Diet of four annual killifishes: an intra and interspecific comparison

LAUFER, G., ARIM, M., LOUREIRO, M., PIÑEIRO-GUERRA, J. M., CLAVIJO-BAQUET, S., FAGUNDEZ, C.

NEOTROPICAL ICHTHYOLOGY

SOC BRASILEIRA ICTIOLOGIA

Lugar: Porto Alegre; Año: 2009 vol. 7 p. 77 - 86

1679-6225

We examined the diet of 4 annual fishes, Austrolebias viarius, Austrolebias cheradophilus, Austrolebias luteoflammulatusand Cynopoecilus melanotaenia inhabiting temporal ponds of southeastern Uruguay, by analysis of stomach contents.Fishes were captured from fifty ephemeral ponds of Castillos Lagoon basin, in the region of the Humedales del Este. Weidentified 13099 individual prey items extracted from 669 stomachs of the four captured species. In the studied system, annualkillifishes represents the most abundant and conspicuous top predators. Killifishes are generalist key predators at the ephemeralponds of the studied system, consuming mostly aquatic items. Zooplancton represented the bulk of the diet in the fouranalyzed species, followed by eggs, algae and diatoms. Insects are the next group in prey number, as follows: Diptera larvae(especially Chironomidae and Cullicidae), Ephemeroptera (especially Betidae), and coleopteran larvae (especially Dytiscidae).Acari are also important prey in number. The four fish species differ in diet composition and in diet richness. A general patternof differences in diet richness among killifish species and demographic groups could be related to variations in body sizes. Astop predators annual killifishes are an important component of the temporal pond ecosystems. Understanding the naturalhistory of this species and their communities is necessary in order to conserve them.