Feeding the fairy shrimp Streptocephalus (Anostraca - Crustacea) with the rotifer Anuraeopsis

Abstract

Laboratory-cultured Streptocephalus torvicornis were offered 8 concentrations (from 6 to 800 ind. ml⁻¹) of Anuraeopsis fissa for periods of 2 h 30 min. Two size classes, small (male: 14.7 mm± 1.6, female: 15.4 mm± 1.3) and large (male: 20.0 mm±2.0, female: 23.1 mm± 1.5), of S. torvicornis were used. Functional response for large S. torvicornis (both sexes) plateaued at 400 rotifers ml⁻¹, while in small specimens it did so at 200 prey ml⁻¹. Females consumed significantly more (30%) prey than males. Large males consumed maximum 4730 rotifers h⁻¹, females 6560 h⁻¹.