Population structure, feeding and reproductive aspects of Serrapinnus heterodon (Characidae, Cheirodontinae) in a Mogi Guaçu reservoir (SP), upper Paraná River basin

Abstract

Aim: In this report, we describe the population structure, feeding and reproductive aspects of the cheirodontine Serrapinnus heterodon collected in a reservoir of a small hydro power of Mogi Guaçu River (SP); Methods: Specimens were caught bimonthly between August 2005 and July 2006 near the marginal aquatic vegetation with four traps; Results: A total of 38 specimens of S. heterodon were collected (mainly during the rainy season), comprising 16 males (32-47 mm SL), 18 females (32-49 mm SL) and four individuals with indeterminate sex (33-45 mm SL). There were significant differences in length distribution between sexes, with males being smaller than females (_ x males = 42 ± 4.3 mm and _ x females = 45 ± 4.8 mm). Sex ratio was 1:1. Eight food items were identified in the diet, with a predominance of autochthonous items. The diet classified as omnivorous. Insects (fragments) were the most consumed item, followed by microcrustaceans (Cladocera and Ostracoda), algae (mainly diatoms) and immature insects (Diptera and Odonata). Comparing with other cheirodontines, S. heterodon has higher fecundity (mean = 1,231 ± 440 oocytes) and smaller oocytes (61 to 793 µm). Moreover, the spawning was classified as total and occurred during the rainy season which is the breeding season for the majority of fish species from the upper Paraná River basin; Conclusions: The results seem to reflect the type of environment in which S. heterodon inhabit, because the lentic environment afforded by the dam provides relatively stable conditions to maintaining this species, which uses aquatic vegetation as shelter from predators and as feeding and breeding sites.

Feeding ecology of Serrapinnus notomelas (Characiformes: Cheirodontinae) in small forest streams in the Machado River basin, Rondônia, Brazil

“…In studies involving Serrapinnus heterodon in a reservoir in the São Paulo state (Gonçalves et al 2011) and S. notomelas on a lake in the Paraná River basin (Carniatto et al 2012), it was found a high frequency of full stomachs, our study corroborate those findings. In fishes, the seasonal cycle of nutritional reserves, such as fat, follows a pattern associated with reproduction (Favero et al 2010;Freitas et al 2011;Espírito-Santo et al 2013), when fishes reduce feeding activity and use the energy stored in fat for gonadal maturation (Santos et al 2010).…”

“…Based on tooth morphology, Malabarba (2003) classified Cheirodontinae species mainly as herbivores. This classification was confirmed by the high value of intestinal quotient (0.62 mm) observed by Gonçalves et al (2011) for S. heterodon. Hahn and Loureiro-Crippa (2006) and Luiz et al (1998) studied lagoons and streams in the Paraná river catchment basin and classified S. notomelas as an algivorous species, while Minzão et al (2004) classified it as omnivorous because of its consumption of microcrustaceans and algae.…”

“…Over 1500 Characiformes species have been described to date . Although the subfamily Cheirodontinae is one of the best-known groups of Characidae in terms of phylogeny and taxonomy (Malabarba 2003;Bührnheim et al 2008), there is a dearth of studies on the ecology of this subfamily (Benitez and Súarez 2009), and most of the available information is on the biological aspects of Cheirodontinae species in southern Brazil (Santi-Rampazzo et al 2008;Benitez and Súarez 2009;Gonçalves et al 2011). (Eigenmann, 1915) shows ornamental importance (Regulatory Directive 001/2012-MPA/MMA) and contributes 0.0009% of the total ornamental fish exports of Brazilian inland waters caught in the states of Amazonas and Pará (IBAMA 2008).…”

Flood pulse are the main determinant of feeding dynamics and composition of Odontostilbe pequira (Characiformes: Characidae) in southern Pantanal, Brazil

“…As a result of the wide distribution of Cheirodontinae species in the main Neotropical hydrographic basins, studies about aspects of their ecology are numerous, including feeding (Luiz et al, 1998;Hirano & Azevedo, 2007;Dias & Fialho, 2009), population structure (Benitez & Súarez, 2009;Gonçalves et al, 2011;Tondato et al, 2012), reproductive ecology (Silvano et al, 2003;Azevedo et al, 2010;Tondato et al, 2014) and their effect on zooplankton density (Roche et al, 1993;Fantin-Cruz et al, 2008). However, in the Pantanal, the few existing studies did not focus on Cheirodontinae species, and are mixed with other groups (Ximenes et al, 2011).…”

Physical habitat simulation for small-sized characid fish species from tropical rivers in Brazil

“…Based on the L50, the total length ranged from 2.05 cm to 4.2 cm for individuals of Astyanax sp. congeneric species, from 4.1 cm to 4.5 cm for P. stramineus, from 2.79 cm to 3.75 cm to P. argentea and higher than 3.2 cm for S. hetero don (Gomiero et al, 2007;Castro et al, 2010;Gonçalves et al, 2011;Lourenço et al, 2015).…”