A new species of Tortanus (Atortus)(Copepoda: Calanoida: Tortanidae) from Rodrigues Island, Mauritius

A new species of the copepod genus Tortanus (Atortus) (Copepoda: Calanoida), T. (A.) insularis, is described from the coastal region of Rodrigues Island, Mauritius, an isolated island in the south-western Indian Ocean. This new species can be assigned to an Indian element, the recticauda species group, in the Indo-West Pacific recticauda species complex. It exhibits the closest relationship to T. (A.) recticauda recorded from the southern Red Sea and Arabian Gulf, rather than the more closely distributed T. (A.) capensis, recorded from off South Africa.

Aspects Of Gametogenesis In The Marine Mussel Mytilus-Edulis-L

Marine bivalve molluscs have in recent years attracted considerable attention for a variety of reasons, not least of which is their importance as a source of food for man. Much of this research has concentrated on studies of reproduction; Mytilus viridis (India: Nagabhushanam & Mane, 1975), M. edulis aoteanus and Aulacomya maoriana (New Zealand: Kennedy, 1977);Choromytilus meridionalis and Aulacomya ater (South Africa: Berry, 1978); Mytilus (= Perna) perna (Brazil: Lunetta, 1969); M. edulis planulatus (Australia: Wilson & Hodgkin, 1967); Mytilus californianus and M. edulis (U.S.A.: Hines, 1979); Mytilus galloprovincialis (France: Lubet, 1959) and M. edulis (U.K.: Chipperfield, 1953; Seed, 1975; Bayne et al. 1978). A review of the literature revealed that in the majority of studies cytology was used as a descriptive tool for the ‘staging’ (Chipperfield, 1953; Lubet, 1957; Seed, 1975, 1976) of the developing gametes and certain anomalies were apparent with regard to the nomenclature of the connective tissue matrix of the mantle lobes.

Pattern of benthic biomass size spectra from shallow waters in the East China Seas

Benthic biomass size spectra (BSS) and normalized biomass size spectra were constructed, and benthic secondary production was estimated by a size spectrum equation in the shallow waters in the East China Sea, ranging latitudinally from 40A degrees N to 29A degrees N. The BSS patterns were bimodal, two biomass peaks corresponding to meiofauna and macrofauna, respectively, separated by a trough of low biomass at 8-256 mu g individual dry weight which varied in position with median sediment particle size. The BSS also displayed bimodality within meiofauna size ranges, which in most stations was due to the relative proportions of nematodes and other meiofauna taxa. Re-analysis of data from sites in the UK, South Africa, and Antarctic showed a similar bimodality in the adult species body size distribution within the meiofauna size range. Macrofaunal production estimated by the size spectrum equation was very similar to the results of Brey90 empirical equation. However, these production values were much lower than those calculated by Brey01. Different individual dry-to-wet conversion ratios, temperature deviation, and macrofauna taxonomic composition might be responsible for the between-model differences. The macrofaunal P/B ratios calculated by this equation ranged from 0.3 to 3.4 which were in accordance with values from Northern Hemisphere mid-latitudes. Meiofaunal production estimates will need further empirical support.