Demographic responses of Heterocypris incongruens (Ostracoda) related to stress factors of competition, predation and food

Abstract

<em>Heterocypris incongruens</em> is a widely distributed ostracod which can maintain its populations under stressful conditions such as those in temporary ponds and under low-quality diets, for example, detritus. It often co-occurs with cladocerans and fish living in shallow water bodies. Nevertheless, little is known about its response to the presence of predators, its consumption capacity of cyanobacteria typically present in eutrophic systems, and its interaction with other species in similar habits. We studied here the demographic responses of <em>H. incongruens</em> fed the green alga <em>Scenedesmus</em> <em>acutus</em>, two strains of <em>Microcystis </em>cf. <em>aeruginosa</em> and <em>Limnothrix</em> sp. Experiments were conducted separately and together in the presence of the cladoceran <em>Simocephalus vetulus </em>and the cichlid fish, <em>Oreochromis</em> kairomones. The ostracod maintained growth in all treatments, the reproductive output decreased on dietary <em>Limnothrix </em>sp., and its life expectancy was significantly lower with the toxic strain of <em>Microcystis</em>. The coexistence of both crustacean species increased the rate of population growth (~ 0.33 day<sup>-1</sup>) of <em>S. vetulus</em> and life expectancy (36-44 days) of <em>H. incongruens</em> on the test diets compared with controls (23-33 days). Our study suggests facilitation affects the interaction between the two microcrustaceans, especially on poor quality cyanobacterial diets.

First report of ostracods (Crustacea) associated with Bithynian (Anisian, Middle Triassic) Tubiphytes‐microbial reef in the North Dobrogean Orogen (Romania)

“…) leading to reduced survival and increased reproduction rates (Fernández et al . ). Ongoing work of the first author documents abundant ostracods in association with benthic microbial communities growing as red, gelatinous deposits (known as kopara or opara; e.g.…”

Population growth of microcrustaceans in water from habitats with differing salinities

“…However, if these factors influenced the results, it did not happen equally in both water types. Another possibility is that the presence of another species is facilitating the population growth of the ostracods, which was shown in Heterocypris incongruens when grown with a cladoceran ( Fernandez et al, 2016 ).…”