Life history trait variations and population dynamics of Calophysus macropterus (Siluriformes: Pimelodidae) in two river systems of the Colombian and Peruvian Amazon

Abstract

The catfish Calophysus macropterus is heavily exploited in the Amazon basin, yet its life history characteristics are poorly documented, hampering proper fisheries management. In order to fill this gap, monthly sampling in the upper Putumayo River and in the Amazonas, lower Marañón and Ucayali (AMU) rivers were carried out over several years (2013-2015 in the AMU, 2013-2017 in the Putumayo) to provide detailed information about its reproduction, growth and mortality patterns (using length frequency data). Reproduction, which occurs during the dry and early flooding season, was only observed in the upper Putumayo River and not in the sampled portion of the AMU system, suggesting that the species reproduces closer to the Andes than other pimelodid catfishes. Size at first sexual maturity did not differ significantly among sex or among river systems, ranging from 25-28 cm SL. In both river systems, females had a faster growth than males and both genders also tended to have a better growth in the AMU than in the upper Putumayo. Mortality and exploitation estimate all indicated overexploitation of the species in both river systems. The implications of these results for fisheries management and conservation are discussed.

Mercury in aquatic ecosystems of two indigenous communities in the Piedmont Ecuadorian Amazon: evidence from fish, water, and sediments

“…S3 ). This species has repeatedly been found to have high levels of THg throughout the Amazon (Beltran-Pedreros et al 2011 ); its consumption has recently been banned in Brazil and Colombia (Bonilla-Castro 2022 ). Possibly, the high THg values of this species influenced the result from Gomataon, where piscivores don’t have an effect on the covariance analysis.…”

“…Migratory and widely distributed fish like S. hilarii (Esguícero and Arcifa 2010 ), C. macropterus (Bonilla-Castillo et al 2022 ), P. blochii (Kerguelén-Durango and Atencio-García 2015 ) and A. torosus (Stewart 1986 ) exhibited high THg. The incidence of migratory fish with high levels of mercury can be attributed to multiple causes, including pollution of aquatic ecosystems elsewhere from where fish migrate, feed, or mate (Reis et al 2020 ).…”