Seasonal changes in shark testicular structure and spermatogenesis

Parsons, Glenn R.; Grier, Harry J.

doi:10.1002/jez.1402610208

Cited by 89 publications

(81 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Even though, the observations made in this study correspond only to two seasons, these are in agreement with Parsons & Grier (1992). These authors stated that the definition of the testicular coverage of each stage is a useful tool to determine a seasonal cycle of activity in this group of fish, especially when these data are correlated with mating activity observations and gonadosomatic indexes.…”

Section: Tab I Size and Nuclear Dimensions Of Maturative Spermatogesupporting

confidence: 88%

“…This organization pattern could be interpreted as an adaptation to the "flattened" body of these fish. Parsons & Grier (1992) have analyzed the changes in spermatocysts diameter of Sphyrna tiburo (Linnaeus, 1758), and reported that there was an increase in diameter until the stage of cysts containing secondary spermatocytes. However, in S. bonapartii there was an increase in diameter until the cysts with spermatids, which are the largest ones.…”

Section: Tab I Size and Nuclear Dimensions Of Maturative Spermatogementioning

confidence: 99%

See 1 more Smart Citation

Morphology and dynamics of male gametogenesis in Sympterygia bonapartii (Chondrichthyes, Rajidae) from Northern Patagonia

Moya

Andrade

Galíndez

2015

Iheringia, Sér. Zool.

View full text Add to dashboard Cite

ABSTRACT. The smallnose fanskate, Sympterygia bonapartii Müller & Henle, 1841 is one of the most disembarked items in commercial harbors in Argentina. In this work, the microscopic architecture of mature male gonads and the dynamics of cysts development are analyzed as a contribution to awareness of the reproductive biology of the species. Some biological data related to reproduction are given as well. Two seasons were sampled (fall and spring) and length classes's frequency distribution and maturity stages frequency distribution are given. Size at first sexual maturation for males was estimated at 57 cm of total length. Testes are symmetric, peer, lobed, with several germinal zones. Inside the gonads, there are many spermatocysts, containing reproductive cells at the same developmental stage. On the basis of their cytological and microanatomical features, several maturative degrees of the spermatogenic series were differentiated. Few Leydig cells were recognized at the interstitial tissue among cysts. The microscopic and semiquantitative analysis performed in this work provides morphological information about male gametogenesis and some biological data for the North Patagonian population of this economically and ecologically important species.

show abstract

Section: Tab I Size and Nuclear Dimensions Of Maturative Spermatogesupporting

confidence: 88%

Section: Tab I Size and Nuclear Dimensions Of Maturative Spermatogementioning

confidence: 99%

Morphology and dynamics of male gametogenesis in Sympterygia bonapartii (Chondrichthyes, Rajidae) from Northern Patagonia

Moya

Andrade

Galíndez

2015

Iheringia, Sér. Zool.

View full text Add to dashboard Cite

show abstract

“…In our opinion, it might be connected to individual variability reported among cartilaginous fishes. In the reproductive system of cartilaginous fishes, individual variability has been reported regarding the presence of gonia during the early stage of embryonic development (Beard, 1904), as well as follicle (Mellinger, 1974) and Leydig cells distribution, data that support the concept of "reproductive plasticity" expressed by Parsons and Grier (1992). Such a variability is extremely important as it would represent the variation targeted by natural selection, and it may possibly account for the different reproductive strategies adopted by cartilaginous fishes.…”

Section: Discussionmentioning

confidence: 90%

An ultrastructural study of germ cells during ovarian differentiation in Torpedo marmorata

