Dental development and ontogenetic diet shifts of Roeboides paranensis Pignalberi (Osteichthyes, Characinae) in pools of the Upper Rio Paraná floodplain (State of Paraná, Brazil)

Abstract

Species of the characid genus Roeboides are known for their habit of tearing off and ingesting scales from other fishes. Specimens of Roeboides paranensis were taken monthly from March 1992 through February 1993 in five pools of the upper Rio Paraná floodplain and in one site in the Rio Paraná itself, with the aim of relating the dental development to ontogenetic diet shifts. Between 15-22 mm SL, fish had teeth with hypertrophied bases (mammiform) that moved to the outside of the mouth in both maxillas. During ontogeny, the diet shifted, with the smallest individuals eating more microcrustaceans and the larger ones eating more scales. Lepidophagy is non-obligatory, because the ingestion of insects and other invertebrates occurred at all sizes. Spatial variation in diet was large, however diet similarity was great for Roeboides from three floodplain pools that had similar proportions of the main diet categories.

Influência do ciclo hidrológico na dieta e estrutura trófica da ictiofauna do Rio Cuiabá, Pantanal Mato-Grossense

“…No rio São Francisco, esta categoria trófica foi a mais representativa em abundância numérica e biomassa (ALVIM & PERET, 2004). Apesar dos dentes exteriorizados adaptados para arrancar escamas, as duas espécies de Roeboides, reconhecidas como predominantemente lepidófagas (SAZIMA & MACHADO, 1982;HAHN et al, 2000;NOVAKOWSKI et al, 2004), apresentaram variação na dieta independente do ambiente considerado, consumindo, em alguns casos, uma quantidade maior de invertebrados aquáticos e pedaços de peixes do que de escamas.…”

Temporal and ontogenetic variations in feeding habits of Hollandichthys multifasciatus (Teleostei: Characidae) in coastal Atlantic rainforest streams, southern Brazil

“…Diet shift related to ontogenetic variations have been the object of broad discussion in the literature (Nikolsky, 1963;Machado-Allison & Garcia, 1986;Winemiller, 1989;Gerking, 1994;Hahn et al, 2000). According to Lowe-McConnell (1999), in tropical environments, the majority of fish species show broad flexibility in feeding habits, which seems to be related to morphological (e.g., mouth gap) and behavioral (e.g., locomotion ability) changes during development (Wooton, 1999).…”

Diet shifts related to body size of the pirambeba Serrasalmus brandtii Lütken, 1875 (Osteichthyes, Serrasalminae) in the Cajuru Reservoir, São Francisco River Basin, Brazil

“…Ontogenetic diet shifts have been demonstrated for piscivorous (Machado-Allison & Garcia, 1986;Nico & Taphorn, 1988;Winemiller, 1989) and scaleeating (Hahn et al, 2000) tropical fish. Early life stages of these fishes commonly present a diet based on microcrustaceans and insects.…”