team]]. Coelacanths have been shown on coins,<ref>[http://www.dinofish.com/image26.html "Coincanth"]. Retrieved on [[2007]]-[[January 13|1-13]].</ref> phone cards,<ref>[http://www.dinofish.com/image19.html "Phonecanth"]. [[2007]]-[[January 1|1-13]].</ref> and beer bottles.<ref>[http://www.dinofish.com/image18.html "Beercanth"]. Retrieved on [[2007]]-[[January 13|1-13]].</ref>
+
* Jewett, S. L. 1998. [http://www.washingtonpost.com/wp-srv/national/horizon/nov98/fishstory.htm On the trail of the coelacanth, a living fossil]. ''The Washington Post'', November 11, 1998. Retrieved July 20, 2008.  
  
==References==
+
* McAllister, Don E. ''Old Four Legs: A Living Fossil.'' Canadian Government Publishing, 1999. ISBN 0660020009.
{{reflist|2}}
+
 
 +
* Nelson, J. S. 2006. ''Fishes of the World,'' 4th edition. Hoboken, NJ: John Wiley & Sons. ISBN 0471250317.
  
* Clack, J. A. 2002. ''Gaining Ground: The Origin and Evolution of Tetrapods''. Bloomington, Ind: Indiana University Press. ISBN 0253340543.
+
* Pouyaud, L., S. Wirjoatmodjo, I.Rachmatika, A. Tjakrawidjaja, R. Hadiaty, and W. Hadie. 1999. Une nouvelle espece de coelacanthe. Preuves genetiques et morphologiques. ''C. R. Acad. Scie. Paris, Sci. Vie'' 322: 261-267.  
  
* Nelson, J. S. 2006. ''Fishes of the World'', 4th edition. Hoboken, NJ: John Wiley & Sons. ISBN 0471250317.
+
* Weinberg, S. 2000. ''A Fish Caught in Time: The Search for the Coelacanth''. New York, NY: HarperCollins Publishers. ISBN 0060194952.
  
 
==External links==
 
==External links==
{{portal|Fish}}
+
All links retrieved March 8, 2017.
{{portal|Paleontology}}
+
* [http://www.dinofish.com/ DINOFISH .com] Coelacanth: the fish out of time
{{commons|Latimeria chalumnae}}
+
* [http://marinebio.org/species.asp?id=54 Coelacanth] at MarineBio.org.
{{wikispecies|Latimeria}}
+
* [http://www.pbs.org/wgbh/nova/fish/anatomy.html PBS: NOVA - Anatomy of the Coelacanth].  
* [http://www.acep.co.za/ African Coelacanth Ecosystem Programme] ([[ACEP]]), as the South African Coelacanth Conservation and Genome Resource Programme
+
* [http://www.geocities.jp/ancientfishtree/Coelacanth.html Divergence time estimation] of the two coelacanths species based on the whole [[mitochondrial genome]] sequences.  
* [http://www.dinofish.com/ DINOFISH .com] Coelacanth: the fish out of time
 
* [http://marinebio.org/species.asp?id=54 Coelacanth] at MarineBio.org
 
* [http://www.pbs.org/wgbh/nova/fish/anatomy.html PBS: NOVA - Anatomy of the Coelacanth]
 
* [http://www.coelacanth-diver.co.za/ Diving for Coelacanths]
 
* [http://www.geocities.jp/ancientfishtree/Coelacanth.html Divergence time estimation] of the two coelacanths species based on the whole [[mitochondrial genome]] sequences.
 
* [http://www.seasky.org/monsters/sea7a1b.html Coelacanth Information]
 
<!---
 
 
 
Before adding new links here, please make sure the article need the link.
 
For Wikipedia guidelines see [[Wikipedia:External links]].  Thanks.
 
 
 
---->
 
  
{{Sarcopterygii}}
 
  
 
[[Category:Life sciences]]
 
[[Category:Life sciences]]

Revision as of 18:38, 12 March 2020

Coelacanth
Fossil range: Devonian - Recent
Latimeria chalumnae
Latimeria chalumnae
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sarcopterygii
Subclass: Coelacanthimorpha (Actinistia)
Order: Coelacanthiformes
Berg, 1937
Families

See text.

