Lolliguncula (Lolliguncula) brevis (Blainville 1823)

Lolliguncula brevis, or the Atlantic brief squid, is a small species of squid in the Loliginidae family. It is found in shallow parts of the western Atlantic Ocean.^[2]

Distribution

The Atlantic brief squid occurs most frequently in shallow waters along the eastern seaboard of the United States as far north as Delaware. It has also been found in Argentina, Brazil, the British Virgin Islands, Colombia, Mexico, Panama, Puerto Rico, Suriname, Trinidad and Tobago and Venezuela.^[3]

Description

Lolliguncula brevis

The female Atlantic brief squid is about 11 cm long and the male 9 cm. The basic colour is dark reddish-brown to yellow-brown and there are many chromatophores on the upper surface which enable the squid to change colour. The mantle is widest in the middle and tapers to a rounded point at the back. The fins are wider than they are long, rounded and about half the length of the mantle.^[2] The mantle has thick muscular walls and a large water-filled cavity and is separated from the head by a collar. The head has two large eyes, the structure of which is very similar to vertebrate eyes. There is a funnel underneath the head which is used in locomotion. There are five pairs of appendages. Numbers 1, 2, 3 and 5 are short tapering arms with two rows of suckers. The left 5th appendage of males is modified to form a hectocotylus arm which is used to transfer spermatophores into the female reproductive organ. The other pair of appendages are contractile tentacles and are much longer than the arms. These have clubs with four rows of suckers at the distal end and are used for capturing food which is then transferred to the arms. The posterior end of the female mantle is occupied by a pair of white nidamental glands which secrete the material from which the egg capsule is formed.^[4]

Biology

This species is found in warm shallow waters, often at the mouths of rivers where it seems to tolerate low salinity levels. It eats small fish and crustaceans. In order to move, water inside the mantle cavity is expelled through the funnel by muscular contraction of the mantle walls. To catch fast moving prey, the contraction is vigorous, sending a jet of water through the funnel which is directed backwards. To escape a predator, the funnel is directed forwards and the squid shoots backwards at great speed. It can also emit a cloud of ink to distract the predator.^[5] Eggs are deposited in a gelatinous capsule attached to the sea bed.^[2] The large-yolked eggs hatch into fully formed miniature versions of the parent squid.^[5]

References

Lolliguncula brevis

Le calmar court (Lolliguncula brevis) est une espèce de mollusques de la famille des Loliginidae.

Bien que les calmars aient réussi à coloniser toutes les étendues d'eau salée, on ne trouve pas de calmars en eau douce, ni même aucun céphalopode. Toutefois le calmar Lolliguncula brevis, vivant dans la baie de Chesapeake, s'avère être une exception puisqu'il tolère l'eau saumâtre. Dans cette baie, la salinité est aussi faible que 8,5 parties pour mille (environ le quart de celle de l'océan)^[1],[2].

Références

Lolliguncula brevis is een soort in de taxonomische indeling van de inktvissen, een klasse dieren die tot de stam der weekdieren (Mollusca) behoort. De inktvis komt enkel in zout water voor en is in staat om van kleur te veranderen. Hij beweegt zich voort door water in zijn mantel te pompen en het er via de sifon weer krachtig uit te persen. De inktvis is een carnivoor en zijn voedsel bestaat voornamelijk uit vis, krabben, kreeften en weekdieren die ze met de zuignappen op hun grijparmen vangen.

De inktvis komt uit het geslacht Lolliguncula en behoort tot de familie Loliginidae. Lolliguncula brevis werd in 1823 beschreven door Blainville.^[1]