Life on the Leg of a Crab

Spider Crab feasts on the remains of a fish (Depth: 2229 m) Observation : 7282, 2012-06-15 00:07:11UTC, 1564. N47°55.9909′, W129°5.9243′ Credit: NEPTUNE Canada/CSSF

Neptune Canada, the world’s first regional-scale underwater ocean observatory network that plugs directly into the Internet, has an excellent Flickr photostream of deep-sea beasties.

A close up on the legs on the crab above reveals something amazing.

Close-up view of a crab feasting on fish (Depth: 2229 m) Observation : 7282, 2012-06-15 00:07:11UTC, dive 1564. N47°55.9909′ W129°5.9243′ Credit: NEPTUNE Canada/CSSF

Do you see it? Let me help.

What you see attached to the legs of the crab are skeleton or ghosts shrimps (there is actually a three, the third is just left of the upper red box). Ghost shrimps are not actually shrimps (in a group we call the Caridea) but rather in a group called the Caprellidae.  In fact they are not even in the same order (Decapoda vs. Amphipoda).  Caprellids are only found in the oceans and have a special pair of appendages for attaching to things like kelp, seagrass, small children swimming, or crab’s legs.  Although a few species filter feed particles out of the water.  Some are sit and wait predators patiently awaiting for another animal or really small child to get too close.  THEN BAM! A SMALL INVERTEBRATES MEETS ITS MAKER!

From Wikimedia Commons: Caprella mutica Schurin, 1935 Morphology (Male) Japanese skeleton shrimp.

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