The Ascidians of the Reef Flats of Fiji PATRICIA KOTT KoTT. P.. The ascidians of the reef flats of Fiji. Proc. Linn. Soc. N.S. W. 105 (3), (1980) 1981: 147-212 This first account of the ascidians of Fiji is based on collections from the fringing reefs of Viti Levu, the island of Yakuve, and the Great Astrolabe Reef. Records confirm the wide range of the Indo-west Pacific ascidian fauna. Many species parameters are newly defined and scanning electron microscopy has contributed to the definition of species in the family Didemnidae that comprise half of the sixty species recorded. Five new species are described. Patricia Kott (Dr P. Mather), Queensland Museum, Brisbane, Australia 4006; manuscript received IJuly 1980, accepted in revised form 22 April 1981. Introduction The collections on which this report is based are principally from the fringing reefs along the southern and eastern coasts of Viti Levu, the main island of Fiji, and from Yakuve and the Great Astrolabe Reef. Fiji has not previously been surveyed for this group of organisms. Most of the species recorded are from cryptic habitats under stones and boulders, and in crevices in the reef flat, but algal -bearing species (Kott, 1980) have been taken from the open reef flat. The cryptic species comprise a relatively small proportion of the reef flat ascidian biomass, being far outnumbered by the prolific algae-bearing didemnid species. Deeper subtidal habitats have not been sampled. The records confirm the wide geographical range of species in the tropical Indo-west Pacific (Kott, 1974, 1980) and only very few species are endemic to Fiji. For many of the species these records constitute the first since they were originally taken by the Siboga Expedition in 1900 (Sluiter, 1904, 1909). This report refers only briefly to the 13 species of plant cell-bearing Didemnidae that occur prolifically in Fiji, but have been discussed more fully by Kott (1980). Didemnum molle, Lissoclinum patellum, Trididemnum strigosum and T. nubilum are newly recorded from Fiji. There are five new species described. This does not necessarily reflect a high degree of endemism in the Fijian fauna. It is an indication of the extent to which the ascidian fauna of the Indo-west Pacific region is not understood and the parameters of species not defined. Scanning electron microscopy of spicules has contributed to the definition of species in the family Didemnidae, to which 34 of the 60 species recorded belong. The following abbreviations are used in the account that follows: AMNH, American Museum of Natural History; BM, British Museum (Natural History) ; QM, Queensland Museum ; ZMA, Zoological Museum of Amsterdam. Where colours of the living specimens have been matched with standards from Ridgeway (1886) they are stated in quotation marks. Systematic Descriptions Order APLOUSOBRANCHIA Family HOLOZOIDAE Proc. Linn. Soc. N.S.W., 105 (3), (1980) 1981
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