Your Moment Of Squid

Elizabeth Preston shines a spotlight on the badass, gender-bending opalescent inshore squid:

Scientists have found that certain female squid can switch on and off a body pattern that makes them look male. They use a never-before-seen cell type to do it, and it may be all for the sake of keeping the actual testes owners far away. …. Daniel DeMartini, a graduate student at the University of California, Santa Barbara, “observed the female squid rapidly switching the stripe on and off,” says his advisor, Daniel Morse. He decided to gather a few hundred D. opalescens squid in laboratory tanks and watch them work. DeMartini found that females can turn on a bright white stripe on their mantles, highlighted by a line of iridescence on both sides. This happens to look pretty similar to a male squid’s testis, which—in his less colorful moments—is visible as a long white shape inside his transparent body.

She adds, “The authors speculate that female squid might use this stripe as a disguise when they want to avoid harassment by males”:

“In this species of squid, mating occurs in dense assemblages of animals, with the females subject to repeated bouts of mating by multiple males,” Morse says. By switching on her white stripe and mimicking a male, a lady squid might be able to fend off some of these mating attempts, protecting both herself and any fertilized eggs she’s carrying.

(Photo of a Doryteuthis opalescens paralarva via Wikipedia)