Baby Crab Eater – or, a Whiter Shade of Pale

Through the microscope - a baby Red Rock Crab (Cancer productus) measuring less than 1 inch! (photo: E. Loury)
Through the microscope - a baby Red Rock Crab (Cancer productus) measuring less than 1 inch across! (photo: E. Loury)
Erin Loury

by Erin Loury, Ichthyology Lab

These photos come to you straight from the fish gut detective files – and are a diet scientist’s (sadly nerdy) dream come true.  Most of the time, we peer under microscopes to poke and prod at mashed, chewed, digested bits, trying to figure out what animal they once resembled.

Rare are those those idyllic occasions when, behold!  A perfect little specimen appears in your gopher rockfish stomach, as intact as if it had crawled out from under a rock…AND you just so happen to find an identification key from 1921 for tiny  crab specimens under 2 cm.   That is what we in the gut world would consider a “good day.”

The crab snack above was pretty easy to identify.  Cancer productus, the red (yes, red) rock crab is distinctive in its crazy juvenile color patterns, including bright white.  My real triumph as also identifying this widdle guy (Cancer jordani, the hairy rock crab, should you care to know)…

Dime sized - wave hello to baby Cancer jordani, aka gopher rockfish lunch (photo: E. Loury).

The running joke of the diet world is that people who poke at guts become more familiar with the prey species than their predator of study.   Hence, despite being in the ichthyology lab, I will be one crackerjack invertebrate identifier when this is all through, since gopher rockfish love to chow down on all things spineless.  At least, I’ll have the market on identifying 1-inch Cancer crabs cornered!