Cidaris

Abstract: Echinoid remains from the Triassic of China are described for the first time. The Middle Triassic of Qingyan in Guizhou Province, south-western China, has yielded nine taxa of primary spines; seven of these come from the lower Upper Anisian. Because all of the spines are disarticulated, the material is treated only parataxonomically. ‘Cidaris’ lineola (Bather) and ‘Cidaris’ wissmanni (Desor) are species originally described from the alpine Triassic of Europe. ‘Cidaris’ bangtoupoensis sp. nov., ‘Cidaris’ wachangpoensis sp. nov., ‘Cidaris’ venustespinosa sp. nov., ‘Cidaris’ fangchui sp. nov., ‘Cidaris’ gu sp. nov., ‘Cidaris’ mafengpoensis sp. nov. and ‘Cidaris’ sp. A are so far known only from Qingyan. Palaeoautecological interpretations based on the shapes of the spines fit well with the fact that the echinoids from Qingyan are part of highly diverse fossil associations which represent the remains of communities that lived in a protected, shallow-marine, stable soft-bottom habitat. The rather high diversity of the echinoid spines in terms of the number of both taxa and general types of shape shows that the echinoids, after nearly becoming extinct at the end of the Palaeozoic, began a new phase of adaptive radiation in the Anisian at the latest.

Abstract: Rock lobsters, Jasus lalandi;, may play an important role in structuring the communities on shallow reef ecosystems and have recently increased in density in the area between Cape Hangklip and Danger Point on the southwest coast of South Africa. This has probably resulted in increased predation on natural poputations of smooth turban shells (Turbo cidaris) and pink-lipped tops hells (Oxystele sinensis), both of which are proposed targets for small-scale commercial fisheries. This study examines the size selectivity, prey species preferences and consumption rates of rock tobsters feeding on these two winkle species. Rock lobsters showed a strong preference for smatt O. sinensis, and were limited to taking a maximum (or critical) size of prey, which increased linearly with rock-lobster size. By contrast, rock lobsters of all size classes tested were able to crack and consume a full size range of T. cidaris, and no size preferences were evident. When the two gastropods were offered simUltaneously, rock lobsters preferentially consumed the thinner shelled O. sinensis. Consumption rates increased linearly with rock-lobster size. Population consumption rates indicale that rock lobsters will have a profound effect on winkle stocks in the area, even if winkles constituted less than 1% of the diet. This in turn suggests that commercial exploitation of these stocks is unlikely to remain sustainable.

Abstract: Of the southern African intertidal and shallow subtidal trochid and turbinid gastropods, Turbo sarmaticus , T. cidaris and Oxystele sinensis , are the most abundant large species, and therefore obvious targets for a winkle fishery. T. sarmaticus is harvested by recreational snorkel divers, and an application has been made for a permit to experimentally harvest the other two species commercially. This study involves four major aspects, namely morphometrics and flesh yield, shore-based abundance estimates, subtidal abundance estimates, and an estimate of the potential yield for each of the three species off the South-Western Cape, South Africa. Abundance and biomass of the winkles increased from west to east, highest densities being recorded in the low intertidal regions to 2 m depth. Low biomasses of the three species were recorded west of Cape Hangklip and are unlikely to support a fishery there. East of Cape Hangklip, invasion of rock lobsters Jasus lalandii has had a considerable impact on T. cidaris and O. sinensis populations. Consequently, a boat-based fishery with an estimated annual total allowable catch of 75.5 tons for T. cidaris , with a bycatch of 9.9 tons for O. sinensis , can only be considered in the easternmost fisheries-management area between Kleinbaai and Quoin Point. Because previous studies on the harvesting potential of T. sarmaticus off the Western Cape concluded that it was not commercially sustainable, a total allowable catch for that species was not considered. Management options deserving considerations before the commencement of a giant winkle fishery are discussed. Keywords: commercial exploitation, Oxystele sinensis , stock assessment, Turbo cidaris , Turbo sarmaticus , yield African Journal of Marine Science 2002, 24: 161–183

Abstract: The Indo-West Pacific genus Garthambrus Ng, 1996, is revised. Two new species are described from New Caledonia and French Polynesia. Lambrus (Parthenopoides) pteromerus Ortmann, 1893, is now transferred to Garthambrus. The genus now consists of 11 nominal species, viz. G. allisoni (Garth, 1992), G. cidaris (Garth and Davie, 1995), G. complanatus (Rathbun, 1906), G. lacunosus (Rathbun, 1906), G. posidon Ng, 1996, G. poupini (Garth, 1992), G. pteromerus (Ortmann, 1892), G. stellatus (Rathbun, 1906), G. tani Ahyong, 2008, G. darthvaderi sp. nov. and G. undulatus sp. nov. Although originally included in Garthambrus, Asterolambrus mironovi Zarenkov, 1990, is herein transferred to a new genus, Hispidolambrus gen nov. Most of these species are known from the West Pacific, but Garthambrus posidon only occurs in the Indian Ocean. Most specimens of Garthambrus have been collected from depths between 81–600 m. The monotypic Caribbean genus Tutankhamen Rathbun, 1925, which closely resembles Garthambrus, is also discussed. Heterocrypta epibranchialis Zarenkov, 1990, has some resemblance to Garthambrus but is here referred to a new genus, Zarenkolambrus, along with a new species, Z. minutus sp. nov.