An appendage abnormality in the first left pereiopod of red swamp crayfish (Procambarus clarkii) reared in the laboratory conditions

Red swamp crayfish (Procambarus clarkii) is the most cultivated crayfish species in the world that has commercial importance for both aquaculture and aquarium industries. In this study, a case report of an appendage abnormality observed in the left cheliped of a female specimen (6.92 g) reared under laboratory conditions is presented. It has been determined that the specimen has two appendages in the left cheliped root. Of these appendages, the left one (1.06 cm) ends in a blunt. On the right (1.27 cm), a spiny structure similar to that of the fourth and fifth walking legs was observed.