The Shallow water bryozoans of the West Coast of South Africa

Abstract

The South African biota is characterised by high levels of diversity and endemism. While commercially viable taxa have been well-studied, cryptic organisms such as bryozoans, have been neglected in terms of study. Taxonomic research on the South African Bryozoa has a brief and fragmented history. As a consequence most of the previous studies have focused on the south and east coasts of South Africa, and at depths deeper than 100 m. It is suggested that previous studies of the Bryozoa in South Africa have failed to reveal more than a fraction of the potential faunal complexity for this region. Earlier studies of the South African bryozoan fauna have described -255 species, mainly from the south and east coasts. The current study, therefore, attempts to identify and describe the shallow water bryozoan fauna from the west coast of South Africa and to compare the South African fauna with that of other regions. Specimens collected from localities, ranging from False Bay to Port Nolloth, along the west coast of South Africa, yielded 63 species, representing three orders (Cyclostomata, Ctenostomata and Cheilostomata), 32 families and 46 genera. Five species are cyclostomes, three are ctenostomes and 55 are cheilostomes. The ratio between the orders is not surprising considering the relatively low diversity of Cyclostomes and Ctenostomes in marine habitats. Thirteen species are new to science (-21% of the total species described in this study), of which seven species are found in seven genera (Eurystrotos, Klugeflustra, Thalamoporella, Bitectipora, Schizosmittina, Fenestrulina and Celleporina) that are newly reported from South Africa and thirteen species are reported from the west coast for the first time, of which one, Hippomonavella formosa, is a new record for South Africa. Including the species described here, approximately 269 valid species, representing three orders (Cyclostomata, Ctenostomata and Cheilostomata), 73 families, and 130 genera have been reported from South Africa. An accurate species number is not yet possible from this area as there are still outstanding problems with synonymies.