Effects of Endosulfan on Predator-Prey Interactions Between Catfish and Schistosoma Host Snails.

Concillia Monde,Paul J Van Den Brink,Stephen Syampungani

doi:10.1007/s00244-016-0275-7

Concillia Monde, Paul J Van Den Brink + Show 1 more

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https://doi.org/10.1007/s00244-016-0275-7

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Abstract

The effect of the pesticide endosulfan on predator–prey interactions between catfish and Schistosoma host snails was assessed in static tank experiments. Hybrid catfish (Clarias gariepinus × C. ngamensis) and Bulinus globosus were subjected to various endosulfan concentrations including an untreated control. The 48- and 96-h LC50 values for catfish were 1.0 and <0.5 µg/L, respectively, whereas the 48- and 96-h LC50 values for snails were 1137 and 810 µg/L. To assess sublethal effects on the feeding of the catfish on B. globosus, endosulfan concentrations between 0.03 and 1.0 µg/L were used. Predation was significantly greater (p < 0.001) in control tanks than in all other treatments. There was progressively decreasing predation with increasing toxicant concentration. Biological control of Schistosoma host snails using fish may be affected in endosulfan-polluted aquatic systems of Southern Africa because it has been found present at concentrations that are indicated to cause lethal effects on the evaluated hybrid catfish and to inhibit the predation of snails by this hybrid catfish.Electronic supplementary materialThe online version of this article (doi:10.1007/s00244-016-0275-7) contains supplementary material, which is available to authorized users.

Highlights

The effect of the pesticide endosulfan on predator–prey interactions between catfish and Schistosoma host snails was assessed in static tank experiments
The aim of this study was to assess the toxic effect of endosulfan on both the predator hybrid catfish and the prey B. globosus as well as on the predation efficiency of the hybrid catfish
Muthukumar et al (2009) observed a rapid increase in opercular movements of Tilapia mossambicus exposed to sublethal concentrations of endosulfan as a way of increasing oxygen uptake to mitigate the stress caused by the toxicant

Summary

Introduction

The effect of the pesticide endosulfan on predator–prey interactions between catfish and Schistosoma host snails was assessed in static tank experiments. Results from these studies have shown that different pesticides can disrupt intraspecific and interspecific interactions between organisms and alter the ecological functioning of ecosystems (Bridges 1999; Relyea and Hoverman 2006; Junges et al 2010) This could occur by causing mortality of either the predator or prey or by interfering with their physiology. In many of these countries studies to quantify the effects of these pollutants on the environment have rarely been performed One such pesticide with persistent effects to the environment still in use in southern African is endosulfan (Deedat et al 1997; Stockholm Convention on Persistent Organic Pollutants Review Committee 2010)

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