Fantastic Metropolis

Prey

©2001 by Mark Roberts

Although all squid use their tentacles to bring prey within reach of their mouths, they feed in a variety of different ways. Some squid swallow their food and others batter it against underwater rocks to tenderize it. Still other squid, like the mayfly squid, chop up and grind down their food using beak, teeth, and pistolaro (a tongue-like organ).

Mayfly squid will eat anything, including other mayfly squid. Specific prey animals include fish, small birds, crayfish, crabs, small turtles, new-born alligators, and insects. As captured on videotape for the Discovery Channel’s Everglades special, the mayfly squid will sometimes shoot water at insects on overhanging tree branches.(26) The aim of the mayfly squid is surprisingly accurate and even a large beetle will be knocked into the water after two or three tries. Incidences of scavenging from humans are rare.^[15]

Predators

The mayfly squid’s Brazilian equivalent must be wary of birds, catfish, otters, crocodiles, dozens of different types of fish, and giant turtles. Florida alligators and snapping turtles, by contrast, do not appear to like the taste of squid flesh unless other food sources are scarce. Birds constitute a greater threat, but the mayfly squid is usually too quick for great blue herons, ospreys, and anhingas. Smaller birds cannot handle an adult mayfly squid, while avian juveniles, such as ducklings, may find themselves eaten by the squid. Almost all fish love to eat juvenile squid, but few species eat the adult version. Park rangers stationed at Paynes Prairie (Gainesville, Florida) claim to have witnessed otters eating freshwater squid, but this has not been verified by naturalists in the area. And, since the closing down of the Okeechobee squid mills (see Florida Squid Mills, below), humans have ceased to be anything but a secondary threat, through habitat destruction and pollution.

When mayfly squid do find themselves under hostile scrutiny, they use a number of nasty defense mechanisms to discourage these perceived threats (as I can attest to from first-hand experience). The most common consists of lightning-quick color changes designed to interrupt the predator’s normal attack sequence; however, it will continue to change color even while employing its other, escalating, strategies.

If flight is at first impossible, the squid will darken the waters with its green ink and then attempt to flee. Should a predator persist, the squid will eject a cloud of poisonous bacteria from its plocium pouch (located next to the stomach).

Should all of these tactics fail, the mayfly squid will attempt to suffocate its attacker by stuffing its arms and tentacles into any available orifice.^[16] A final (and fatal) defense mechanism-literally turning itself inside out-is only used to distract a predator from a group of squid.

Mating Rituals

Mating rituals, as distinguished from the mating cycle,^[17] constitute my specific area of mayfly squid expertise. Ever since my graduate student days at the University of Florida, I have been fascinated by the mayfly squid’s creativity at courting.

The male squid initiates the mating rituals two or three days before coitus takes place. On the first day, the male squid anchors itself amid the dead leaves and aquatic plants on the lake or river bed. (If, as is often the case, many squid live in close proximity, the male squid may place themselves within a few feet of each other.) Once firmly secured to the bottom, the squid uses its pistolaro and beak to secrete a series of clear bubbles (approximately six centimeters in diameter) that it then gently sticks to its skin using its tentacles. After covering its mantle, head, and arms, the squid will hide its tentacles beneath whatever debris is handy, leaving only its eyes free of bubbles.

The male squid then puts on a kind of light show to attract the female, skillfully manipulating its colors and patterns to shine refracted bioluminescence through the bubbles. From a distance, a bubbled male squid resembles an exotic gemstone with a thousand perfectly cut facets.

Within 24 hours of the male constructing its “bubble tent,” a female squid will appear, circling in the water over the male for several minutes before either investigating further or swimming off into the distance. (At any stage of the mating rituals, up to and including coitus, the female may break off the engagement and swim away.) If the female investigates further, she will first hover directly over the male and then gently rub off the bubbles on its mantle and head. As soon as she does so, the male squid’s light show ends and he begins to pulse a deep, rich green. The female, silver rippling up and down her body, then presses up against the male’s mantle and head, wriggling the fins of her mantle as if to tickle the male squid. Less than a minute later, she places her arms and tentacles over the arms and tentacles of the male.^[18] They both change color to pure silver. This color change concludes the first phase of the mating ritual.