Coelacanth is any sarcopterygian fish of the subclass Coelacanthimorpha (Actinistia) and order Coelacanthiformes, characterized by a three-lobed, diphycercal caudal fin, external nostrils, and an anterior dorsal fin in front of the center of the body (Nelson 2004). While coelacanths are well recognized in the fossil record, there are only two living species, Latimeria chalumne and Latimeria menadoensis (Nelson 2006).

The coelacanths, which are related to lungfishes and tetrapods, were believed to have been extinct since the end of the Cretaceous period, until the first Latimeria specimen (L. chalumne) was found off the east coast of South Africa in 1938. It would be 14 years before a second specimen was captured and another 45 years before another species was identified. The discovery of fish known only from the fossil record has been an exciting story of discovery, propelling an otherwise very rare fish to the forefront of popularity.

Overview and description

Coelacanths, together with lungfish, are part of the vertebrate class Sarcopterygii. The bony fish representatives of this class, known as lobe-finned fish, are characterized by lobed paired fins, which are joined to the body by a single bone (Clack 2002). Sarcopterygians also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of actinopterygians (ray-finned fishes). The braincase of sarcoptergygians primitively has a hinge line, but this is lost in tetrapods and lungfish. Many early sarcoptergians have a symmetrical tail. Some taxonomists also include the tetrapods (amphibians, reptiles, birds, mammals) in Sacropterygii in order to make this a monophyletic group (Nelson 2006).

The coelacanths are placed in the subclass Coelacanthimorpha, while the lungfish traditionally are placed in the subclass Dipnoi, although Nelson (2006) designates Dipnotetrapodomorpha as the subclass with lungfish,

Coelacanthimorpha includes one order, Coelacanthiformes. Within Coelacanthiformes, Nelson (2006) recognizes nine families, of which eight include only fossil members and one includes two living species of coelacanth as well as fossil members. Coelacanths (order Coelacanthiformes), living and extinct, are characterized by a diphycercal caudal fin (having a tail fin with the vertebral column extending to the tip, with symmetrical lower and upper parts), and an anterior dorsal fin in front of the center of the body (Nelson 2004). Coelacanths are lobe-finned fish with the pectoral and anal fins on fleshy stalks supported by bones, and the tail or caudal fin is divided into three lobes, the middle one of which also includes a continuation of the notochord. Coelacanths have modified cosmoid scales, which are thinner than true cosmoid scales, which can only be found on extinct fish. Extant coelacanths also have a special electroreceptive device called a rostral organ in the front of the skull, which probably helps in prey detection. The small device also could help the balance of the fish, as echolocation could be a factor in the way this fish moves.

Coelacanth (pronounced /ˈsiːləkænθ/) is an adaptation of Modern Latin Cœlacanthus > cœl-us + acanth-us from Greek κοῖλ-ος [hollow] + ἄκανθ-α [spine]). This is an order of fish that includes the oldest living lineage of gnathostomata known to date.

Living species

There are two living species of coelacanths, Latimeria chalumne and L. menadoensis (Nelson 2006). These are placed in the family Latimeriidae. The first living species ever found, Latimeria chalumnae, is a marine species. It was first found off of South Africa in 1938. Since 1938, Latimeria chalumnae have been found in the Comoros, Kenya, Tanzania, Mozambique, Madagascar, and in Greater St. Lucia Wetland Park in South Africa. Adults reach 1.8 meters and it has an unusual method of swimming in keeping its body rigid (Nelson 2006). It is the only living chordate with an intracranial joint, although this feature appears in other coelacanths (Nelson 2006). It is live-bearing.

The second species, L. menadoensis, was described by Pouyaud et al. in 1999, after first being sighted in an Indonesian fish market in 1997 and the preservation of a second specimen in 1998 (Nelson 2006; Erdmann 1999). Erdmann (1999) documented these events in a 1999 issue of Environmental Biology of Fishes.

