ULTRASTRUCTURAL-STUDY OF THE NEUROSECRETORY GRANULES AND CRUSTACEAN HYPERGLYCEMIC HORMONE (CHH) IMMUNOLOCALIZATION IN THE SINUS GLAND OF HOMARUS-GAMMARUS

Seven different types of neurosecretory granules have been observed in tile axon terminals of the sinus gland of the adult female lobster Ho marus gammarus. They were discriminated through morphometrical and mor phological criteria such as size, shape, frequency of occurrence, elec tron density, and axon-matrix density. Each size distribution followed a single Gaussian-type distribution. Each axon terminal contained 1 t ype of granule. The mean granule diameter ranged from 50 nm (type 1) t o 161 nm (type 7). Type 6 and type I axon terminals were, respectively , the most and least frequent. An immunopositive reaction against an a nti-Homarus americanus CHH was detected in the 2 largest types of gran ules: type 6 (mean diameter, 128 nm) and type 7 (mean diameter, 161 nm ).