2001

View full text Add to dashboard Cite

An ultrastructural investigation, performed on embryos, neonates, subadult and adult females, demonstrated that in Torpedo marmorata oogenesis occurs very early in life and continues, in its proliferative phase, also after birth. Clusters of early meiotic cells were already evident in the ovarian cortex of 6-cm-long embryos, as well as in the ovary of newborns and three-month-old young. Conversely, in the ovaries of subadult and adult females, all the germ cells present were organized into follicles, and no clusters of oogonia and early meiotic cells were generally found in the cortex, except for one adult female where clusters of germ cells not organized in follicles were found in the cortex. These data demonstrated that, in Torpedo marmorata, oogenesis is immediate, and, as oogonia persist after birth, more similar to that of mouse, monkey, rabbit, and ferret (Mauleon Arch Anat Microsc, 1967; 56:125-150;Byskov and Hoyer 1994) than to that of human, rat, pig, and guinea pig (Byskov and Hoyer 1994). Such a pattern is in agreement with the reproductive strategy of Torpedo, a scantly prolific species with low uterine fecundity. The presence of meiotic cells that are not organized in follicles in one adult female might be consistent with the large individual variability characterizing cartilaginous fishes. The possibility that such a character is typical of mature females should be rejected as oogonia and early meiotic cells were not found inside the totally sectioned gonads of subadult and adult females.

show abstract

“…Garnier and Sourdaine (1990) have observed a rise in sperm production, from March to May and in August, when compared to the rest of the year. Finally, in S. tiburo, spermatogenesis begins in May or June and spermatocysts containing spermatozoa are observed in August (Parsons and Grier, 1992).…”

Section: Testicular Structurementioning

confidence: 98%

Cell‐cell interactions in the testis of teleosts and elasmobranchs

Loir¹,

Sourdaine²,

Mendis‐Handagama³

et al. 1995

Microscopy Res & Technique

View full text Add to dashboard Cite

In this paper we present the state of knowledge on cell-cell interactions in the testis of two groups of anamniote vertebrates--teleosts and elasmobranchs--which include most fish. In these fish, the structural organization of the testis differs fundamentally from that which characterizes amniotes in which the germinal tissue is located in tubules open at both ends and consists of a permanent population of Sertoli cells associated with successive stages of germ cell development. In fish, the spermatogenic unit of testis is the spermatocyst, which corresponds to one germ cell or to a clone of isogenetic germ cells, enclosed by one or several Sertoli cells, which form the wall of the cyst. In fish testis, the Sertoli cells do not represent a permanent population of cells. Although both are of the cystic type, the teleost and elasmobranch testes are differently organized. In elasmobranchs, primary spermatogonia and Sertoli cells lie initially free within the interstitial tissue, before becoming sequestered by a basement membrane; the testis is then composed of a mass of spermatocysts which contain many Sertoli cells, each being associated with a clone of germ cells. In contrast, in teleosts, the cysts are confined to large elongated structures limited by a basement membrane. These structures are either lobules originating under the albuginea or tubules which, in contrast to those of mammals, are anastomosed. In the lobules, the spermatocysts start to develop at the blind end of the lobules and migrate towards the efferent system, whereas in the tubules, the spermatocysts are located against the basement membrane, all along the tubules and do not migrate. In elasmobranchs, unlike teleosts, Leydig cells are either absent from the interstitial tissue or rare and undifferentiated and their role in steroid production is at best marginal. While many studies have focused on topographical and functional interactions between the diverse cell types present in mammalian testis, only a few studies have brought particular attention to these aspects in fish. In fish, like in mammals, testicular cell-cell interactions are based on structural elements and chemical factors. Occasionally, various adhering junctions have been observed, essentially in teleosts, between Sertoli cells, between Sertoli cells and germ cells, between germ cells themselves, and interstitial cells. Furthermore, in some teleost species, using horseradish peroxidase or lanthanum salts, the presence of tight junctions between Sertoli cells has been correlated to the occurrence of a Sertoli barrier. In these species, the barrier develops after meiosis so that only haploid germ cells are shielded from the vascular system. In fish, recent development of techniques which enable the preparation and in vitro culture of enriched populations of testicular cells and of spermatocysts, has allowed investigations on functional aspects of cell-cell interactions. In particular, data have been obtained, in the trout, on the control of spermatogonia proliferation by Sertoli cel...

show abstract

Seasonal changes in shark testicular structure and spermatogenesis

Cited by 89 publications

References 23 publications

Morphology and dynamics of male gametogenesis in Sympterygia bonapartii (Chondrichthyes, Rajidae) from Northern Patagonia

Morphology and dynamics of male gametogenesis in Sympterygia bonapartii (Chondrichthyes, Rajidae) from Northern Patagonia

An ultrastructural study of germ cells during ovarian differentiation in Torpedo marmorata

Cell‐cell interactions in the testis of teleosts and elasmobranchs

Contact Info

Product

Resources

About