Fossil record

Coelacanths first appear in the fossil record in the Middle Devonian, about 410 million years ago. A fossil coelacanth jaw found in a stratum datable 410 mya that was collected near Buchan in Victoria, Australia's East Gippsland, currently holds the record for oldest coelacanth; it was given the name Eoactinistia foreyi when it was published in September 2006 (Burgess 2006). Prehistoric species of coelacanth lived in many bodies of water in Late Paleozoic and Mesozoic times.

Although now represented by only two known living species, as a group the coelacanths were once very successful with many genera and species that left an abundant fossil record from the Devonian to the end of the Cretaceous period, at which point they apparently suffered a nearly complete extinction. It is often claimed that the coelacanth has remained unchanged for millions of years, but, in fact, the living species and even genus are unknown from the fossil record. However, some of the extinct species, particularly those of the last known fossil coelacanth, the Cretaceous genus Macropoma, closely resemble the living species.

Latimeria, the modern coelacanth

Modern Coelacanths
Fossil range: Recent
Latimeria chalumnae
Latimeria chalumnae
Conservation status
Status iucn3.1 CR.svg
Critically endangered

(IUCN)

Scientific classification
Order: Coelacanthiformes
Family: Latimeriidae
Genus: Latimeria
Smith, 1939
Species
  • L. chalumnae (type)
  • L. menadoensis Pouyaud et al., 1999

The average weight of the living West Indian Ocean coelacanth, Latimeria chalumnae, is 80 kilograms (176 pounds), and they can reach up to 2 meters (6.5 feet) in length. Adult females are slightly larger than males. Based on growth rings in their ear bones (otoliths), scientists infer that individual coelacanths may live as long as 80 to 100 years. Coelacanths live as deep as 700 meters (2300 feet) below sea level, but are more usually found at depths of 90 to 200 meters. Living examples of Latimeria chalumnae have a deep blue color, which probably camouflages them from prey species; however, the Indonesian species is brown. Latimeria chalumnae is widely but very sparsely distributed around the rim of the western Indian Ocean, from South Africa northward along the east African coast to Kenya, the Comoro Island and Madagascar, seemingly occurring in small colonies.

Coelacanth eyes are very sensitive, and have a tapetum lucidum. Coelacanths are almost never caught in the daytime or on nights with full moons, due to the sensitivity of their eyes. Coelacanth eyes also have many rods: receptors in the retina that help animals see in dim light. Together, the rods and tapetum help the fish see better in dark water.

Coelacanth model in the Oxford University Museum of Natural History

Coelacanths are opportunistic feeders, hunting cuttlefish, squid, snipe eels, small sharks, and other fish found in their deep reef and volcanic slope habitats. Coelacanths are also known to swim head down, backwards, or belly up to locate their prey, presumably utilizing their rostral gland. Scientists suspect that one reason this fish has been so successful is that specimens are able to slow down their metabolisms at will, sinking into the less-inhabited depths and minimizing their nutritional requirements in a sort of hibernation mode.

The coelacanths that live near Sodwana Bay, South Africa rest in caves at depths of 90 to 150 meters during daylight hours, but disperse and swim to depths as shallow as 55 meters when hunting at night. The depth is not as important as their need for very dim light and, more importantly, for water which has a temperature of 14 to 22°C. They will rise or sink to find these conditions. The amount of oxygen that their blood can absorb from the water through the gills is dependent on water temperature. Scientific research suggests that the coelacanth must stay in cold, well-oxygenated water or else their blood cannot absorb enough oxygen (Weinberg 2000).

In accordance with the Convention on International Trade of Endangered Species treaty, the coelacanth was added to Appendix I (threatened with extinction) in 1989. The treaty forbids international trade for commercial purposes and regulates all trade, including sending specimens to museums, through a system of permits. In 1998, the total coelacanth population was estimated to have been 500 or fewer, a number that would threaten the survival of the species (Jewett 1998).

Female coelacanths give birth to live young, called "pups," in groups of between 5 and 25 fry at a time; the pups are capable of surviving on their own immediately after birth. Their reproductive behaviors are not well known, but it is believed that they are not sexually mature until after 20 years of age. Gestation time is 13 months.

