Critter of the Week: No reason to be grumpy at Easter!

For many of us there are lots of reasons to be cheerful around Easter, what with long weekends and chocolate galore. Despite this, however, grumpy crabs still seem grumpy.

The NIWA Invertebrate Collection wishes everyone a happy Easter break with our version of an Easter bunny, the sponge crab Dromia wilsoni.

As McLay (1988) puts it, “a shaggy covering of dark khaki hairs covers the entire animal”. Often, this species covers itself with a piece of sponge or sea squirt.

Dromia wilsoni is a widespread species originally described from Victoria, Australia; it is known to occur from the subtidal region to 520 metres depth off South Africa, New Zealand, Japan and the little island Dr. Helena (southern Atlantic Ocean).

Whenever experts see these wide distributions, questions are usually raised as to whether it is a single species. Hopefully, one day someone will be able to examine representatives from across its proposed range and establish whether it is indeed one or more species.

Easter bunny in disguise! Dromia wilsoni from the Bay of Islands, around 145 metres depth. The body is about 2 cm across. Credit: Peter Marriott NIWA/ Ocean Survey 20/20 Bay of Islands Coastal Biodiversity, Sediment and Seabed Habitat Project.