Seasonal activity of fresh water crayfish, procambarus clarkii (decapoda : cambaridae)‎ in irrigation canal of abou-kabir, sharkia governorate, Egypt

الملخص EN

The red swamp crayfish, procambarus clarkii (girard) (decapoda: cambaridae) which was introduced into the egyptian fresh water system, became widely distributed all over the country.

the seasonal activity of p.

clarkii, was conducted using baited trap in irrigation canal of abou-kabir (gynabeit bahr fakous), sharkia governorate during the year 2016, through direct counts of active animals caught throughout 24 hours period.

the results revealed that the number of caught crayfish fluctuated during the year, the highest catchability (activity) synchronized with high temperature prevailing in summer seasons as compared with those prevailing in spring and autumn seasons.

large crayfish (> 60 mm tl) were the most dominant in catches during the whole search period, whereas medium size (35-60mm tl) were more common in summer than spring and autumn, both sizes were mostly active at night.

small size crayfish (<35mmtl) were more abundant in spring, autumn but absent in summer and were mostly active at daylight.

females were dominant over males during spring, while males were dominant over females during summer and autumn.