Every time I think of squid, two things pass into my mind. First is the monstrous squid that attacked Capt. Nemo’s submarine, the Nautilus, in the wonderful 1954 movie classic Twenty Thousand Leagues Under the Sea, which is based on the Jules Verne novel by the same name.
It was pretty heady stuff for an 8-year-old kid (yes, I really am that old). I can still see Ned the harpooner, played by Kirk Douglas, skewering the monster right between the eyes.
It was one of many things that led me into the field of marine biology.
The second thing is the humorous recollection of what they were almost universally called by Louisiana’s commercial shrimpers of the 1960s and 1970s: “squibs.”
It wasn’t a Cajun thing. Americaines (non-French shrimpers) as well as Cajuns used the term. The term is almost gone now, along with the generation that used it.
The saline waters of the Gulf of Mexico have lots of squid, both of the shortfin and the longfin varieties. However, only one species ventures into brackish waters: the brief squid (Lolliguncula brevis).
References often list the lowest salinity it can be found in at 17 parts per thousand (full-strength seawater is 35 ppt), but Louisiana Department of Wildlife and Fisheries trawl-monitoring data shows catches of brief squid in salinities as low as 6 ppt.
Thirty years ago and earlier, brief squid were found primarily in shallow coastal waters near the shore, but as barrier islands have eroded and coastal lakes and bays, such as Barataria and Terrebonne bays, have become larger and more Gulf-like, brief squid have invaded them and become common inshore.
This little creature has a huge range, extending from southern Canada along the entire coasts of North and South America down to Argentina. But probably nowhere in its range is it as common as in Louisiana waters, probably because of the influence of the Mississippi River.
More than any other squid, the brief squid is able to tolerate low-oxygen (hypoxic) conditions. Even newly hatched brief squid can be found in hypoxic waters, which might help them avoid becoming lunch for larger predators.
With a body length of only 3 ½ inches for males and 4 ½ inches for females, brief squid are well-named. But as small as they are, they are ferocious predators.
While they likely feed on shrimp and other small animals, they seem to have a strong predilection for anchovies, perhaps the most-common fish in the Gulf.
Like other squid, brief squid have two long tentacles and eight shorter arms, at the center of which is a muscular mouth that houses a very hard and sharp, parrot-like beak.
When they spot their prey, they shoot their tentacles out and snare it with the suckers and hooks on their clubbed ends. The tentacles quickly retract the prey to within reach of the eight arms, which hold it firmly while the creature bites and rips chunks out of its victim.
The capture of the prey and their approach toward it happens with blinding speed — so quickly that it is difficult to track individual actions.
Squid have fins, but swim by jet propulsion. They draw water into their body (called the mantle) and squirt it out through a funnel. The funnel can change direction quickly and move the squid forward or backward with equal and lightning-quick speed.
The speed of squids serves well to escape predators, but probably more important is camouflage. Their skins are covered with dark pigment spots called chromatophores. These can be expanded or contracted in size, changing the animals’ coloration to allow them to blend into their surroundings.
When attacked, squid can also discharge quantities of an almost black “ink.” The discharge might serve as a smokescreen to obscure the animal, but it is much more. It is made up mostly of melanin and mucous, what one writer called “pigment and snot.” But it also has tyrosinase, an enzyme that can irritate, numb or even make a predator’s sensory system go haywire.
Squid ink sounds gross, but it is actually used in Mediterranean, particularly Italian, cooking.
Brief squid have short lives — typically only a year. They apparently spawn year-round, and females attach their eggs covered with gelatinous capsules onto the bottom in shallow waters.
Brief squid mate similarly to most but not all other squid.
Males have a modified arm called a hydrocotylus that they use to transfer packets of sperm to females. The exceptions to this rule of squid romance are some species of deepwater squids.
Males in those species have actual penises. One, the greater hooked squid (Onykia ingens), has an organ that is longer than the combined length of its mantle, head, and arms. The only other creatures on earth with longer penises compared to their body length are, of all things, certain barnacles.
Squid eyes are also impressively large. The colossal squid (Mesonychoteuthis hamiltoni), which grows to 46 feet in length, has the largest eyes in the animal kingdom.
Squid eyes are similar in structure to human eyes, but they focus by changing the position of the lenses, as is done with a camera. Humans focus their eyes by changing the shape of their lenses.
Although they are probably close to being deaf — if they can hear at all — they have a very strong sense of smell used for hunting. Their sniffers are located in small pits located beneath their eyes.
Squid are mollusks, typically animals one thinks of as having hard shells. The phylum Mollusca has several classes, including gastropods (meaning stomach-foot in Latin) which are snails and slugs; bivalves (meaning two shells), which are clams and oysters; and cephalopods (meaning head-foot) which includes squids and octopuses.