Effect of starvation time on the prey capture behaviour, functional response and population growth of Asplanchna sieboldi (Rotifera)

Abstract

1. We examined the effect of different periods of prior starvation(from 30 min to 16 h) on the prey capture behaviour, and functional and numerical responses of the predatory rotifer Asplanchna sieboldi using the rotifer Brachionus calyciflorus as prey. 2. Feeding activity (i.e. encounter, attack, capture and ingestion) by Asplanchna increased significantly with increasing prey densities from 2 to 16 mL−−1 and with increasing prior starvation periods from 0.5 to 8 h. 3. Asplanchna sieboldi showed a type II functional response at all the prior starvation periods tested. The asymptotic prey density was highest after 8 h of starvation. 4. The instantaneous population growth rate of A. sieboldi ranged from 0.089 ± 0.044 (when starved for 8 h in every 24 h and at a prey density of 2 individuals mL−−1 for the other 16 h) to 1.015 ± 0.142 in the control (no starvation and at a prey density of 16 individuals mL−−1). The effect of starvation time on the numerical response was evident only at the higher prey density.

Small prey size offers immunity to predation: a case study on two species of Asplanchna and three brachionid prey (Rotifera)

“…Numerous works have shown that prey consumption increases with increasing prey density until a level beyond which an asymptote is evident (Nandini & Sarma, 1999;Nandini et al, 2003). In our study too, we obtained this trend.…”

“…For example, high-population growth rates such as in B. calyciflorus (Sagrario, 2003), are effective, as has been shown in various taxa (Abrams & Walters, 1996). Since Asplanchna shows both numerical and functional responses, an increase in prey availability leads to increased consumption and increased predator density (Nandini & Sarma, 1999). However, Asplanchna shows density-dependent male and resting egg production which results in decreased population density (King & Snell, 1980) and this alleviates predation pressure.…”

Morphological and Morphometrical Variations of Selected Rotifer Species in Response to Predation: a Seasonal Study of Selected Brachionid Species from Lake Xochimilco (Mexico)

“…The efficacy of spines, setae and movement patterns in avoiding predation has been well documented in laboratory experiments on predator feeding behaviour, functional response and numerical response (Sarma, 1993;Nandini & Sarma, 1999). Gilbert (1999) has reviewed the role of asplanchnin produced by Asplanchna, which induces elongation of lorica spines in some members of Brachionidae.…”

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

“…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).…”