The Holothurian fauna of Southern Africa.

Abstract

The last thorough revision of the southern African holothurian fauna appeared in 1948 and since then there have been numerous additions to the fauna . A comprehensive revision of the fauna is here undertaken on the basis of currently accepted changes in classification and nomenclature. The survey is based on the collections of the South African Museum and of the Universities of Cape Town and Durban-Westville. The material comprises some 2768 specimens distributed over six orders and 72 species. Another 48 species, excluding the two pelagic forms, are included to complete the survey. The about 95 species recorded from this region prior to this investigation are tabulated in chronological sequence of their descriptions and/or records. The new taxa diagnosed include eight genera, one subgenus, 12 species and one subspecies. There are in addition 15 new records and 15 new synonyms. A checklist to all species known to date is included and keys reconstructed. Full descriptions of new species and those formerly inadequately described are given. The diagnoses of some others are modified and/or additional notes added. The zoogeographical distribution of the fauna, based on our current knowledge of ocean currents and their effects along the coast, is discussed and the following four faunal provinces recognised: tropical, subtropical, warm temperate and cold temperate. The relationship; of the Dactylochirotida and Dendrochirotida is discussed. The inclusion of the Rhopalodinidae in the Dactylochirotida is questioned and so is also the status of the cucumariid subfamily Colochirinae. It is concluded that the southern African holothurian fauna is of largely Indo-Pacific origin with most of the endemic component probably representing cold water tolerants of former Indo-Pacific species. The Atlantic Ocean region has played a very small but significant role in the development of the fauna, while the contribution of the Southern Ocean and Antarctic regions is negligible.