Lolliguncula brevis, or the Atlantic brief squid, is a small species of squid in the Loliginidae family. They are found in shallow parts of the western Atlantic Ocean, through Rio de la Plata, Argentina, as far as the Bay of Fundy. The average female Atlantic brief squid is 11 cm long and the average male is 9 cm. The maximum mantle length ever recorded was 12 cm.

Biology The mantle is widest in the middle and tapers to a rounded point at the back. It 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 (siphon) underneath the head which is used in locomotion. The fins are wider than they are long, rounded and about half the length of the mantle. There are five pairs of appendages.