Regeneration of the antennules in the Australian freshwater crayfish, Cherax destructor.

Abstract

AbstractRemoval of one eye from the Australian freshwater crayfish, Cherax destructor, results in the growth of a heteromorph appendage which re‐ sembles the outer flagellum of the antennule. The heteromorph is con‐ sistently uniramous.Transplanting part of the animal's own antennule into the eye stalk after removal of the ipsilateral eye results in a significant number of biramous appendages being developed in the eye socket. Biramous appendages when they possess fully differentiated hairs, can be identified as being the external and internal flagella of the antennule. Triramous appendages were never observed.The specificity of the antennular sensilla was tested in relation to the cleaning behavior released by stimulating them electrically. Sensilla on the external flagellum of the antennule produce depression of the antennule and cleaning using the maxillipeds. This behavior is also produced when the heteromorph appendage is stimulated although in this case it is misdirected. Stimulation of the hairs in the eye socket releases cleaning of the eye socket with the 2nd and 3rd walking legs. Eye socket cleaning is not released by stimulation of the heteromorph indicating that the antennular sensilla retain their specificity in relation to the cleaning behavior released.Removal of the antennule results in the ipsilateral olfactory lobe becoming smaller than the contralateral lobe. No change was observed in the accessory lobes.