Influence of the ornamental red cherry shrimp Neocaridina davidi (Bouvier, 1904) on freshwater meiofaunal assemblages

Meiofauna serves as a link between microbial production and higher trophic levels, such as macroinvertebrates and juvenile fish. However, the role of meiofauna in the freshwater food web has not been accurately evaluated, and the influence of shrimp predation on freshwater meiofaunal assemblages is unknown. In this study, the predation effects of Neocaridina davidi, an ornamental freshwater shrimp native to inland water bodies in Asia, on meiofaunal density, biomass, structure, and secondary production were examined using model ecosystems (microcosms) that were sampled repeatedly over 42 days. Shrimp predation altered the structure of the meiofaunal community over the course of the experiment, in particular the density, biomass, and secondary production of nematodes, microcrustaceans, and oligochaetes. An analysis of the stomach contents of N. davidi indicated a high degree of omnivory and the frequent consumption of meiofaunal organisms. The results indicated that predation by the freshwater shrimp N. davidi depresses the overall abundance, biomass, and secondary production of meiofaunal assemblages. Moreover, they also provide insights into food-web ecology and the first evidence of freshwater shrimp predation on meiofaunal assemblages.