This little crab was found by Mairangi Bay School near their MM2 survey area on the rocky shore at Mairangi Bay Beach, Auckland. It is about 10mm in width, its body looks just like Neptune's Necklace seaweed. It was hiding under a piece of plant material.
It's a pillbox crab Halicarcinus sp. It has quite chunky legs, often the species I see have very fine legs!
The Marine Metre Squared website, mm2.net.nz, is a citizen-science project and is owned and managed by the NZ Marine Studies Centre, University of Otago. Content is licensed under the Creative Commons Attribution-NonCommercial–ShareAlike license, unless otherwise stated.