Ommastrephidae Family – Ommastrephid Squid

Ommastrephid Squid of the Ommastrepihidae Family are Mollusks in the Phylum Molusca and the Class Cephalopoda. This Class includes octopuses, cuttlefish, and nautiloids. Cephalopods are characterized by having a mantle (body), a head, and a foot that is modified into a series of, at least, eight arms. The arms attach to the head and surround the mouth. The arms may be equipped with suckers, hooks, or cirri. Some will have tentacles in addition to their arms. All cephalopods have three hearts. Two hearts pump blood to the gills, and one heart pumps blood to the rest of the body. Cephalopods have blue blood, because they bind oxygen with hemocyanin. Cephalopods have relatively large brains and complex eyes. Cephalopods can change the color of their skin at will, and very quickly. They do this by nerve controlled chromatophores (pigment sacks in the skin), iridiphores (reflect light to appear iridescent), and leucophores (scatter ambient light). Cephalopods also have the ability to squirt “ink” into the water to confuse, or hide from, predators.

Squid are in the Superorder Decapodiformes. Decapodiformes are characterized as having an elongate body, 8 arms, 2 tentacles, large eyes, and an internal shell, known as a gladius or pen. The pen is made of chitin and may be rod or feather shaped. The pen provides rigidity to the body, as well as an attachment point for muscles. The suckers on the arms and tentacles may be located on stalks and have chitinous rings or hooks. The tentacles are modified arms that are usually longer than the arms, are retractile, and terminate in wide, flat lobes (tentacular clubs). The only suckers on the tentacles are located on the tentacular clubs. Fins are attached to the mantle and may be used for swimming, hovering, or maneuvering.

Ommastrephid Squid are in the Order Oegopsida. Oegopsid Squid may have either hooks, or suckers that lack circularis muscles, on their arms and tentacular clubs. Their tentacular clubs have a carpal locking mechanism. Their fins usually join posteriorly and lack a posterior lobe. They do not have a tentacle pocket on their head. They lay their eggs in pelagic masses or strings, as opposed to capsules attached to the substrate. They are generally found in deeper, more open, water than Nearshore of Myopsid Squid.

Squid in the Family Ommastrephidae are muscular strong swimmers. Unfortunately, the key defining characteristics of this Family are not possible to observe in the field. The most accurate characteristic is that their funnel/mantle locking cartilage has an inverted “T” shape. Their gladius is feather-shaped and has a hollow cone structure. They have 2 rows of suckers on their arms and either four or eight rows on their tentacular clubs. Some species have light producing photophores on their skin. Many species in this Family are known as “flying squid, “arrow squid”, or volplaning squid, because of their ability to launch themselves from the water and glide some distance in order to avoid predators. The majority of Ommastrephids are large in stature having mantle lengths up to 1.5 m (5 feet). Their overall lengths may reach 4 m (13 feet).

Ommastrephids are predators that consume fish, shrimp, and squid. Cannibalism is common in this Family. These squid capture prey by swimming toward it with the arms close together, in a cone shape. They quickly shoot out their tentacles to grab their prey with tooth lined suckers. The tentacles and arms quickly drag the prey to their sharp, parrot-like beak. The suckers and beak quickly shred the prey’s flesh. They often hunt in large groups and some species seem to engage in cooperative, pack-style hunting. In turn they are preyed upon by fish, sea birds, toothed whales, pinnipeds, and each other.

The Ommastrephids are the most abundant and widely distributed cephalopod. They are also among the most ecologically diverse. They range in depth from the surface to depths exceeding 2.000 m (6,560 feet). They are found worldwide, from the sub Arctic to the sub Antarctic. Many species in this family are of importance to commercial fisheries. Also, they are used a bait for other commercial fishing species including billfish, swordfish and tuna.

Ommastrephid Squid of the Ommastrepihidae Family have been placed in 11 genera with 22 individual members. Two Ommastrephid Squid are found in Mexico’s coastal waters of the Pacific Ocean.