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Two introduced beachfleas,Orchestia gammarellusandPlatorchestia platensis, have been recorded from South Africa, but have been misidentified by some earlier researchers and, prior to this study, each was also known from just a few, scattered observations, such that their true distributions remained obscure. We illustrate both species to clarify the features that identify and distinguish them and determine their true distributions by re-examining historical samples and by collecting new material from estuaries and lagoons along the west and south coasts of South Africa. Adult males ofO. gammarellushave slender antennae and characteristic expanded, flattened, oar-like distal segments on pereopod 7. Adult males ofP. platensishave the peduncle of antenna 2 strongly swollen and have bulbous, but not flattened, distal segments on pereopod 7. Both species occur under wrack and other debris along the banks of estuaries and sheltered lagoons.Orchestia gammarellusis found only along the south-west coast, in the Berg River Estuary, Langebaan Lagoon and the Diep River Estuary. Previous records from Knysna were misidentifications ofP. platensis.Platorchestia platensisis found at one west coast site, Langebaan Lagoon, but is widely distributed from Cape Point eastwards to at least Algoa Bay. Both species share the same habitats as several other native beachfleas and competitive interactions between native and introduced species merit investigation. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to document recent additions to the South African barnacle (Cirripedia) fauna. New species records were obtained by examining accumulated collections of unidentified material in the Iziko South African Museum, as well as via material collected directly by the authors. Fourteen species, none of which are new to science, are added to the known fauna, raising the total number of barnacle species recorded from South Africa by over 20%, from 69 to 83 species. Ten of the additional species are offshore benthic forms and represent deep-water taxa whose ranges are extended into South African waters. The remaining four are coastal inshore or surface-dwelling species, of which three are considered recent anthropogenic introductions. The large number of additions to the fauna can be attributed to a long absence of taxonomic expertise on this group in the region and consequent accumulation of unidentified samples. A high proportion of the deep-water samples examined contained previously unreported species, suggesting that additional sampling of hard abyssal substrata in the region is certain to yield yet more new cirripede records. [ABSTRACT FROM AUTHOR]

This study documents the fauna associated with two common comatulid crinoid species, Comanthus wahlbergi and Tropiometra carlnata, in False Bay, South Africa, and describes the patterns of infestation of obligate associate species. A total of 11 invertebrate species was found associated with one or both crinoids. Of these, three were considered obligate: the myzostomidans, Myzostoma fuscomaculatum and Myzostoma n. sp., and the shrimp, Hippolyte catagrapha, all of which only occurred on T. carinata. Both frequency and density of infestation were higher for the two myzostomes than for the shrimp. The majority of crinoids infested with myzostomes hosted two or more individuals, while H. catagrapha usually occurred singly. A total of 67.5% of all T. carinata collected were infested by symbionts. Of these 45% hosted only one species, 17% hosted two species and 5.8% hosted all three. Most M. fuscomaculatum (85.2%) and H. catagrapha (82.1%) matched their hosts' colouring, while Myzostoma n. sp. were all yellowish in colour. Infestation by Myzostoma n. sp. increased in both frequency and density with depth. All three obligate symbiont species are new to science, illustrating the biodiversity that can still be uncovered by investigating new niches. [ABSTRACT FROM AUTHOR]

A revised and updated list of South African sea anemones is compiled and the distribution pattern and endemicity of each determined from museum and literature records. Forty-nine valid species are recognized. Species richness appears fairly uniform around the coast, although marked peaks occur at Cape Town, False Bay and Durban - almost certainly the result of disproportionately intense sampling effort at these locations. Forty-nine percent of species are endemic, slightly above the average for the South African marine fauna (31%), but well within the range shown by component taxa. Endemics are absent in the northwest, hut otherwise comprise a fairly consistent proportion of species in each region. The fact that existing records are strongly biased towards a few centres of high sampling activity, indicates a pressing need for additional systematic collection of this group in under-represented areas. [ABSTRACT FROM AUTHOR]