The Sea Mouse

“Hey, wait! What the heck?” This is what you may be saying after yesterday’s post, which featured an unlabeled picture of a mystery sea creature (above).

Well worry no more! The mysterious creature is a “sea mouse”, the colloquial name for a genus of polychaete worms which live in the Atlantic Ocean (and the Mediterranean Sea).  The proper genus name for the sea mouses (mice?) is Aphrodita, after the Greek goddess of love (apparently some exceedingly lonely 18^th century taxonomists thought the furry oval sea animal with a ventral groove along its bottom resembled the sacred goddess of sexuality in some generative aspect).

Sea mouses (mice?) are scavengers which feed on the decaying bodies of marine animals [probably: a few sources thought they were hunters].  They live close to shore in the intertidal zone where they creep and burrow as they try to find carrion and avoid predators. To my mind, their English name is vastly better than their scientific name since they scurry furtively across the ocean bottom and since they are covered in what superficially looks like scraggly hair.  This “hair” is more properly called setae—bristles which protect the worm and or help it to hide or communicate.  The setae around the edges of the mice are covered with photonic crystals so they look drab from most angles but sparkle like gorgeous blue/green/gold opals when held a certain way.

Speaking of bristles, sea mice move by means of parapodia—bristly appendages which serve as feet and which also look somewhat like hair. The creatures measure from 7–15 centimeters (3–6 inches) long; however, some giants can grow to a length of 30 centimeters (12 inches).

The febrile imaginings of long dead natural scientists aside, sea mice (mouses?) are all hermaphrodites with both male and female gonads and sexual organs [probably…different sources disagreed upon their gender orientation, and given today’s social mores, it was thought impolite to inquire].  The worms are incapable of fertilizing themselves though.

Of course, some of you might still have some questions about this living technicolor hermaphroditic toupee which crawls around on the ocean bottom eating horrible dead things, but I can help you no further.  My limited knowledge of sea mice is all used up.  They aren’t even mollusks (they are more closely related to…well to us…than to clams and squid). Based on the many bracketed addenda and the numerous weasel words in this article, our understanding of these things is pretty superficial. If you want to make a name for yourself in marine biology this may be your chance, provided you can spend a lifetime underwater watching polychaete worms eat and make love!