Some ecological and toxicological studies on crayfish, Procambarus clarkii at Sharkia Governorate, Egypt

The Louisiana red swamp crayfish, Procambarus clarkii, which was introduced into Egypt in the1980s, has since become widespread across the country. Burrowing behavior of P. clarkii, was investigated in irrigation canal of three different sites (Abou-Kabir, Abou-hammad and Belbies) at Sharkia Governorate from January 2014 to December 2015. Most burrows were simple in their morphology and few of them had two types of chimney (plugged and open). Open chimney was present at 100 cm of the edge side of irrigation canal, while plugged cap chimney was located inside the agriculture soil. Result indicated that a great number of P. clarkii were observed migrating across roadways to find the main irrigation canal, during their crossing many of them were killed by cars. The highest mean numbers of burrows and population density of P. clarkii were recorded at Abou-Kabir followed by Abou-hammad while Belbies was the lowest one in this respect during two successive years of 2014 and 2015. Furadan 10G is routinely applied in Egypt rice fields was examined in the laboratory against P. clarkii in trial to control its explosive populations in certain closed habitats. Data showed that after 96 h, at the higher concentrations (70 ppm) 100 and 90% of mortality were recorded for adult males and females of P. clarkii, respectively while at lower concentrations (50 ppm) the mortality was 70 and 60% for both sexes respectively. LC₅₀ of furadan was 58.26 and 63.60 ppm for adult males and females, respectively.