The bluemouth rockfish, Helicolenus dactylopterus dactylopterus (De la Roche, 1809), is a zygoparous species with internal fertilization. The male urogenital papilla acts as the copulating organ, and the females retain the spermatozoa in their ovaries for up to 10 months. The objective of this study is to extend our knowledge of the mechanisms that allow the sperm to be retained in the ovaries for prolonged periods. To this end, we analyze the histochemical properties of: 1) the epithelium of the testicular sperm duct, 2) the sperm of the males, 3) the internal epithelium of the ovary wall, 4) the ovarian fluid, and 5) the spermatozoa storage crypts of females. The PAS (Periodic acid-Schiff) and bright Coomassie blue positive reactions of the epithelium of the spermatic duct point to the secretion of polysaccharides and proteins that could promote the bundling of the spermatozoa. The internal epithelium of the ovarian wall secretes polysaccharides, protein, and lipid compounds throughout the storage and spawning period. The acid nature of the ovarian fluid during the storage period may maintain the bundling of spermatozoa when they enter the ovary and may also inhibit sperm motility until the moment of fertilization. The polysaccharide granules that come from the cryptal epithelium into the cavity where spermatozoa are maintained may supply them with nutrients for the storage period. The presence of glucosaminoglycans on the surface of the sperm is probably related to the inhibition of spermatic motility produced by the acidic environment. They are absent in the spermatozoa located in the testicular ducts, relatively scarce in those of the duct of the copulating organ, and abundant in those within the intraovarian cryptal structures.
Copyright 2002 Wiley-Liss, Inc.