[2] Goneplax rhomboides is a relatively small (carapace up to 3.7 cm or 1.5 in in diameter), distinctive-looking crab that ranges from yellowish-white, to orange, to reddish to vivid pink in colour.

[5] G. rhomboides has often been confused with G. clevai, a similar species sharing at least part of its range.

[6] Waters off Shetland constitute the northern boundary of its range, and in 2008, marine biologists from the University of Gothenburg discovered one intact in the stomach of a cod caught off the coast of Bohuslän which suggests that G. rhomboides has now moved into Swedish waters.

[9] The setae on the antennae, mouthparts and legs of G. rhomboides are home to Triticella flava, a species of Bryozoa ("moss animal").

[9] The short lifespan of these symbiotic moss animals is synchronized so that they produce larvae just before G. rhomboides moults.