Squid
| Squid | ||||||||||||
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 Mastigoteuthis flammea
A species of whip-lash squid | ||||||||||||
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Myopsina |
Squid are a large, diverse group of marine cephalopods (Class Cephalopoda) of the order Teuthida (sometimes listed as order or suborder Teuthoidea). Like all cephalopods, squids are characterized by bilateral symmetry, a prominent head, and a modification of the mollusk foot into the form of arms or tentacles surrounding the mouth, which has beak-like jaws.
Squids belong to the subclass Coleoidea along with octopuses, cuttlefish, and extinct belemites. They differ from octopuses in that these have eight arms and no tentacles, while squids and cuttlefish, at some point in their life cycle, have eight arms and two tentacles. (Tentacles tend to be longer than arms and usually have suckers as their tips only.) The suckers of squids also have hooks or sucker rings, while octopuses have simple suckers without secondary armature (O'Shea 2006). Squids differ from the squid-like cuttlefish in that cuttlefish have an internal shell (cuttlebone) on their back, which squid lack. Some squid species lose their tentacles in post-larval stages, and thus the adult only has eight arms (O'Shea 2006).
There are about 300 species of squid, classified into 28 families.
The colossal squid (Mesonychoteuthis hamiltoni) and giant squids (Architeuthisare sp.) are the world's largest invertebrates. Their tentacles are particularly formidable, having powerful suckers and deadly teeth at the ends of the tentacles. The teeth of the Giant Squid are small, "bottle-cap" shaped circular saws, while the tentacles of the Colossal Squid wield two long rows of thick, sharp, finger-length screws of protruding bone.
Description
The majority of squid are no more than 60 centimeters long, although the giant squid may reach 13 meters (40 feet) in length. In 2003, however, a large specimen of an abundant but poorly understood species, Mesonychoteuthis hamiltoni (the Colossal Squid) was discovered. This species may grow to 14 meters in length, making it the largest invertebrate in the world. It also possesses the largest eyes in the animal kingdom. Giant squids are featured in literature and folklore, with a strongly frightening connotation.
Squid have two gills, sometimes called ctenidia, and an extensive closed circulatory system consisting of a systemic heart and two gill hearts.
The tentacles are a type of muscular hydrostat and have suckers. If severed, the tentacles do not grow back.
Squid have chromatophores (pigment-containing and light-reflecting cells) embedded in their skin and can readily blend in with their surroundings to avoid predators. Squids also have the ability to expel ink if threatened.
A squid's bony structure is internalized. There is a single flat plate structure buried within the soft tissue, referred to as the gladius or pen.
Squids have a specialized foot called the siphon, or hyponome, that enables them to move by expelling water under pressure. Squid are the most skilled of the coleoids at this form of jet propulsion. In this method, oxygenated water is taken into the mantle cavity. Through muscular contraction of this cavity, the spent water is expelled through the hyponome, created by a fold in the mantle. Motion of squids is usually backward as water is forced out anteriorly through the hyponome, but direction can be controlled somewhat by pointing it in different directions.
The mouth of the squid is equipped with a sharp horny beak made of chitin, used to kill and tear prey into manageable pieces. Captured whales, which consume squid, often have squid beaks in their stomachs, the beak being the only indigestible part of the squid. The mouth contains the radula (the rough tongue common to all mollusks except bivalvia and aplacophora).
Squid are exclusively carnivorous, feeding on fish and other invertebrates. Squid usually have two elongated tentacles especially for the capture of food. They are voracious, fast-moving, and fast-growing predators, and can be hugely abundant in productive seas. Most live for one year, dying after spawning, although some of the giant species may live for two years or more.
As a food
Many species of squid are popular as food in cuisines as widely separated as Korean and Italian. In English-speaking countries, it is often known by the name calamari, from the Greek-Italian word for these animals.
Individual species of squid are found abundantly in certain areas and provide large catches for fisheries.
When cooking, it is important to keep the cooking time brief as the flesh tends to toughen if overcooked. The body can be stuffed whole, cut into flat pieces or sliced into rings. The tentacles and the ink is also edible; in fact, the only parts of the squid that are not eaten is its beak and the internal bony structure.
There are myriads of ways in which squid is eaten worldwide.
- Fried calamari is one of the most popular ways to cook calamari in the West. Squid rings are coated in batter and deep fried. Often eaten as a snack or an appetizer.
