Dietary–morphological relationships in a fish assemblage of the Bolivian Amazonian floodplain

Abstract

Morphological correlates of diet were examined in 48 species of freshwater fishes from floodplain lakes in the central part of the Mamore´River (Bolivian Amazon). The species were classified, according to the percentage occurrence of seven food items, into eight broad trophic categories: mud feeders, algivores, herbivores, terrestrial invertivores and omnivores, carnivores, zooplanktivores, aquatic invertivores and piscivores. There were significant relationships between the diet and morphology of the fishes even when the effect of taxonomical relatedness between species was eliminated. Relative gut length was the main morphological variable used to order species on a carnivore to mud feeder gradient. Standard length and head and mouth size were the morphological variables most closely associated with prey size. Mud feeder, algivore and piscivore species appeared as the most dietary and morphologically specialized. These results support both the hypotheses that species morphology influences the diet and that morphological similarity is conserved even in comparison with taxonomically unrelated species.

Dietary-morphological relationships in fish assemblages of small forested streams in the Bolivian Amazon

“…The morphological variables were selected based on previous works by Gatz (1979); Watson and Balon (1984); Winemmiller (1991); Kramer and Bryant (1995); Hugueny and Pouilly (1999) and Pouilly et al (2003). Six ecomorphological variables were measured on 5 to 70 individuals for each species, depending on the number of individuals captured (Table 2).…”

“…carla.lunallena@gmail.com;oberdorf@mnhn.fr Winemiller et al 1995;Piet 1998;Hugueny and Pouilly 1999;Xie et al 2001;Elliott and Bellwood 2003;Pouilly et al 2003). For instance, in fishes, gut length clearly distinguish algivores, detritivores and herbivores from carnivores (Paugy 1994;Kramer and Bryant 1995;Delariva and Agostinho 2001;Ward-Campbell et al 2005).…”

“…However, only a few studies have attempted to control for evolutionary distance between species. For instance, Hugueny and Pouilly (1999) and Pouilly et al (2003) assessed how their results were affected by taxonomic relatedness (as a surrogate of phylogenetic distances) of the species compared. In both cases, when taxonomic relatedness was factored out, relationships between diet and morphology were still significant.…”

Ecomorphology and use of food resources: inter- and intraspecific relationships of fish fauna associated with macrophyte stands

“…On the other hand, since fish diets are diverse (using all available food resources in the environment), it is reasonable to question whether there are general patterns of use of prey and whether these patterns are related to the diversity of feeding mechanisms (Wainwright, 1999). In this context, correlation between morphological attributes and diet has been tested in ecomorphological hypotheses in fish assemblages (Pouilly et al, 2003).…”

Ecomorphological differences between Rhamdia (Bleeker, 1858) populations from the Iguaçu River basin

“…Ecomorphological indices were calculated using data obtained from linear measures and areas. The indices and their respective formulae were adopted according to previous studies (Gosline 1971, Gatz Jr. 1979, Watson & Balon 1984, Wikramanayake 1990, Norton & Brainerd 1993, Casatti & Castro 1998, Pouilly et al 2003, Breda et al 2005 3. Data analysis.…”