Chondrichthyes have become an important economic resource in recent years. In spite of this importance, there is little knowledge about their reproductive biology, especially of species from the south-western Atlantic. In this work, we study the morphology and histology of the ovary of Sympterygia acuta. The results show that oogonia were present only in the immature females (stage I of maturity scale), whereas specimens in stages II and III of maturity displayed oocytes in all developmental steps. The most important histological features that vary throughout oocyte development are the presence or absence of yolk, the number of types and layers of follicular cells and the degree of development of the thecae. Follicular cells are, at least, of two different types. Finally, a new point of view for the determination of maturity stages in the field based on the size of follicles is discussed.
The elasmobranchs constitute an important resource in Argentinian fishing and they show reproductive characteristics that make them susceptible to the pressure of fishing. In spite of the importance of the resource our knowledge about the species of the Southwestern Atlantic is scarce. In this work we study the microanatomy of the oviduct and the oviducal gland of Sympterygia acuta. The results show a very folded oviduct with mucous and ciliated cells. The oviducal gland depicts the same zonation as other batoids, showing the typical four regions (club, papillary, baffle and terminal). The epithelium lining the glandular lumen is simple columnar with ciliated and glandular cells. The four zones show simple or ramified tubular gland the secretions of which constitute the egg's envelopes. The club and baffle zones are similar to those present in other species. The papillary one depicts a different pattern of secretions that other Rajiformes and the last zone of the gland is characterized by mixed adenomers. The information here exposed constitutes the first report on the microanatomy of the genital tract of S. acuta.Keywords: Elasmobrachs, oviducalgland, reproduction, Sympterygia acuta. Observações histológicas do oviduto e da glândula oviducal de Sympterygia acuta Garman, 1877 ResumoOs elasmobranchii constituem um importante recurso pesqueiro na Argentina e mostram características reprodutivas que os fazem suscetíveis à pressão de pesca. Apesar da importância do recurso, nosso conhecimento sobre as espécies do Atlântico do Sudoeste é escasso. Neste trabalho, estudamos a microanatomia do oviduto e da glândula oviducal de Sympterygia acuta. Os resultados mostram um oviduto muito dobrado, com células mucosas e células ciliadas. A glân-dula oviducal apresenta as mesmas zonas que outros batóideos, mostrando as quatro regiões típicas (club, papillary, baffle e terminal). O epitélio que reveste o lúmen glandular é simples, com células ciliadas e células glandulares. As quatro zonas mostram glândulas tubulares simples ou ramificadas e suas secreções constituem os envelopes do ovo. As zonas do club e baffle são semelhantes aquelas presentes em outras espécies. A papilar tem um padrão de secreção diferente de outros Rajiformes e a última zona da glândula é caracterizada por adenômeros mistos. A informação aqui exposta constitui o primeiro relato sobre a microanatomia do trato genital de S. acuta.Palavras-chave: Elasmobranchii, glândula oviducal, reprodução, Sympterygia acuta.
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.Keywords: Chondrichthyes, Rajidae, oviductal gland, reproductive biology, Sympterygia bonapartii. Estudo morfológico da glândula oviductal no smallnose fanskate Sympterygia bonapartii (Müller and henle, 1841) (Chondrichthyes, Rajidae) ResumoA 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.
The histology of the salivary glands of the armadillo Zaedyus pichiy (Desmarest, 1804) was studied. Three pairs of major compound tubuloacinar salivary glands, parotid, submandibular and sublingual, were distinguished. The parotid gland is histologically a serous gland. The submandibular gland consists of two lobes. The anterior lobe is composed of mixed and serous acini. The posterior lobe is predominantly mucous. There is a reservoir or salivary bladder, related with the anterior lobe. The sublingual gland is mixed, composed of mucous acini with scattered serous demilunes.
SUMMARY:Chondrichthyes have become an important economic resource in the last decades, with Argentina as one of the countries that exploits more sharks and skates, even at levels that exceed de limits of many species. However, there is a scarce knowledge of the reproductive biology of this group, particularly from species inhabiting the Southern hemisphere. This work shows the most relevant facts during folliculogenesis in Sympterygia bonapartii. Results show that germinal cells are present in immature and maturing females. The most important facts that vary along de follicular development are the number of types and layers of follicular cells, the establishment of thin projections from the follicular cells and the degree of development of the thecae. Follicular cells are, at least, of two different types and both of them emit projections that break through the zona pellucida. The outer theca shows signs of synthetic activity. Atretic follicles of different sizes are present in exemplars of all the reproductive stages. These results are discussed in a physiological and adaptive context.
The dorsal surface of the tongue of Zaedyus pichiy (Desmarest, 1804) was examined by scanning electron microscopy. Conical and branched filiform, fungiform and vallate papillae are described. No foliate papillae were seen. Conical filiform papillae are distributed in the apex, both lateral edges and caudally to the vallated ones. The branched papillae represent the most numerous type of lingual papillae; they are distributed over the entire dorsal surface of the tongue. The fungiform papillae are placed among the filiform ones, more densely distributed on the tip of the lingual apex. In the posterior third of the tongue there are two vallated papillae surrounded by a deep circular grove. Fungiform and circumvallate papillae are related to the sense of taste; openings of taste pores are visible on their surface. The filiform papillae have a mechanical and protective role.
The dorsum of the tongue of Dasypus hybridus (Desmarest, 1804) studied by scanning electron microscopy, shows conical and branched filiform, fungiform and vallate papillae. No foliate papillae were seen. Conical filiform papillae are placed in the apex of the tongue and posterior to the vallated ones. Branched papillae are compactly distributed over the entire dorsal surface of the tongue. Fungiform papillae are more abundant on the first third of the tongue and they are distributed between filiform papillae. Only two vallate papillae were observed placed in the posterior third of the tongue, surrounded by a deep grove. The presence of taste buds on fungiform and vallate papillae indicate that both are involved in the sense of taste, while the filiform ones have a mechanical and protective role. The morphological characteristics of the tongue of Dasypus hybridus are comparable with those of other species of armadillos.
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