History of discoveries

Timeline of discoveries[1][2]
Date Description
1938 (December 23) Discovery of the first modern coelacanth 30 kilometers SW of East London, South Africa.
1952 (December 21) Second specimen identified in the Comoros. Since then more than 200 have been caught around the islands.
1988 First photographs of coelacanths in their natural habitat, by Hans Fricke off Grande Comore.
1991 First coelacanth identified near Mozambique, 24 kilometers offshore NE of Quelimane.
1995 First recorded coelacanth on Madagascar, 30 kilometers S of Tuléar.
1997 (September 18) New species of coelacanth found in Indonesia.
2000 A group found by divers off Sodwana Bay, South Africa.
2001 A group found off the coast of Kenya.
2003 First coelacanth caught by fisherman in Tanzania. Within the year, 22 were caught in total.
2004 Canadian researcher William Sommers captured the largest recorded specimen of coelacanth off the coast of Madagascar.
2007 (May 19) Indonesian fisherman Justinus Lahama caught a 1.31-meter-long (4.30-foot-long), 51-kilogram (112-pound) coelacanth off Sulawesi Island, near Bunaken National Marine Park, that survived for 17 hours in a quarantined pool.
2007 (July 15) Two fishermen from Zanzibar caught a coelacanth measuring 1.34 meters (4.40 feet), and weighing 27 kilograms (60 pounds). The fish was caught off the north tip of the island, off the coast of Tanzania.

First find in South Africa

On December 23, 1938, Hendrik Goosen, the captain of the trawler Nerine, returned to the harbor at East London, South Africa, after a trawl around the mouth of the Chalumna River. As he frequently did, he telephoned his friend, Marjorie Courtenay-Latimer, curator at East London's small museum, to see if she wanted to look over the contents of the catch for anything interesting. At the harbor, Latimer noticed a blue fin and took a closer look. There she found what she later described as "the most beautiful fish I had ever seen, five feet long, and a pale mauve blue with iridescent silver markings."

Failing to find a description of the creature in any of her books, she attempted to contact her friend, Professor James Leonard Brierley Smith, but he was away for Christmas. Unable to preserve the fish, she reluctantly sent it to a taxidermist. When Smith returned, he immediately recognized it as a coelacanth, the group known previously only from fossils. Smith named the fish Latimeria chalumnae in honor of Marjorie Courtenay-Latimer and the waters in which it was found. The two discoverers received immediate recognition, and the fish became known as a "living fossil." The 1938 coelacanth is still on display in the East London, South Africa, museum.

However, as the specimen had been stuffed, the gills and skeleton were not available for examination, and some doubt therefore remained as to its identity. Smith began a hunt for a second specimen that would take more than a decade.

Comoros

name= }}.

A worldwide search was launched for more coelacanths, with a reward of 100 British pounds, a very substantial sum to the average South African fisherman of the time. Fourteen years later, one specimen was found in the Comoros, but the fish was no stranger to the locals—in the port of Mutsamudu on the Comorian island of Anjouan, the Comorians were puzzled to be so rewarded for a "gombessa" or "mame," their names for the nearly inedible fish that their fishermen occasionally caught by mistake.

The second specimen, found in 1952 by Comorian fisherman Ahamadi Abdallah, was described as a different species, first as Malania hunti and later as Malania anjounae, after Daniel François Malan, the South African Prime Minister who had dispatched an SAAF Dakota at the behest of Professor Smith to fetch the specimen. It was later discovered that the lack of a first dorsal fin, at first thought to be significant, was caused by an injury early in the specimen's life. Ironically, Malan was a staunch creationist; when he was first shown the primitive creature, he exclaimed, with a twinkle, "My, it is ugly. Do you mean to say we once looked like that?" (Weinberg 2000). The specimen retrieved by Smith is on display at the SAIAB in Grahamstown, South Africa where he worked.

The Comorians are now aware of the significance of the endangered species and have established a program to return any accidentally-caught coelacanth to deep water.

