Researcher Robert Vrijenhoek, working off the coast of California, discovered a decaying whale colonized by worms called Osedax; but they all appeared to be female worms feeding on the dead whale. As it turns out, the females contain microscopic “sperm packages” which are the males, or at least what they had been reduced to in some evolutionary joke on men. The males are “little sperm factories living off blobs of yolk”. “They just sit there giving sperm to the female until their yolk runs out,” according to Australian researcher Greg Rouse.

“Sexual dimorphism –where males and females exist in different forms – is common in the natural world. In humans, males are just slightly bigger than females. In some angler fish species, on the other hand, the male is comically petite, attaching himself to the female and withering away, leaving only his testes.”

In the case of Osedax, “the males live their whole itty-bitty lives inside the tubes of the females, servicing their reproductive needs in an otherwise thankless existence”. Remind you of any of your married friends?

(National Geographic, The Science of Things: Who Knew? Ladies’ Lunch: It’s strictly the females who line up at this buffet, by Joel Achenbach, February 2005)