The development of the oviducal gland in the Rajid thornback ray, Raja clavata

Abstract

The reproductive processes of chondrichthyans are complex. Knowledge of the development and maturation of the oviducal gland is vital for understanding the reproductive biology of a species. This study represents the Wrst contribution of this subject for skates. In the oviparous thornback ray, Raja clavata, oviducal gland development begins early in the developing stage with the formation of gland tubules and the distinct lamellae of each zone: club, papillary, baZe and terminal. Oviducal development is complete by the end of the developing stage when the storage and secretion of products is evident within the gland tubules of each zone. Periodic acid-SchiV and alcian blue histological staining showed that the secretory mucous cells of the club and papillary zones produce neutral and sulfated acid mucins. The last row of gland tubules of the papillary zone stains intensely for sulfated acid mucins. The baZe zone, which is responsible for the production of the egg capsule, represented 60-80% of the glandular zone of the oviducal gland. Sperm bundles were observed in the deeper recesses of the baZe zone during the maturation process, and during capsule extrusion, sperm were detected near the lumen. The terminal zone was composed of two types of gland tubules: serous (producing protein Wbres) and mucous glands (producing sulfated acid mucins).

Reproductive biology of Raja clavata (Elasmobranchii: Rajidae) from Southern Black Sea coast around Turkey

“…This finding in this study was similar to previous studies for this species (Gallagher et al 2005;Capapé et al 2007;Serra-Pereira et al 2010;Whittamore and McCarthy 2005). An abrupt increase in the gonad weight immediately after the onset of sexual maturity has been reported for species such as Raja asterias, R. wallacei, R. pullopunctata, and Atlantoraja cyclophora (Capapé 1980;Walmsley-Hart et al 1999;Oddone and Vooren 2005).…”

“…The reproductive biology of R. clavata was previously studied from specimens caught off the British coast (Holden et al 1971;Holden 1975;Gallagher et al 2005;Whittamore and McCarthy 2005;Serra-Pereira et al 2010), the Atlantic coast (Du Buit 1968;Nottage and Perkins 1983), Mediterranean Sea (Capapé et al 2007), and Adriatic Sea (Jardas 1973;Krstulovic Sifner et al 2009). However, a little information is available about the reproductive biology of this species in the Black Sea of Turkey (e.g., Demirhan et al 2005).…”

Reproductive biology of the skates Sympterygia acuta Garman, 1877 and S. bonapartii Müller & Henle, 1841 (Chondrichthyes: Rajoidei) in south Brazil

“…Serra Pereira et al (2011) analyzed the relationship of various measures of oviducal gland, including height, width and thickness, in Raja clavata (Linnaeus, 1758), in relation to maturity stages (i.e., "in development"; "spawning capable"; "actively spawning"), finding differences among stages. Differences in the OGH were also detected in S. bonapartii and S. acuta, whit their values increasing during sexual development.…”

“…Alar thorns considered as ''developing'' were registered as a circular light mark on a darker epidermis, being evident laterally on the dorsal region of both pectoral fins (sensu Oddone & Vooren, 2005) The calcification of the clasper was manually assessed and classified as "flexible" or "rigid". From females, the height of the oviducal glands, according to Serra Pereira et al (2011), the number of vitellogenic follicles larger than 1 cm (Mabragaña et al, 2002) and smaller than 1 cm (Díaz Andrade et al, 2011), the uteri width, diameter and the colour of the largest ovarian follicle, as well as the presence or absence of egg capsules in the uteri and in the cloacal region were registered (Oddone & Vooren, 2005). According to the development of the above-mentioned reproductive structures in relation to TL, the individuals were classified in three maturity categories: immature, adolescent and mature (Oddone et al, 2007a).…”

Reproductive biology of the Brazilian guitarfish, Pseudobatos horkelii (Müller & Henle, 1841) from southeastern Brazil, western South Atlantic

“…Clasper length presented a sigmoid growth pattern, a common pattern observed in several elasmobranchs (Oddone, Amorim, Mancini, Norbis, & Velasco, ; Romero‐Caicedo & Carrera‐Fernández, ; Serra‐Pereira et al., ). This suggests that clasper growth is faster when individuals are close to attaining sexual maturity.…”