THE SLOW MUSCLES IN THE UROPOD OF CRAYFISH, PROCAMBARUS-CLARKII

1. 1. The fiber types of uropod muscles of the crayfish, Procambarus clarkii, were determined by the myofibrillar ATP-ase histochemistry and electrophysiology. 2. 2. The ATP-ase histochemistry was carried out on the sections of the whole tailfan and the slow muscles were identified as being of the slow type on the basis of their low staining intensities. 3. 3. The location of slow bundles in the mixed type muscles i.e. the dorsal rotator (DRT), the ventral rotator (VRT), and the telson-uropodalis posterior (TUP) was confirmed. 4. 4. TUP was newly revealed in this study to be a mixed muscle. © 1990.