Sub-lethal concentrations of monocrotophos affect aggressive behavior of the fishes Astyanax altiparanae Garutti & Britski (Teleostei, Characidae) and Oreochromis niloticus (Linnaeus) (Teleostei, Cichlidae)

Abstract

ABSTRACT. This study investigated the effects of sublethal concentrations of the pesticide monocrotophos (organophosphate) on the agonistic behavior of two fishes species, Astyanax aitiparallae Garutti & Britski, 2000 (Iambari) and Oreochromis niloticus (Linnaeus, 1758) (Nile tilapia). Sublethal concentrations of the pesticide for the two species were determined and lambari was more resistant than Nile tilapia. The sublethal concentrations were smaller than 400 mgr ' for lambari and 20 mgr' for Nile tilapia. The two species were tested in grouping condi tions (triads) and isolation, under monocrotophos concentrations of 200 mgr ' fo r lambari and 5 mgr ' for Nile tilapia. The concentration decreased the aggressiveness in I arnbari , but in Nile tilapia an opposite effect was detected. The results show a species-specific effect of the monocrotophos on aggression.

Acute toxicity of monocalm 400sl (<i>monocrotophos</i>) and profenalm 720ec (<i>profenofos</i>) on <i>Oreochromis niloticus</i> (Linnaeus, 1758)

“…(Kidd and James, 1991;Tomlin, 1994). Cruz (2002) found a 48h-LC50 of monocrotophos equal to 400 mgL -1 , for Astyanax altiparanae (Lambari).…”

“…Cruz (2002) had also conducted a study on acute toxicity of monocrotophos to O. niloticus and had found a 48h-LC50 of 20 mgL -1 . This value is noticeably close to that obtained in the course of our work.…”

Acute toxicity of monocalm 400sl (<i>monocrotophos</i>) and profenalm 720ec (<i>profenofos</i>) on <i>Oreochromis niloticus</i> (Linnaeus, 1758)

“…These findings, compared with those obtained in this work; show that A. altiparanae and L. macrochirus are more resistant to monocrotophos than O. niloticus, which appears to be less sensitive than O. mykiss. Cruz (2002) had also conducted a study on acute toxicity of monocrotophos to O. niloticus and had found a 48h-LC50 of 20 mgL -1 . This value is noticeably close to that obtained in the course of our work.…”

Haematological Recovery by Vitamin E and C on Paraquat Inflicted Haematological Insult in Rattus norvegicus

“…When agrochemicals are used extensively and intensively to meet the agricultural requirements of the population, also the indiscriminate use or misuse of these agrochemicals results in the poisoning of the biosystem [1,2] A lot of pesticides used to kill weeds have been proven to have an effect on the biosystem [3,4]. Even though the use of these pesticides has increased agricultural productivity, there are reports of increasing mortality of aquatic organisms after exposure to these toxicants, which in most cases are discharged accidentally [5].…”

“…Organisms are subjected to long term effects (stress) resulting from chronic exposure which may also cause death in the organism or as toxicants to consumers of such organism [5,6]. However, it has been reported that chronic levels of these chemicals can cause changes in behaviour [3], histopathology [4], enzymes and metabolites [7] feeding habits and feed conversion ratio [8] and haematological parameters [1].…”