Histochemical study of the oviducal gland and analysis of the sperm storage tubules of Mustelus schmitti Springer, 1939 (Chondrichthyes, Triakidae)

The paired oviducal glands of immature and mature females of Mustelus schmitti were examined macro and microscopically. Findings indicate that these glands possessed the same zonation as in most chondrichthyans from anterior to posterior: club, papillary, baffle and terminal zones. The whole gland is composed by simple tubular glands that connect with transverse grooves all along the organ. The club zone presents a typical indian club shape with a simple columnar and ciliated epithelium including secretory cells PAS (+) and AB (+). The papillary zone is characterized by lamella forming small and long cones in numbers of three. The epithelium of this zone contains ciliated cells with apical nuclei and secretory cells with basal nuclei that stain AB (+)The baffle zone consists of apically flattened lamellae alternating with spinnerets which are small projections disposed by both sides of the plateau. This whole structure is present in number of 8 or 9 units. A simple columnar ciliated epithelium covers the plateau and spinnerets and no AB or PAS staining is observed. The epithelium of the terminal zone is PAS (-) and AB (+), and elongated tubules, that run adjacent to the baffle zone are the site where groups of spermatozoa are clearly observed in the lumen. The epithelium of the sperm storage tubules do not stain with any of the dyes tested. Sperm was also observed in the baffle zone, presumably in its way to the fecundation in the oviduct because it displays no aggregation pattern and was between the folds of the epithelium. By scanning electron microscopy sperm was observed in the club and baffle zones in a gland which belonged to a pregnant female...

Morphological study of the oviductal gland in the smallnose fanskate Sympterygia bonapartii (Müller and Henle, 1841) (Chondrichthyes, Rajidae) / Estudo morfológico da glândula oviductal no smallnose fanskate Sympterygia bonapartii (Müller and henle, 1841) (Chondrichthyes, Rajidae)

The oviductal gland is an exclusive structure of cartilaginous fishes that produces the egg jelly, forms the tertiary egg envelopes and stores sperm. The biological importance of this structure is related to the special features of the reproductive strategy of the group and to its phylogeny, considering that egg-laying is the ancestral condition in this fish (Dulvy and Reynolds, 1997). This gland of the smallnose fanskate shows four morphofunctional zones. The lining epithelium along the gland is columnar with secretory and ciliated cells. Secretions are mucous and/or proteic according to the zone, and to their specific functions. This is the first report about the microanatomy of the female reproductive tract of S. bonapartii with evidence of sperm storage in the genus.

A glândula oviductal é uma estrutura exclusiva das elasmobrânquias que produz a geléia do ovo, o envoltório terciário do ovo e armazena espermatozóides. Sua importância está relacionada com as características especiais da estratégia reprodutiva do grupo e com a filogenia destes peixes em que oviparidade é a condição ancestral (Dulvy and Reynolds, 1997). A glândula oviductal do smallnose fanskate mostra quatro zonas morfofuncionais. O revestimento em toda a glândula é epitélio colunar ciliado com células glandulares e ciliadas. As secreções são diferentes entre as zonas e relacionada com as suas funções específicas. A informação aqui exposta constitui o primeiro relato sobre a micro-anatomia do trato reprodutivo feminino de S. bonapartii com evidencias de armazenamento do esperma neste gênero.