As for Smith, who died in 1968, his account of the coelacanth story appeared in the book Old Fourlegs, first published in 1956. His book Sea Fishes of the Indian Ocean, illustrated and co-authored by his wife Margaret, remains the standard ichthyological reference for the region.

In 1988, National Geographic photographer Hans Fricke was the first to photograph the species in its natural habitat, 180 meters (590 feet) off Grande Comore's west coast (Fricke 1988).

Second species in Indonesia

On September 18, 1997, Arnaz and Mark Erdmann, traveling in Indonesia on their honeymoon, saw a strange fish enter the market at Manado Tua, on the island of Sulawesi (Jewett 1998). Mark thought it was a gombessa (Comoros coelacanth), although it was brown, not blue. An expert noticed their pictures on the Internet and realized its significance. Subsequently, the Erdmanns contacted local fishermen and asked for any future catches of the fish to be brought to them. A second Indonesian specimen, 1.2 meters in length and weighing 29 kilograms was captured alive on July 30, 1998 (Nelson 2006). It lived for six hours, allowing scientists to photographically document its coloration, fin movements, and general behavior. The specimen was preserved and donated to the Museum Zoologicum Bogoriense (MZB), part of the Indonesian Institute of Sciences (LIPI) (Jewett 1998).

DNA testing revealed that this specimen differed genetically from the Comorian population. Superficially, the Indonesian coelacanth, locally called raja laut ("King of the Sea"), appears to be the same as those found in the Comoros except that the background coloration of the skin is brownish-gray rather than bluish. This fish was described in by Pouyard et al. in 1999. It was given the scientific name Latimeria menadoensis. A molecular study estimated the divergence time between the two coelacanth species to be 40 to 30 million years ago (Inoue et al. 2005).

On May 19, 2007, Justinus Lahama, an Indonesian fisherman, caught a 1.3-meter-long, 50-kilogram (110-pound) coelacanth off the coast near Manado, on northern Sulawesi Island near Bunaken National Marine Park. After spending 30 minutes out of water, the fish, still alive, was placed in a netted pool in front of a restaurant at the edge of the sea. It survived for 17 hours. Coelacanths, closely related to lungfish, usually live at depths of 200 to 1,000 meters. The fish was filmed by local authorities swimming in the meter-deep pool, then frozen after it died. Scientists working with the French Institute for Development and Research carried out a necropsy on the coelacanth with genetic analysis to follow.

St. Lucia Marine Protected Area in South Africa

In South Africa, the search continued on and off over the years. On October 28, 2000, just south of the Mozambique border in Sodwana Bay in the St. Lucia Marine Protected Area, three deep-water divers, Pieter Venter, Peter Timm, and Etienne le Roux, made a dive to 104 meters and unexpectedly spotted a coelacanth.

Calling themselves "SA Coelacanth Expedition 2000," the group returned with photographic equipment and several additional members. On the 27th of November, after an unsuccessful initial dive the previous day, four members of the group, Pieter Venter, Gilbert Gunn, Christo Serfontein, and Dennis Harding, found three coelacanths. The largest was between 1.5 and 1.8 meters in length; the other two were from 1 to 1.2 meters. The fish swam head-down and appeared to be feeding from the cavern ledges. The group returned with video footage and photographs of the coelacanths.

During the dive, however, Serfontein lost consciousness, and 34-year-old Dennis Harding rose to the surface with him in an uncontrolled ascent. Harding complained of neck pains and died from a cerebral embolism while on the boat. Serfontein recovered after being taken underwater for decompression sickness treatment.

In March–April of 2002, the Jago Submersible and Fricke Dive Team descended into the depths off Sodwana and observed fifteen coelacanths. A dart probe was used to collect tissue samples.

The shallowest recorded sighting of a coelacanth is at a depth of 58 meters off the coast of Sodwana Bay by Christo Vanjaarsveld.

