What’s the News: In the squid world, the body size of male spear squid determines the mating strategies they use. Small male squid, which have no chance of physically competing with their larger rivals, must try to get with the females of the species on the sly. Now, researchers in Tokyo have learned that this difference in mating behavior has resulted in the evolution of divergent sperm types, though perhaps not in the way you’d think: diminutive male squid actually produce larger sperm than big male squid.

What’s the Context:

Male spear squid, also known as Bleeker’s squid, are either large “consorts,” or small “sneakers.” During mating, consorts will try to court a female by flashing vibrant colors across their bodies; if successful, a consort will place a packet of sperm, called a spermatophore, into the female’s oviduct, a tube that leads to her ovaries. As you’d expect from his title, the consort male will then guard his ...