ONTOGENY OF FEMALE PRIMARY SEXUAL CHARACTERS IN THE MAJID CRABS CHIONOECETES-OPILIO AND HYAS-COARCTATUS

To investigate the development of primary sexual characters in the fam ily Majidae, the spermathecae, ovaries, and oviducts of juvenile femal e Chionoecetes opilio and Hyas coarctatus were examined, using histolo gy, histochemistry, and electron microscopy, and compared to those of mature females. Females were divided into 3 developmental categories, with corresponding size ranges, based on anatomical criteria: immature , premature, and mature. Immature crabs were still temporally remote f rom the terminal molt, had white ovaries, and the spermatheca presente d a thin tissule separation between the dorsal and ventral regions. No stratified glandular epithelium was present; only a columnar epitheli um lined the lumen. This epithelium tested slightly positive for amine -containing substances. Premature females were temporally close to ter minal molt, had orange ovaries, and retained the tissule separation be tween the dorsal and ventral regions of the spermatheca. In addition, they presented a stratified glandular epithelium which developed benea th the columnar epithelium lining the lumen. The latter degenerated an d sloughed into the lumen as the former developed. Mature females had undergone the terminal molt, and were examined both prior to and follo wing egg extrusion. No trace remained of the columnar epithelium which was present in the preceding two categories. In mature females which had extruded eggs, the tissule separation between dorsal and ventral r egions of the spermatheca was also absent. Neutral mucopolysaccharides dominated in the secretions of the dorsal glandular epithelium of bot h types of mature female. These results establish the primary sexual c haracters in female C. opilio and H. coarctatus, and also document the sequence of aquisition of these characters.