Acute toxicity of diuron and glyphosate in megalopae of Callinectes sapidus from the Jamapa River Estuary, Veracruz

Abstract

The objective of this work was to evaluate the acute toxicity of the commercial herbicides Karmex® (diuron: DCMU 3-(3,4-dichlorophenyl)-1,1-dimethylurea) and Herbipol® (glyphosate: N-(phosphonomethyl) glycine) on the megalopae of Callinectes sapidus and measure their relative abundance in the association of larval and postlarval species of crustaceans from the estuary of the Jamapa River, Veracruz. Collections were made overnight using white light traps. Likewise, dissolved oxygen, pH, temperature, total dissolved solids, and salinity were measured in situ. It was found that the association of larvae and postlarvae consisted of Macrobrachium acanthurus, M. olfersii, Potimirim mexicana, megalopae of C. sapidus and Armases ricordi, and zoeas of Brachyura. In total, 559 and 1057 C. sapidus megalopae were collected in November and March 2019, respectively. Dissolved oxygen was 6 and 7 mg L-1, pH was 7 and 8, the temperature was 26 and 27°C, total dissolved solids were 700 and 1500 ppm, and salinity was 0.70 and 16 in November and March, respectively. Using Probit analysis, a 96 h LC50 of diuron (Karmex®) was 7.69 ± 1.07 mg L-1 in March and 6.64 ± 0.93 mg L-1 in November. The LC50 for glyphosate (Herbipol®) was 247.83 ± 34.54 mg L-1 in March and 288.18 ± 38.66 3 mg L-1 in November. The blue crab C. sapidus is tolerant to a wide range of physicochemical factors; however, it is sensitive in the postlarval stages, like other species of crustaceans, to the herbicides diuron and glyphosate, for which the megalopae can be used in ecotoxicological studies.