Effects of Chlorpyrifos and Endosulfan on Different Life Stages of the Freshwater Burrowing Crab Zilchiopsis collastinensis P.: Protective Role of Chorion

Abstract

The lethality (LC50) of endosulfan and chlorpyrifos is higher in adults (1990 and 156.78 μg/L respectively) than in embryos (95380 and 1242.54 μg/L respectively) of the crab Zilchiopsis collastinensis. The thickened embryonic coat of the freshwater species might isolate the embryo inside the egg, reducing the toxicity. Sublethal concentrations of chlorpyrifos and endosulfan caused an increase in hatching time and a decrease in effective hatching (p < 0.05), and only the control crabs survived until the first molt cycle. The effects of long-term exposure should be evaluated in the offspring in addition to the acute toxicity.

Histopathological effects of endosulfan to hepatopancreas, gills and ovary of the freshwater crab Zilchiopsis collastinensis (Decapoda: Trichodactylidae)

“…The females of this species appear to be quite resistant to endosulfan. In previous studies conducted by us, the 96-h LC 50 of endosulfan was found to be 1902 mg/l (Negro et al, 2014). When Z. collastinensis was exposed to endosulfan for 22 days, accumulation of this pesticide was found to have occurred both in hepatopancreas and gonads, although there was a reduction with time of endosulfan concentrations in hepatopancreas (Negro et al, 2012).…”

“…The commercial product was diluted in dechlorinated water, added to each aquarium and gently homogenised throughout the tank. Based in the LC 50 of 1902 (1679-2124) mg endosulfan l À 1 , obtained in a 96 h exposure period test, three sublethal concentrations (about 1/20, 1/10 and 1/ 5) were used (Negro et al, 2014). Initial concentrations were 9476; 192710 and 360 715 mg endosulfan l À 1 (C 1 , C 2 and C 3 respectively).…”

Impacts of oxidative stress on acetylcholinesterase transcription, and activity in embryos of zebrafish (Danio rerio) following Chlorpyrifos exposure

“…These data indicate developmental differences in AChE expression and catalytic activity which may allow younger animals to be more resistant to OPs than older animals. Zebrafish embryos have a chorion that is present approximately the first 48 hpf (Kimmel et al, 1995) and several studies have demonstrated a protective role of the chorion for pollutant toxicity (Helmstetter and Alden, 1995;Kais et al, 2013;Negro et al, 2014). This implies that CPF uptake may be reduced until hatching occurs.…”

Effect of Benzophenone-3&nbsp;to Acetylcholinesterase and&nbsp;Antioxidant System&nbsp;in Zebrafish (Danio Rerio)&nbsp;Embryos&nbsp;

“…It has also been documented a low gene expression of antioxidant enzymes in D. rerio in response to prooxidants because of immature antioxidant and detoxi cation systems (Rodríguez-Fuentes et al 2015a). The chorion also plays an essential protective role (Embry et al, 2010;Negro et al, 2014). The chorion is present in the embryo of D. rerio until 48 hpf (Kimmel et al 1995); therefore, the organisms are directly exposed to the contaminants for a shorter time.…”