Ontogenetic diet shifts and diet overlap among three closely related neotropical armoured catfishes

Abstract

Analysis of stomach contents of larvae, juveniles and adults of three closely related armoured catfishes in coastal plain swamps of Suriname, South America, revealed major ontogenetic diet shifts. Larvae or Hoplosternurn littorule. H. thorucntum and CuNicktliJ;.~ culliclithys showed a restricted diet of rotifers and microcrustacea. Diets of juveniles and adults werc more diverse, but large volumes of microcrustacea, aquatic insect larvae and detritus were always present. In all three species dict overlap was especially low between larvae and adults. The proportion of detritus in the stomach was positively related to fish size, which probably reflected the inability of larger size classes L o separate etrectively benthic invertebrate prey from bottom substrata, and not a specialization towards detritivory. Adults showed only minor seasonality in diet composition. and no effect of season on diet breadth. Interspecific diet overlap among larvae, juveniles and adults did not differ significantly from 1 (complete overlap). Lack of food partitioning was probably related to a similar morphology of the three catfishes. Intraspecific between-size class diet overlap was considerably lower than interspecific within-sizc class overlap. It is suggested that large interspecific diet overlap occurred because food was not limiting the populations of these catfish. However, the nest habitats of the three species ditfered.( ' 1995 The Fi.;hrrics Society of the British Isle5

Diet of Iheringichthys labrosus (Pimelodidae, Siluriformes) in the Itaipu Reservoir, Paraná River, Brazil-Paraguay

“…The relative abundance of drifting taxa and benthic invertebrates also showed variation among seasons in a temperate stream (Angermeier, 1982). However, other benthophagous species (callichthyids) showed little differences in the diet (aquatic insects and detritus) among seasons (Mol, 1995). This might be a result of the ample amounts of available benthic invertebrates.…”

Annotated list and key to the stream fishes of Trinidad & Tobago

“…Native. Spawns in the wet season (Ponton & de Mérona 1998), males build a bubble nest at the water surface from mucous and vegetation (Mol 1995). Omnivore .…”

Uso do alimento por duas espécies simpátricas de Moenkhausia (Characiformes, Characidae) em um riacho da Região Centro-Oeste do Brasil

“…Espécies filogeneticamente relacionadas tendem a ser ecologicamente mais semelhantes em muitos aspectos. Consequentemente, a coexistência entre elas é difícil de explicar (MOL, 1995). Entretanto, CHASE & LEIBOLD (2003) argumentam que, em pequenas escalas, espécies relacionadas que coexistem em comunidades geralmente exibem algum tipo de diferenciação (temporal ou espacial) na ocupação de micro-hábitats, na dieta ou em outros fatores.…”