Known introduced / cryptogenic ascidians species on the South African coastline :

1. Species / Sites Alexander Saldanha Table Mossel Knysna Port Bushman's Port East Durban Bay Bay Bay Bay Elizabeth River Alfred Lond on Clavelina √ √√ √√ √√ √ √√ lepadiformis √√√ √√√ √√√ √√√ √√√ √√√ √√√ √√√ Diplosoma listerianum √ √ √√ Corella eumyota √√√ √√√ √√√ √ √ √ Ciona intestinalis √√√ Ascidiella aspersa √√√ √√√ √ Botryllus schlosseri √√ √√ √ Cnemidocarpa humilis √√ Ascidia sydneiensis √√√ Styela canopus √√ √√√ √√ √√ Styela plicata √ √√ √√√ √√√ √√√ √√√ Microcosmus squamiger Introduced ascidians along the coast of South Africa: water temperature as a predictor of their geographical distributionMarc Rius1, Charles L. Griffiths2, Xavier Turon11Departament de Biologia Animal, Universitat de Barcelona, Av. Diagonal 645, 08028, Barcelona, Spain2Department of Zoology, University of Cape Town, Rondebosh, Cape Town 7700, South Africa Known introduced / cryptogenic ascidians species on the South African coastline: Introduced: Clavelina lepadiformis, Diplosoma listerianum, Ciona intestinalis, Ascidia sydneiensis, Ascidiella aspersa, Botrylloides leachi, Cnemidocarpa humilis, Styela plicata, Microcosmus squamiger Cryptogenic:Trididemnum cerebriforme, Didemnum granulatum, Didemnum psammathodes, Didemnum rodriguesi, Corella eumyota, Botryllus schlosseri, Polycarpa insulsa, Styela canopus Surveys in winter 2007 covering all main harbours, marinas and an oyster farm SOUTH AFRICA Benguela Current Agulhas Current ATLANTIC OCEAN INDIAN OCEAN Cape Agulhas: where the Indian and Atlantic Oceans meet Cape Agulhas Survey sites √ - Rare √√ - Common √√√ - Dominant Tolerant to a wide temperature range √ Dominant in cold waters Dominant in warm waters Cross fertilization For C. intestinalis and A. aspersa(following Havenhand & Svane 1991) and for S. plicata and M. squamiger(Marshall & Keough 2003) • Larval development (within 24 hours) depending on the temperature (N = 5 individuals) • Four dominant species : • West of the Cape (C. intestinalis, A. aspersa) • East (S. plicata, M. squamiger) Settlement patterns followed the same trend according to temperature