- In the Mediterranean, squid ink is eaten in a variety of dishes such as paella, risotto, soups, and pasta. Squid ink is also sometimes eaten; Spaghetti al Nero di Seppia being an example.
- Bouillabaisse and other seafood stews often contain squid.
- In Chinese and South East Asian cuisine, squid is a common ingredient in a variety of dishes such as stir-fries, rice and noodle dishes. It is often heavily spiced.
- Whole grilled squid is a common food item in Asia; they are popular at food stalls in Thailand and Japan.
- Pre-packaged sun-dried squid and cuttlefish are popular snack items in East Asia, often sold in a shredded form due to its chewiness.
- Squid is a common sushi and sashimi item.
- In Japan and Korea, squid (often Firefly Squid or Spear Squid) is often made into shiokara (in Japanese) or chotkal (in Korean). Heavily salted squid is left to ferment, sometimes with its innards, for up to a month, and is sold in small jars. This salty, strong flavored item is served in small quantities as an accompaniment to white rice or alcoholic drinks.
Classification
Squid are members of the class Cephalopoda, subclass Coleoidea, and order Teuthida, of which there are two major suborders, Myopsina and Oegopsina (including the giant squids like Architeuthis dux). Teuthida is the largest of the cephalopod orders, edging out the octopuses (order Octopoda) for total number of species, with 298 classified into 28 families.
The order Teuthida is a member of the superorder Decapodiformes (from the Greek for "ten legs"). Two other orders of decapodiform cephalopods are also called squid, although they are taxonomically distinct from Teuthida and differ recognizably in their gross anatomical features. They are the bobtail squid of order Sepiolida and the Ram's Horn Squid of the single species order Spirulida. The Vampire Squid is more closely related to the octopuses than to any of the squid, and is generally placed in its own order, Vampyromorphida, in the Octopodiformes superorder.
- CLASS CEPHALOPODA
- Subclass Nautiloidea: nautilus
- Subclass Coleoidea: squid, octopus, cuttlefish
- Superorder Octopodiformes
- Superorder Decapodiformes
- Order Spirulida: Ram's Horn Squid
- Order Sepiida: cuttlefish
- Order Sepiolida: bobtail squid
- Order Teuthida: squid
- Suborder Myopsina
- Family Australiteuthidae
- Family Loliginidae: inshore, calamari, and grass squid
- Suborder Oegopsina
- Family Ancistrocheiridae: Sharpear Enope Squid
- Family Architeuthidae: giant squid
- Family Bathyteuthidae
- Family Batoteuthidae: Bush-club Squid
- Family Brachioteuthidae
- Family Chiroteuthidae
- Family Chtenopterygidae: comb-finned squid
- Family Cranchiidae: glass squid
- Family Cycloteuthidae
- Family Enoploteuthidae
- Family Gonatidae: armhook squid
- Family Histioteuthidae: jewel squid
- Family Joubiniteuthidae: Joubin's Squid
- Family Lepidoteuthidae: Grimaldi Scaled Squid
- Family Lycoteuthidae
- Family Magnapinnidae: bigfin squid
- Family Mastigoteuthidae: whip-lash squid
- Family Neoteuthidae
- Family Octopoteuthidae
- Family Ommastrephidae: flying squid
- Family Onychoteuthidae: hooked squid
- Family Pholidoteuthidae
- Family Promachoteuthidae
- Family Psychroteuthidae: Glacial Squid
- Family Pyroteuthidae: fire squid
- Family Thysanoteuthidae: rhomboid squid
- Family incertae sedis (Parateuthis tunicata)
- Family Walvisteuthidae
- Suborder Myopsina
ReferencesISBN links support NWE through referral fees
- Okuzumi, M, and T. Fufii (eds.). 2000. Nutritional and Functional Properties of Squid and Cuttlefish. Japan: National Cooperative Association of Squid Processors.
- Vecchione, M. 2006. Cephalopods. Mar-Eco. Retrieved January 18, 2007.
Gallery
Caribbean Reef Squid or Sepioteuthis sepioidea
European Squid or Loligo vulgaris
Caught squid drying in a harbor
Dried and packaged squid
- Day239picklebarrelc.JPG
Fried calamari: breaded, deep-fried squid
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