Pyrethroid toxicity in silver catfish, Rhamdia quelen

Abstract

This study aimed to determine both the lethal and sublethal concentrations of Cypermethrin in young Silver Catϐish (Brazilian "Jundiá", Rhamdia quelen) on aquatic environment during 96 hours, as well as to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development period of Rhamdia quelen, and to verify their respective rates of fertilization, hatching and survival. Pyrethroid nowadays is a widely used insecticide, which presents a high toxicity to ϐish. In order to determine lethal and sublethal concentrations, 120 silver catϐish were used; each one had an average weight of 59.58±4.50g and an average size of 20.33±2.34cm. Concentrations used were 0, 1.0, 1.5, 2.0, 2.5, 3.0, 5.0, 10.0, 15.0 and 20.0mg of Cypermethrin per liter of water (mg/L). Fish were exposed to the product in 30-liter ϐish tanks. In each ϐish tank there were four ϐishes and the product was applied three times, i.e., a total of twelve ϐish were exposed to the product at each application, and a total of 120 ϐish during the entire experiment (n=120). In order to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development, ovulation induction was performed on female ϐishes using hormones, and then and egg collection was performed. The eggs were then hydrated and fertilized in Cypermethrin and Deltamethrin in different concentrations: 0.001, 0.01, 0.1, 1.0 and 10.0mg/L of Cypermethrin and 0.001, 0.01, 0.1, 0.5 and 1.0mg/L of Deltamethrin, in addition to the control group (0mg/L). After fertilization, the eggs were kept in containers with the respective pesticides of Cypermethrin and Deltamethrin until hatching, when hatching rate was veriϐied. Then the alevins, from the hatching, were kept on their respective concentrations of Cypermethrin and Deltamethrin so that the survival rate could be analyzed regarding the tested insecticides, during both 12-hour and 24-hour periods. Concerning the sublethal and lethal concentrations, Silver Catϐish was sensitive to the tested concentrations of Cypermethrin, showing symptoms of poisoning, such as loss of balance, swimming alteration, dyspnea (they kept their mouths and opercula open), upright swimming and sudden spiral swimming movements. The intensity of such symptoms varied in proportion to the concentration used. The concentrations above 3.0mg/L were considered lethal to the species, since every animal exposed to concentrations between 3.0 and 20.0mg/L had died, while concentrations between 1.0 and 2.5mg/L were considered sublethal. Deltamethrin during the initial embryonic development, the results show that both pyrethroids had signiϐicantly decreased the analyzed parameters when comparing them with the control group. It was concluded that, even with the ϐish being more resistant to pyrethroids in comparison with other species, both the young animals and the ones in stage of embryonic development were susceptible to the effects of these pesticides. Para determinação da concentração letal e subletal foram...

Synthetic pyrethroids (Type II) and freshwater fish culture: Perils and mitigations

“…Montanha et al (2012) studied the behavior of silver catfish exposed to sub-lethal concentrations of cypermetrhin and reported symptoms of poisoning, such as loss of balance, swimming alteration and dyspnea. Breathing and neurological disorders have been reported as a result of cypermetrhin exposure in guppies, Poecilia reticulata (Polat et al 2002;Yilmaz et al 2004), silver catfish, Rhamdia quelen (Borges 2007).…”

Hematologic, biochemical, genetic, and histological biomarkers for the evaluation of the toxic effects of fipronil for Rhamdia quelen

“…The LC 50 values presented for these fish are lower than the concentrations used in this study, except for the common carp (Cyprinus carpio), for which the LC 50 is close to that found for silver catfish (Rhamdia quelen). Silver catfish (Rhamdia quelen) has been shown to be more resistant than other species in acute toxicity tests for LC 50 determination of several pesticides (6,12).…”

Reproductive aspects of freshwater fishes exposed to pesticide-contamined environments: A systematic review

“…Once in contact with the aquatic biota, Endosulfan can affect the normal regulation of numerous biological processes, including fish reproduction (Han et al, 2011), acting as an endocrine disruptor, which affects hormonal regulation and thus causes reproductive disorders (Cuña et al, 2016). In turn, cypermethrin, a type II synthetic pyrethroid insecticide with high efficiency and low residual power with low toxicity for mammals and birds, is also part of the group of pesticides with great toxic potential in fish due to slower metabolism and elimination in fish than in other vertebrates (Moore et al, 2001;Montanha et al, 2012;Kutluyer et al, 2016). The mechanisms of action of the pesticides show effects at different levels of toxicity, with reproductive endocrine disorders being the most reported in more than 50% of the analyzed studies.…”

“…The historical development of cities and agricultural growth have accelerated the degradation of natural environments through an increase in the disposal of various contaminants in aquatic environments (Begum, 2004;Marques and Américo-Pinheiro, 2020). This situation mainly affects freshwater bodies, leading to reduced availability of good-quality water for human supply, in addition to changes in physicochemical characteristics that support the maintenance of the natural biodiversity of aquatic fauna and flora (Massaro, 2006;Montanha et al, 2012;Paschoalini et al, 2019).…”