Piscivory by Hoplias aff. malabaricus (Bloch, 1794): a question of prey availability?

Abstract

Index). Spearman correlation analysis, a glm and CCA were performed between biotic and abiotic variables, and we used the CPUE as a measure of fish abundance. Results: Eleven taxa of fish were recorded, four of which were predated by adult "trahira". Insects and other items were also common in the stomachs of juveniles. According to statistical analysis, it was observed that the highest consumption of cichlids was correlated with its increase in CPUE in the environment, while no relationship was observed for A. bimaculatus, C. bimaculatum and S. notonota abundances. The environmental factors as nutrients, transparency and water volumn were related to selection of species by trahira. Conclusions: Intrinsic characteristics of preys as swimming speed, food habit and the food preference of the predator possibly be the main factors to selection of species. Other mechanisms as heterogeneity of habitat and environmental factors can also influence the consumption of prey by trahira.

On the relation amongst limnological factors and fish abundance in reservoirs at semiarid region

“…In both reservoirs, predators were less abundant in the dry season, with the exception of P. squamosissimus. In this season, habitats and shelters become scarcer, making it more difficult for ambush predators (Hoplias and Crenicichla) to ambush their prey (Winemiller & Jepsen, 1998;Brejão et al, 2013;Montenegro et al, 2013). In addition, Cichla and Cichlasoma, both of which are common in coastal regions (Oliveira et al, 2005;Beltrão et al, 2009), also become less abundant in the dry season.…”

Physiological responses of anti-predation in prey fish to the threat of piscivorous fish in different underwater visibility conditions

“…Hoplias aff. malabaricus is native to the upper Paraná River floodplain and inhabits mainly lake environments (Petry et al, 2010), where they act as a sit-and-wait predator (Montenegro et al, 2013). In contrast, A. crassipinnis is an exotic fish introduced by aquarists in lakes connected to the Paraná River floodplain (Abujanra et al, 2009;Julio Jr et al, 2009), where they actively pursue their prey.…”

Proporção Sexual E Relação Peso-Comprimento Do Geophagus Surinamensis (Bloch, 1791) Em Um Lago Amazônico / Sexual Proportion and Weight-Length Geophagus Surinamensis (Bloch, 1791) Amazon Lake

“…As bacias das regiões amazônicas abrigam um mosaico de diversas espécies de peixes de água doce do mundo, uma vez que sua região possui a maior floresta do mundo, bem como, um dos rios mais influentes para a biodiversidade da região. Por essa razão, acaba ganhando um importante destaque no cenário nacional e internacional (Brown-Peterson et al 2011;Rodrigues, 2013;Montenegro et al 2013;Costa & Freitas, 2015;Mereles, 2017).…”