The effect of prey morphology on the feeding behaviour and population growth of the predatory rotifer Asplanchna sieboldi: a case study using five species of Brachionus (Rotifera)

Abstract

Summary 1. We investigated the numerical response, functional response and prey preference of Asplanchna sieboldi to five different prey brachionids. We also analysed the feeding behaviour of the predator in terms of encounters, attacks, capture and prey ingested per unit time. 2. The five prey species (Brachionus havanaensis, B. rubens, B. patulus, B. macracanthus and B. calyciflorus) differed in their body size and spine length. 3. The population growth rates of A. sieboldi ranged from 0.074 ± 0.03 to 0.431 ± 0.02 depending on prey type and density. There was a significant impact of the spine length rather than body size per se on the population growth rates of the predator. 4. The maximum number of prey consumed depended on both body size and spine length. In the functional response analyses, the plateau was reached at a prey density of 4–8 ind. mL−1. 5. There was a significant impact of prey density on the prey preference of the predator.

Inducible defenses and rotifer food chain dynamics

“…The effects of prey vulnerability on the functional response and growth have been tested for Asplanchna preying on B. calyciflorus and several other rotifer species (Iyer & Rao, 1996;Nandini et al, 2003). The capture success and ingestion of Asplanchna on spined B. calyciflorus is much lower than on non-spined B. calyciflorus (Iyer & Rao, 1996).…”

Effects of predation by Hydra (Cnidaria) on cladocerans (Crustacea: Cladocera)

“…in our study Macrothrix showed the highest probability of being killed after an encounter with Hydra (K/e=0.84). it has been observed that prey species with elongated spines such as Brachionus havanaensis and Brachionus macracanthus offer protection against predation by the predatory rotifer Asplanchna because it cannot ingest them (Nandini et al, 2003). in this work, Macrothrix was easily ingested by Hydra, probably because cnidarians possess flexible tissues so that the spines of the prey do not damage them (anderson, 2001).…”

Combined effects of temperature and prey (Brachionus angularis) density on life-table demography and population growth ofAsplanchna brightwelli(Rotifera)

“…The r values in population growth studies of A. sieboldi Leydig fed B. havanaensis, B. rubens Ehrenberg, B. patulus Muller, B. macracanthus Jakubski or B. calyciflorus and A. brightwelli fed B. calyciflorus or A. fissa increased with increasing prey density (Sarma et al, 1998(Sarma et al, , 2002bNandini et al, 2003). Similarly, in the present study, at 28 xC, the population growth rate of A. brightwelli increased with increasing B. angularis density.…”

“…Most herbivorous rotifers usually have r values about 0.5 day x1 (Sarma et al, 2001), but carnivorous genus may have r values higher than 0.5 up to 1.5 day x1 . The r values of A. girodi ranged from 0.09 to 1.51 day x1 (Dumont and Sarma, 1995;Sarma et al, 2003), and those of A. sieboldi ranged from 0.07 to 0.43 day x1 (Sarma et al, 2002a;Nandini et al, 2003). A. brightwelli had r values of 0.22-1.01 day x1 (Sarma et al, 1998).…”

“…Much literature is available on the food and feeding habits of Asplanchna, both from field and laboratory studies (reviewed in Dumont, 1977;Pourriot, 1977;Williamson, 1983;Arndt, 1993;Sarma, 1993;Conde-Porcuna and Sarma, 1995;Iyer and Rao, 1996;Nandini and Sarma, 1999;Nandini et al, 2003;Sarma et al, 2011). Although there are some data on the life-table demography and the population growth rate of Asplanchna as a function of prey levels (e.g., Urabe, 1992;Dumont and Sarma, 1995;Conde-Porcuna and Declerck, 1998;Sarma et al, 1998Sarma et al, , 2002aSarma et al, , 2003Sarma, 1999, 2000;Nandini et al, 2003), the combined effects of temperature and the prey level are inadequately studied (Verdone-Smith and Enesco, 1982).…”