About Zebrida adamsii White, 1847
Zebrida adamsii is a small species of crab. When it was first discovered by English naturalist Arthur Adams and Scottish zoologist Adam White during the HMS Samarang surveying voyage through the Far East between 1843 and 1846, Adams described it as "a torpid, though elegant little crustacean". This species has smooth, hairless carapaces and limbs that are decorated with long spines. Individuals are pink with dark reddish-brown vertical stripes. Zebrida adamsii has a wide distribution across shallow tropical waters of the Indian Ocean and western Pacific Ocean. Its type locality is the estuary of the Pantai River in Borneo, at a depth of approximately 11 meters (35 feet). Zebrida adamsii lives in symbiosis with sea urchins, residing among the urchins' spines. It has been recorded living on the following sea urchin species: Asthenosoma ijimai, Diadema setosum, Heliocidaris crassispina, Pseudocentrotus depressus, Salmacis bicolor, Salmacis virgulata, Toxopneustes elegans, Toxopneustes pileolus, Tripneustes gratilla, and an undescribed species of Acanthocidaris. This species has specific adaptations for its symbiotic lifestyle: a specialized joint between the propodus and dactylus on its walking legs lets it cling tightly to its host, and its vertical striped pattern provides cryptic colouring. Female Zebrida adamsii are slightly larger than males; females usually live alone on a single sea urchin, while males move between different urchins searching for females. Zebrida adamsii feeds on its host's tube feet, as well as the epidermal tissue covering the host's test and the base of its spines. This feeding causes little harm to the host sea urchin, which can readily regenerate both the damaged tissue and tube feet. The larvae of Zebrida adamsii are planktonic. They go through four zoeal stages and one megalopa stage before settling on the seabed and undergoing metamorphosis into juvenile crabs.
