Differences in effects of grazing by deposit-feeders Hydrobia ulvae (Pennant) (Gastropoda : Prosobranchia) and Corophium arenarium Crawford (Amphipoda) on sediment microalgal populations. I. Qualitative differences
Morrisey, D.J. (1988). Differences in effects of grazing by deposit-feeders Hydrobia ulvae (Pennant) (Gastropoda : Prosobranchia) and Corophium arenarium Crawford (Amphipoda) on sediment microalgal populations. I. Qualitative differences. J. Exp. Mar. Biol. Ecol. 118(1): 33-42. https://dx.doi.org/10.1016/0022-0981(88)90120-7
In: Journal of Experimental Marine Biology and Ecology. Elsevier: New York. ISSN 0022-0981; e-ISSN 1879-1697, more
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| Keywords |
Corophium arenarium Crawford, 1937 [WoRMS]; Hydrobia ulvae (Pennant, 1777) [WoRMS]
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| Author keywords |
Choice test; Deposit-feeder; Grazer; Microalga |
| Abstract |
Earlier studies have shown that, despite the similarity of their diets, the presence of the amphipod Corophium arenarium Crawford has no negative effect on the growth rate of the prosobranch Hydrobia ulvae (Pennant), and that the former species is capable of removing a larger portion of the sediment microflora. In the present study, qualitative differences in the effects of grazing by the two species, in terms of alteration of the attractiveness of sediment by pregrazing, were investigated. In choice tests, it was found that, although Corophium would discriminate against sediment grazed by its own species in favour of ungrazed sediment, it did not similarly discriminate against Hydrobia-gtazed sediment. This latter choice was in favour of sediment containing significantly lower numbers of microalgae, implying that grazing by the snail left behind a sufficient and suitable fraction of the microflora to attract Corophium. Hydrobia discriminated against sediment grazed by either species. It is, therefore, suggested that the dietary range of the amphipod, at least when deposit-feeding, is generally broader than, and includes, that of the snail. Further evidence, however, suggests that part of the dietary spectrum of Hydrobia may lie outside that of Corophium. |
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