Prey availability often impacts predator survival and reproductive potential. Predatory relationships are fundamental for even the smallest of animals, including rotifers. Cupelopagis vorax (Rotifera; Atrochidae) is a sit-and-wait predator that is unique in its ability to detect vibrations produced by potential prey. Its predatory behavior has been categorized into rotation, encounter, attack, capture, and ingestion. First, capture efficiency of C. vorax was calculated for two prey: the rotifer Lepadella triba (R) and the gastrotrich Lepidodermella squamata (G). Second, we assess how prey type influences the survival and reproduction of C. vorax. In these experiments, the protist Paramecium multimicronucleatum (P) was included to have prey types with distinct sizes, swimming speeds, and structural defenses against predators. Single (R, G, or P) and mixed (RG, RP, GP, and RGP) prey treatments were tested.
Results/Conclusions:
With L. triba as prey, 59.1% ± 0.1 of encounter events resulted in capture and 8.9 ± 1.1 prey were ingested per predator during 4-hr trials (n=15). In comparison, only 32.9% ± 0.04 of encounter events resulted in capture and 5.2 ± 0.86 prey were ingested per predator with L. squamata as the prey species. Using life table analyses, single prey treatments showed that a rotifer (R) diet resulted in longest life expectancies (7.5 ± 1.4 days), and highest net reproductive rates (Ro = 2.5 0.05). In comparison, the protist diet (P) showed the shortest lifespan (4.75 ± 0.5 days) and lowest reproductive rates (Ro = 0.4 ± 0.04) While, the gastrotrich diet (G) resulted in the longest mean generation time (T =5.46 ± 0.10 days). Mixed prey treatments showed that RG and RGP diets showed the highest life expectancies (10.6 ± 1.85 and 9.9 ± 1.29 days, respectively), and highest net reproductive rates (R o= 2.0 ± 0.03 and 1.72 ± 0.04, respectively). Our research shows the importance of capturing beneficial prey and the effects on reproductive and survival parameters. This study will increase our understanding of predator prey relationships within the littoral zone of aquatic communities and phylum Rotifera.