Disease in Sea Urchins

Abstract Sea urchin diseases occur both in the field and in culture. A variety of diseases of sea urchins have been found, over a wide range of geographical areas and involving many species of both regular and irregular sea urchins. Disease agents ranging from bacteria to decapods, but particularly bacteria and parasites, are known to affect sea urchins. Ecological factors usually play a role in inducing diseases. ‘Bald sea urchin disease’ and some other diseases with typical lesions are common in the field. Bacteria have been considered to be the major agent of this kind of disease, which occur after abrasions made by mechanical injury or ectoparasite. It has been suggested that the bacteria involved in the worldwide disease commonly called the bald sea urchin disease are opportunistic and not specific. There is growing interest in the culture of sea urchins worldwide. Infectious diseases causing devastating mariculture failure and great economic loss have been a common problem. Diseases in cultured sea urchins, mainly Strongylocentrotus intermedius , are described here in detail. Disease of bathyal spatangoids in culture is also described.