The Peculiar Mating Habits of Squid

Birds do it. Bees do it. Even educated fleas do it, the Cole Porter song goes. But there's nary a mention of the giant squid. Well, the mammoth mollusks do it too -- but in their own peculiar way, according to a report by Mark D. Norman and C.C. Lu, of the University of Melbourne in Australia, in the Oct. 16 issue of Nature.

A female giant squid captured off the southern Australia coast had sperm embedded in her arms, the researchers report. That indicates that male partners, which grow to lengths of 45 feet, use their nearly three-foot-long "muscular" appendages to stab females and deposit sperm in the wound, "potentially under hydraulic pressure," the researchers said.

Females may store the sperm for long periods because "encounters with male giant squid are infrequent in these dark depths" where the tentacled creatures live, some 1,500 to 3,000 feet below the ocean surface. When they're ready to fertilize their eggs, females may somehow "peel open" the skin covering the sperm, or perhaps "the sperm may migrate to the surface on hormonal or chemical cues," the researchers write. "Alternatively, the female's skin might degrade on spawning, exposing the embedded sperm stores."

Curiously, a male giant squid caught off Norway in the 1950s had sperm embedded in its skin. "Another male may have injected" the sperm "while attempting to impregnate a female, accidentally `riveting' a co-suitor," the researchers write. "Alternatively, the male may have literally `shot' himself in the foot."