The genus Boccardia (Polychaeta: Spionidae) associated with mollusc shells on the south coast of South Africa
- Authors: Simon, Carol A , Worsfold, T M , Lange, Louise , Sterley, Jessica A
- Date: 2010
- Language: English
- Type: text , Article
- Identifier: vital:6873 , http://hdl.handle.net/10962/d1011620 , http://dx.doi.org/10.1017/S0025315409990452
- Description: Three species of Boccardia (B. polybranchia, B. pseudonatrix and B. proboscidea) were associated with mollusc shells on the south and south-east coasts of South Africa. Boccardia polybranchia was widely distributed along the coast and falls within the known distribution range of this species. Comparisons with material from other, international, locations showed that some specimens have been misidentified. No characters could be found to characterize distinct species for different regions within the range of B. polybranchia, as currently recognized. Boccardia pseudonatrix was found only at the most eastern site, increasing its known distribution range. Boccardia proboscidea, a non-indigenous species, was found only on abalone farms and was most abundant in the west.
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- Date Issued: 2010
Physical and biological processes at the Subtropical Convergence in the South-west Indian Ocean
- Authors: Froneman, P William , Ansorge, Isabelle J , Richoux, Nicole B , Blake, Justin , Daly, Ryan , Sterley, Jessica A , Mostert, Bruce P , Heyns, Elodie R , Sheppard, Jill N , Kuyper, B , Hart, N , George, C , Howard, J , Mustafa, E , Pey, F , Lutjeharms, Johan R E
- Date: 2007
- Language: English
- Type: Article
- Identifier: vital:6966 , http://hdl.handle.net/10962/d1012030
- Description: A detailed hydrographic and biological survey was conducted in the region of the Subtropical Convergence in the Indian sector of the Southern Ocean in April 2007. Hydrographic data revealed that the subsurface expression of the Subtropical Convergence (at 200 m), marked by the 10°C isotherm, appeared to meander considerably between 41°S and 42°15’S. Total surface chlorophyll- a concentration was low and ranged from 0.03 to 0.42 µg l–1 and was always dominated by the pico- (<2 µm) and nano- (2–120 µm) size classes, which contributed between 81% and 93% of the total pigment. The total chlorophyll-a integrated over the top 150m of the water column showed no distinct spatial trends, and ranged from 12.8 to 40.1mg chl-a m–2. There were no significant correlations between the total integrated chlorophyll- a concentration and temperature and salinity (P > 0.05). The zooplankton community was dominated, numerically and by biomass, by mesozooplankton comprising mainly copepods of the genera, Oithona,Paraeuchaeta, Pleuromamma, Calanus and Clausocalanus. An exception was recorded at those stations in the region of the front where the tunicate, Salpa thompsoni, dominated the total zooplankton biomass.
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- Date Issued: 2007