Morphological study of the oviductal gland in the smallnose fanskate Sympterygia bonapartii (Müller and Henle, 1841) (Chondrichthyes, Rajidae)

Abstract

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.

Histological Remarks of the Uterus of Sympterygia acuta (Garman, 1877) and Sympterygia bonapartii (Müller & Henle, 1841) (Chondrichthyes; Rajidae)

“…The anatomical disposition of the uteri of Sympterygia acuta and S. bonapartii is consistent with that seen in all studied Chondrichthyes (Díaz-Andrade et al, 2011;Galíndez et al, 2010a;Hamlett & Hysell, 1998;.…”

“…When sexual development starts, all the genital system displays a transitional and progressive change, where the features of immature and mature uteri coexist. On the other hand, the morphological specializations of the uterus of sexually mature females in the studied species would be adaptations to the functional activities associated with the process of formation, modification and movement of the egg capsule (Galíndez et al, 2010a;Koob & Cox, 1993).…”

“…Even though these capsules are secreted by the oviductal glands (Galíndez et al, 2010a;Galíndez & Estecondo, 2008;Koob & Cox, 1988;Koob & Hamlett, 1998;Lucifora & García, 2004), the chemical reactions that result in the tanning and sclerotization of the capsule's wall, occur in the uterine lumen and are promoted by the conditions prevailing there (Koob & Cox 1988;. Despite this, the uterus of oviparous species has been considered primitive and unspecialized, regarding the physiological maintenance of the uterine environment and it has been studied in depth only in one oviparous species (Raja erinacea, Koob & Hamlett).…”

Reproductive aspects of the velvet belly lantern shark Etmopterus spinax (Condrichthyes: Etmopteridae), from the central western Mediterranean sea. Notes on gametogenesis and oviducal gland microstructure.

“…The oviducal gland (OG), a specialized region of the anterior oviduct, is an exclusive structure of cartilaginous fishes. The biological importance of this structure, analyzing their microarchitecture and development, is closely related to the special features of the reproductive strategy of the group, the maturity stage and reproductive cycle stage (Galíndez et al, 2010). Its basic function is the production of the egg jellies, candle/envelope formation, and transport of fertilized eggs and receptacle and /or sperm storage (Hamlett et al, 1998).…”

Reproductive biology of Sympterygia bonapartii (Chondrichthyes: Rajiformes: Arhynchobatidae) in San Matías Gulf, Patagonia, Argentina

“…During these months, an increment in the values of the OGI and MOD was recorded together with the presence of females bearing egg capsules. The increment in the values of OGI may be related to the enlargement of the oviducal glands recorded during the mating and the egg-laying season (Galíndez et al, 2010). The increment in MOD values may point out that oocytes were accumulating yolk and were ready to be ovulated when the maximum values were reached.…”