Diet and ecomorphology of Leporinus reticulatus (Characiformes: Anostomidae) from the upper Rio Juruena, MT, Brazil: ontogenetic shifts related to the feeding ecology

Abstract

The conservation of diverse and well-distributed fish taxa, as the genus Leporinus, relies intrinsically on the knowledge of the ecological attributes of its representatives. Aiming to increase this knowledge, studies on diet and ecomorphology are ideal to provide important information about species ecology. Thus, this study aimed to analyze aspects of feeding ecology of L. reticulatus, from the upper Rio Juruena, Mato Grosso State, Brazil. The diet of specimens in different ontogenetic stages was compared, as well as their teeth morphology and ecomorphological attributes. Leporinus reticulatus presented omnivorous diet, with higher consumption of invertebrates by smaller specimens (younger ones), and gradual introduction of plant items in larger specimens (older ones). The items consumed by the individuals and the ecomorphological attributes indicated that the species is generalist and opportunistic, besides its association with the river bottom, evidencing a benthic feeding behavior. This species presents a gradual ontogenetic modification in teeth shape and mouth positioning, ranging from a terminal mouth with tricuspid teeth, in smaller specimens, to an inferior mouth with spatula shaped teeth with no cusps, in larger specimens. The ecomorphological attributes indicate an increasing swimming efficiency, and ability for performing vertical displacements, along the ontogenetic development, which in addition to the morphological ontogenetic alterations in the buccal apparatus, contributes to a better ability to explore another niches. KEYWORDS: Neotropical ichthyofauna, freshwater fish, trophic ecology, ontogenetic morphological variation. Dieta e ecomorfologia de Leporinus reticulatus (Characiformes: Anostomidae) do alto Rio Juruena, MT, Brasil: alterações ontogenéticas relacionadas à ecologia alimentar RESUMO A conservação de táxons de peixes de grande diversidade e amplamente distribuídos, como o gênero Leporinus, depende intrinsicamente do conhecimento de atributos ecológicos de seus representantes. Objetivando o aumento deste conhecimento, estudos que abordam a dieta e a ecomorfologia são ideais para prover informações importantes sobre a ecologia de espécies. Assim, este trabalho teve como objetivo analisar aspectos da ecologia alimentar de L. reticulatus originários do alto Rio Juruena, estado do Mato Grosso, Brasil. Foi comparada a dieta de espécimes em diferentes estágios ontogenéticos, assim como a morfologia dos dentes e atributos ecomorfológicos. Leporinus reticulatus apresentou dieta onívora, com maior consumo de invertebrados pelos espécimes de menor porte (mais jovens), e introdução gradual de itens vegetais por espécimes de maior porte (mais velhos). Os itens consumidos pelos indivíduos e os atributos ecomorfológicos indicaram que esta espécie é generalista e oportunista, além de sua associação com o fundo do rio, evidenciando um comportamento alimentar bentônico. Esta espécie apresenta modificação ontogenética gradual no formato dos dentes e posição da boca, variando de uma boca termina...

Different developmental environments reveal multitrait plastic responses in South American Anostomidae fish

“…Therefore, Anostomidae fish constitutes a promising model to address the role of developmental plasticity for phenotypic diversification (Sidlauskas, 2008). Our results suggest that different configurations of developmental environments might contribute to phenotypic diversification in Megaleporinus fish (Machado-Evangelista et al, 2015;Sidlauskas & Vari, 2008). Given the morphological and behavioral transformations in larval and juvenile forms of M. macrocephalus during ontogeny, developmental environments may not only comprise selective pressures, but also constitute factors that induce phenotypic variation (see Laland et al, 2015;Lehman & Stanley, 2013;Pigliucci, 2008;Schlichting, 2008).…”

“…We use Megaleporinus macrocephalus fish (Anostomidae, Characiformes), an ideal system to explore these questions due to its suitability for experimental manipulation in the lab (Barbosa, Alves, Fim Pereira, Ide, & Hoffmann, ; Wolkers, Barbosa Junior, Menescal‐De‐Oliveira, & Hoffmann, ) and also because developmental plasticity remains unknown for this species. Fish from this genus are distributed along South and Central America (Garavello & Britski, ; Machado‐Evangelista, EsguÍcero, Arcifa, & Pereira, ), and Anostomidae species tend to exhibit remarkable changes in the positioning of the buccal apparatus during ontogeny (Sidlauskas & Vari, ). The genus Megaleporinus (formerly known as Leporinus ) comprises omnivorous species that mainly explore benthic habitats and throughout their ontogeny undergo a series of morphological changes, culminating in the ability to explore a wide range of niches.…”

Morphological development of larvae and juveniles of Prochilodus argenteus

“…Ontogenetic shifts in the habitat use are usually associated to changes in the morphometric proportions of structures related to feeding, swimming speed and movement maneuverability such as mouth position and gap size, the position of unpaired and paired fins and its development degree (ABELHA et al, 2001;MACHADO-EVANGELISTA et al 2016). This seems to be the case of P. argenteus and possibly of other Prochilodus species that change from a zooplanktophagous to an iliophagous feeding habit with the concomitant change from a pelagic to a benthonic behavior.…”

Efeito da seca e da variação espacial na abundí­¢ncia de indiví­­duos nas guildas tróficas da ictiofauna em um reservatório no Semiárido Brasileiro

“…Nos meses em que houve precipitação, o recurso vegetal estava disponível em maior quantidade, assim, os herbívoros puderam maximizar o consumo desse item, o que influenciou o aumento da abundância das espécies componentes da guilda. Isso pode ser explicado pelo comportamento oportunista e pela morfologia das espécies que compõem a guilda, características essas que propiciam a utilização dos recursos mais abundantes no ambiente (MACHADO-EVANGELISTA et al, 2015). Assim, as oscilações do nível da água causam modificações na abundância e variedade de recursos alimentares, que influenciam a composição e o número de indivíduos nessa guilda.…”