Heterocypris incongruens (Ramdohr, 1808)’in seksüel popülasyonunun insan yapımı bir gölette (Kahramanmaraş, Türkiye) rapor edilmesi ve Heterocypris Claus, 1892 cinsinin hemipenislerinin karşılaştırılması

Abstract The Axolotl, Ambystoma mexicanum, endemic to the freshwater lakes, Xochimilco and Chalco in Mexico City, feeds on zooplankton during its larval stages. We evaluated the functional response over eight weeks of A. mexicanum fed different prey items found in its natural habitat (rotifers: Brachionus havanaensis, B. calyciflorus, B. rubens and Plationus patulus; cladocerans: Moina macrocopa, Macrothrix triserialis, Alona glabra and Simocephalus vetulus; and ostracods: Heterocypris incongruens). Zooplankton consumption by A. mexicanum varied in relation to the prey species and age of the larvae. Unlike oviparous fish larvae which often feed preferentially on rotifers in the first few weeks, A. mexicanum larvae fed more on cladocerans and ostracods. Among the cladocerans offered, larval A. mexicanum consumed higher numbers of M. triserialis and M. macrocopa. Feeding on the largest cladoceran tested, S. vetulus, increased after the fifth week. There was a consistent increase in the number of ostracods Heterocypris incongruens, consumed with age, from 4 to 169 prey per larva over eight weeks. The results are discussed with relation to the importance of zooplankton diet in conservation effort of this endangered species in Lake Xochimilco.

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

Journal of Limnology ◽

10.4081/jlimnol.2016.1367 ◽

2016 ◽

Vol 75 (s1) ◽

Cited By ~ 2

Author(s):

Rocio Fernandez ◽

Sarma Nandini ◽

S.S.S. Nandini ◽

Maria E. Castellanos-Páez

Keyword(s):

Life Expectancy ◽

Population Growth ◽

Reproductive Output ◽

Cichlid Fish ◽

Poor Quality ◽

Stress Factors ◽

Temporary Ponds ◽

Crustacean Species ◽

Heterocypris Incongruens ◽

Demographic Responses

Heterocypris incongruens 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 H. incongruens fed the green alga Scenedesmus acutus, two strains of Microcystis cf. aeruginosa and Limnothrix sp. Experiments were conducted separately and together in the presence of the cladoceran Simocephalus vetulus and the cichlid ﬁsh, Oreochromis kairomones. The ostracod maintained growth in all treatments, the reproductive output decreased on dietary Limnothrix sp., and its life expectancy was significantly lower with the toxic strain of Microcystis. The coexistence of both crustacean species increased the rate of population growth (~ 0.33 day-1) of S. vetulus and life expectancy (36-44 days) of H. incongruens 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.

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