The ovary of the bignose fanskate Sympterygia acuta Garman, 1877 (Chondrichthyes, Rajidae) in the Bahía Blanca estuary, Argentina: morphology and reproductive features.
نویسندگان
چکیده
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.
منابع مشابه
Morphological study of the oviductal gland in the 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 gla...
متن کاملHistological remarks of the oviduct and the oviducal gland of Sympterygia acuta Garman, 1877.
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...
متن کاملTrypanorhynch cestodes (Eutetrarhynchidae) from batoids along the coast of Argentina, including the description of new species in Dollfusiella Campbell et Beveridge, 1994 and Mecistobothrium Heinz et Dailey, 1974.
During a recent parasitological survey of elasmobranchs along the coast of Argentina, two new species of eutetrarhynchid cestodes of the genera Dollfusiella Campbell et Beveridge, 1994 and Mecistobothrium Heinz et Dailey, 1974 were collected from batoids. Dollfusiella acuta sp. n. was found in four arhynchobatid skates, i.e. Sympterygia acuta Garman (type host), Sympterygia bonapartii Müller et...
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VALERIA ANA GUINDER1*, JUAN CARLOS MOLINERO2, CECILIA ANGELINES POPOVICH3, JORGE EDUARDO MARCOVECCHIO1 AND ULRICH SOMMER2 1 ÁREA DE OCEANOGRAFÍA QUÍMICA, INSTITUTO ARGENTINO DE OCEANOGRAFÍA (IADO-CONICET), CC 804 B8000FWB, BAHÍA BLANCA, ARGENTINA, 2 FB3, MARINE ÖKOLOGIE, LEIBNIZ-INSTITUT FÜR MEERESWISSENSCHAFTEN, IFM-GEOMAR, DÜSTERNBROOKER WEG 20, KIEL 24105, GERMANY AND 3 LABORATORIO DE FICOLO...
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عنوان ژورنال:
- Brazilian journal of biology = Revista brasleira de biologia
دوره 69 2 شماره
صفحات -
تاریخ انتشار 2009