Tanzania

Coelacanths have been caught off the coast of Tanzania since 2004. Two coelacanths were initially reported captured in Kigombe, a small village off the edge of the Indian Ocean in August 2004. A spate of 19 more specimens of these extremely rare fishes, weighing between 25 kilograms to 80 kilograms, were reported netted in the space of the next 5 months, with another specimen captured in January 2005. A coelacanth weighing as much as 110 kilograms was reported by the Observer newspaper in 2006. Officials of the Tanga Coastal Zone Conservation and Development Programme, which has a long-term strategy for protecting the species, see a connection with the timing of the captures with trawling—especially by Japanese vessels—near the coelacanth's habitat, as within a couple of days of trawlers casting their nets coelacanths have turned up in shallow-water fishing nets intended for sharks. The sudden appearance of the coelacanth off Tanzania has raised real worries about its future due to damage done to the coelacanth population by the effects of indiscriminate trawling methods and habitat damage (Gilmore 2006).

Taxonomy

A preserved Coelacanth specimen in the Natural History Museum, London
In Late Devonian vertebrate speciation, descendants of pelagic lobe-finned fish – like Eusthenopteron – exhibited a sequence of adaptations:
  • Panderichthys, suited to muddy shallows;
  • Tiktaalik with limb-like fins that could take it up onto land;
  • Early tetrapods in weed-filled swamps, such as:
    • Acanthostega which had feet with eight digits,
    • Ichthyostega with limbs.
Descendants also included pelagic lobe-finned fish such as coelacanth species.

Subclass Coelacanthimorpha (Actinistia) are sometimes used to designate the group of Sarcopterygian fish that contains the Coelacanthiformes. The following is a classification of known coelacanth genera and families (Nelson 2006):

Class Sarcopterygii
Subclass Coelacanthimorpha

  • Order COELACANTHIFORMES
    • Family Coelacanthidae
    • Family Diplocercidae
      • Diplocercides
    • Family Hadronectoridae
      • Allenypterus
      • Hadronector
      • Polyosteorhynchus
    • Family Mawsoniidae
    • Family Miguashaiidae
    • Family Latimeriidae
      • Holophagus
      • Libys
      • Macropoma
      • Macropomoides
      • Megacoelacanthus
      • Latimeria (James Leonard Brierley Smith, 1939)
        • L. chalumnae (Comorese coelacanth) (James Leonard Brierley Smith, 1939)
        • L. menadoensis (Indonesian coelacanth) (Pouyaud, Wirjoatmodjo, Rachmatika, Tjakrawidjaja, et al., 1999)
      • Undina
    • Family Laugiidae
    • Family Rhabdodermatidae
      • Caridosuctor
      • Rhabdoderma
    • Family Whiteiidae

Notes

  1. Iziko South African Museum, Cape Town
  2. J. Nelson. Fishes of the World, 4th edition (Hoboken, NJ: John Wiley & Sons, 2006). ISBN 0471250317.

References
ISBN links support NWE through referral fees

  • Clack, J. A. 2002. Gaining Ground: The Origin and Evolution of Tetrapods. Bloomington, IN: Indiana University Press. ISBN 0253340543.
  • Fricke, H. 1988. Coelacanths: The fish that time forgot. National Geographic 173 (6): 824–828.
  • Inoue J. G., M. Miya, B. Venkatesh, and M. Nishida. 2005. The mitochondrial genome of Indonesian coelacanth Latimeria menadoensis (Sarcopterygii: Coelacanthiformes) and divergence time estimation between the two coelacanths. Gene 349: 227-235.
  • McAllister, Don E. Old Four Legs: A Living Fossil. Canadian Government Publishing, 1999. ISBN 0660020009.
  • Nelson, J. S. 2006. Fishes of the World, 4th edition. Hoboken, NJ: John Wiley & Sons. ISBN 0471250317.
  • Pouyaud, L., S. Wirjoatmodjo, I.Rachmatika, A. Tjakrawidjaja, R. Hadiaty, and W. Hadie. 1999. Une nouvelle espece de coelacanthe. Preuves genetiques et morphologiques. C. R. Acad. Scie. Paris, Sci. Vie 322: 261-267.
  • Weinberg, S. 2000. A Fish Caught in Time: The Search for the Coelacanth. New York, NY: HarperCollins Publishers. ISBN 0060194952.

External links

All links retrieved March 8, 2017.

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