Cannibalism by the invasive invertebrate zooplanktivore Bythotrephes cederstromii Schodler, 1863 (Cladocera: Cercopagidae)

Cannibalism (i.e., intraspecific predation) affects the population dynamics of many invertebrate species. Cannibalism by the predatory cladoceran Bythotrephes cederstromii Schodler, 1863 has been observed and noted in laboratory settings on several occasions, but no studies have published results of cannibalism experiments or explicitly quantified Bythotrephes cannibalism rates. We performed two laboratory experiments that demonstrated and quantified Bythotrephes cannibalism. Cannibalism occurred frequently in our experiments, and cannibalism clearance rates were comparable to those for Bythotrephes feeding on heterospecific prey. Further, our estimates of clearance rates between conspecifics suggest that cannibalism could be an important food source during certain periods of the year, and in particular places, for which Bythotrephes densities are at the higher end of observed ranges. While more research is needed, our results suggest that there are conditions in which cannibalism should be included in models of Bythotrephes predation, including bioenergetics models predicting Bythotrephes consumption rates.

Automated summary

This passage discusses the study of cannibalism in Bythotrephes cederstromii, demonstrating and quantifying the cannibalism rates through laboratory experiments. The results suggest that cannibalism could be an important food source during certain periods of the year and in particular places.