Dierckens, K.R., Beladjal, L., Vandenberge, J., Swings, J., Mertens, J.-1997
Journal of Crustacean Biology, 17 (2) : 264-268
Abstract:
Streptocephalus torvicornis and Branchipus schaefferi, males and females separately, were fed Escherichia coli at densities ranging from 1 x 10^6 to 5.5 x 10^7/ml. These shrimps are able to consume large quantities of E. coli. Branchipus schaefferi consumed 4 x 10^8 E. coli/ind/hr and S. torvicornis consumed 5 x 10^8 E. coli/ind/hr (0.082 mg/hr/ind). Consumption leveled at an initial density of 4 x 10^7 E. coli/ml/ for B. schaefferi, while for S. torvicornis consumption leveled at 4.5 x 10^7 E. coli/ind/hr.
The functional response curves of these filter feeding shrimps showed an unexpected pattern. For the males of both species, at 15 x 10^6 E. coli/ml there was a small decrease in consumption, while the curves of the females showed a similar decrease at 20 x 10^6 E. coli/ml. This phenomenon is explained by assuming that the distance between the setae of the limbs, the movement rate of the thoracic appendages, or the inclination of the filtering apparatus is altered.
During 5 h experiments, both species do not feed at a constant rate.
(State Univ Gent, Ecol lab, K.L. Ledeganckstr 35, B-9000 Gent, Belgium)
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