Effect of zooplankton type and abundance on prey consumption by the fairy shrimp, Streptocephalus proboscideus (Anostraca: Crustacea)
Por:
Jawahar Ali A., Sarma S.S.S., Murugan G., Dumont H.J.
Publicada:
1 ene 1996
Resumen:
Laboratory cultured Streptocephalus proboscideus (three sizes (mm), viz. 8.44 ± 0.95 (virgin), 14.18 ± 1.49 (adult I) and 19.24 ± 1.52 (adult II)) were offered (separately for males and females) field collected zooplankton (12 prey types) at three levels of abundance (1.0 ml-1, 2.0 ml-1 and 4.1 ind. ml-1 in 30-minute feeding experiments. Gut contents, analyzed for abundance and diversity of prey type, showed that predator size, sex and their interaction had strong effects on prey consumption. Regardless of their size, and of prey density, S. proboscideus females consumed 25-90% more prey than males. Their filtration rates (adult II) were higher (125 ml ind.-1 h.-1) than those of males (30 ml ind.-1 h.-1) too. Rotifers had the highest numerical percentage in the gut, regardless of predator size or sex. Cladocerans were only consumed by adults I and II. Adult II females consumed 28.5-43.3 ?g zooplankton dry weight ind.-1 h.-1. Size distribution of B. longirostris in the field and in the gut were closely similar. This study confirms S. proboscideus as a non-selective filter feeder. Since it did not eat jumping rotifers, copepod nauplii and copepodites, it may contribute to structuring its prey communities, because good escapers will be enriched in the medium, while poor escapers will be depleted. © 1996 Kluwer Academic Publishers.
Filiaciones:
Jawahar Ali A.:
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, Gent, B-9000, Belgium
Sarma S.S.S.:
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, Gent, B-9000, Belgium
Murugan G.:
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, Gent, B-9000, Belgium
Dumont H.J.:
Laboratory of Animal Ecology, University of Ghent, K. L. Ledeganckstraat 35, Gent, B-9000, Belgium
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