A small spider crab, Naxia tumida can be found on rocky coasts amongst algae, or under rocks. To camouflage itself, this species will snip off pieces of algae, which it attaches to its carapace with an adhesive substance, making it difficult to see identifying features. Its teardrop shaped carapace is rimmed with spines, with the shape and location of these useful for identifying this species. To the non-expert, the easiest way to distinguish this species from the more common Naxia aurita is its more bumpy carapace, which is usually brownish instead of yellow and without the distinctive black spots of that species.
