Mutilating predation in the Cheirodontinae Odontostilbe pequira (Characiformes: Characidae)

Abstract

We observed individuals of Odontostilbe pequira, a small characid, approaching and biting individuals of larger-bodied fishes of other species. This observation was made in two clear water headwater streams of the Cuiabá basin, Paraguay River system, located in Nobres, Mato Grosso State, Brazil, which led us to investigate the behavioral interactions of these fish. We characterized behavioral interactions between species by direct underwater observations using snorkelling and video recordings. Additionally, we proceeded diet analyses of O. pequira, obtaining intestinal coefficient and the index of alimentary importance. During underwater observations we checked the relative frequency of attacks by O. pequira on larger fish species. Odontostilbe pequira attacked individually or in large groups, and the anostomid Leporinus friderici was the preferred target prey species, while Prochilodus lineatus was apparently avoided. Our study sustains that O. pequira is omnivorous, with a diet that varies seasonally. It feeds mainly on plants, but also on animal prey, including the scales of small fishes, and, possibly, the mucus and epidermis of larger fish species. We suggest the term "mutilating predation" to describe the latter relationship.Observamos indivíduos de Odontostilbe pequira, um caracídeo pequeno, abordando e mordendo peixes maiores de outras espécies. Essa observação foi feita em dois riachos de cabeceira com águas cristalinas na bacia do rio Cuiabá, sistema do rio Paraguai, localizados em Nobres, Mato Grosso, Brasil, o que nos levou a investigar a interação comportamental desses peixes. Nós o fizemos através de observações subaquáticas diretas usando mergulho livre e vídeo. Adicionalmente, realizamos a análise da dieta de O. pequira, obtendo seu coeficiente intestinal e índice de importância alimentar. Nas observações subaquáticas avaliamos a frequência relativa dos ataques de O. pequira sobre peixes maiores. Odontostilbe pequira ataca individualmente ou em grupos grandes, o anostomídeo Leporinus friderici foi a presa preferida, enquanto Prochilodus lineatus foi evitado. Este estudo sustenta que O. pequira é um peixe onívoro cuja dieta varia sazonalmente. Ele come principalmente plantas, mas também presas animais, como escamas de peixes pequenos e, possivelmente, muco e epiderme de peixes maiores. Sugerimos o termo "predação mutilante" para descrever essa relação.

Unrevealing Parasitic Trophic Interactions—A Molecular Approach for Fluid-Feeding Fishes

“…In other examples, Lima et al (2012) reports a behavior of "mutilating predation" for Odontostilbe pequira preferentially attacking Leporinus friderici, but do not show any support as molecular identification of food items. Based only in field observations of the putative attack, O. pequira is currently classified as omnivore.…”

“…DNA barcode techniques have been used to determine host-parasitoids webs in arthropods (Hrček and Godfray, 2014), as in Lepidoptera (Janzen et al, 2009) and Hemiptera (Gordon and Weirauch, 2015). However, in fish species the establishment of parasitic interaction has been reported as difficult (Sazima, 1983;Lima et al, 2012). According to Paine (1980) "The central significance of webs is derived from the fact that the links between species are often easily identified and the resultant trophic scaffolding provides a tempting descriptor of community structure."…”

Resource use by the facultative lepidophage Roeboides affinis (Günther, 1868): a comparison of size classes, seasons and environment types related to impoundment

“…On the other hand, behavioral studies alone might also lead to equivocal conclusions (e.g. Lima et al, 2012). Species belonging to several trophic guilds were reported to consume scales in the upper Tocantins River (Albrecht, 2005).…”

Occasional release of guppy, Poecilia reticulata (Cyprinodontiformes, Poeciliidae) in Upper Paraguay River Basin, Mato Grosso State: a new threat to rivers forming the Brazilian Pantanal?

“…Especially when we consider the studies by Krinski et al (2015) reporting that 31 species of native fish can be found in Tangará da Serra streams, and 330 species in the upper Paraguay River basin (Reis et al, 2013). Although studies show that even small native fish can present a variety of feeding behaviors that may or may not affect the larger fish composition (Lima et al, 2012;Krinski, 2010).…”