Monthly Archives: June 2015

Zebrida is a small genus of distinctive striped crabs, known as zebra crabs, that live in association with sea urchins in the Indo-Pacific.

Zebrida was described by Arthur Adams as “a torpid, though elegant little crustacean”. It is “the most unusual” of the genera in the subfamily Eumedoninae, with long spines projecting from the body, and a distinctive pattern of stripes across the exoskeleton.

The genus was thought to be monotypic for a long time, but in 1999, Peter Ng & Diana Chia recognised two additional species, bringing the total number to three.

Zebrida adamsii is widespread in the Indian Ocean and western Pacific Ocean, from Japan to Australia.
Zebrida brevicarinata is only known from Western Australia.
Zebrida longispina is only known from Western Australia.

Crabs of the genus Zebrida live, often in pairs, in association with sea urchins, including Toxopneustes pileolus, Toxopneustes elegans, Tripneustes gratilla, Diadema setosum, Asthenosoma ijimai, Salmacis bicolor, Salmacis virgulata, Heliocidaris crassispina, Pseudocentrotus depressus and a species of Acanthocidaris.

Z. adamsii passes through four zoeal phases, and one megalopa phase before reaching the mature condition.

Adam's Urchin Crab, Indonesia

If you like this, then please use Twitter, Google+ & FaceBook to inform your friends about this topic.

Pelicans are a genus of large water birds that makes up the family Pelecanidae. They are characterised by a long beak and a large throat pouch used for catching prey and draining water from the scooped up contents before swallowing. They have predominantly pale plumage, the exceptions being the brown and Peruvian pelicans. The bills, pouches and bare facial skin of all species become brightly coloured before the breeding season. The eight living pelican species have a patchy global distribution, ranging latitudinally from the tropics to the temperate zone, though they are absent from interior South America as well as from polar regions and the open ocean.

Long thought to be related to frigatebirds, cormorants, tropicbirds, gannets and boobies, pelicans instead are now known to be most closely related to the shoebill and hamerkop, and are placed in the order Pelecaniformes. Ibises, spoonbills and herons are more distant relatives, and have been classified in the same order. Fossil evidence of pelicans dates back to at least 30 million years to the remains of a beak very similar to that of modern species recovered from Oligocene strata in France. They are thought to have evolved in the Old World and spread into the Americas; this is reflected in the relationships within the genus as the eight species divide into Old World and New World lineages.

Pelicans frequent inland and coastal waters where they feed principally on fish, catching them at or near the water surface. They are gregarious birds, travelling in flocks, hunting cooperatively and breeding colonially. Four white-plumaged species tend to nest on the ground, and four brown or grey-plumaged species nest mainly in trees. The relationship between pelicans and people has often been contentious. The birds have been persecuted because of their perceived competition with commercial and recreational fishing. They have suffered from habitat destruction, disturbance and environmental pollution, and three species are of conservation concern. They also have a long history of cultural significance in mythology, and in Christian and heraldic iconography.

A Pair of Pelicans

If you like this, then please use Twitter, Google+ & FaceBook to inform your friends about this topic.