Spermatogenesis and changes in testicular structure during the reproductive cycle in Cichlasoma dimerus (Teleostei, Perciformes)

Abstract

Rey Vázquez, G., Da Cuña, R.H., Meijide, F.J., and Guerrero, G.A. 2012. Spermatogenesis and changes in testicular structure during the reproductive cycle in Cichlasoma dimerus (Teleostei, Perciformes). -Acta Zoologica (Stockholm) 93: 338-350.The present study aimed at analyzing spermatogenesis and the changes occurring in the testis throughout the reproductive cycle in the South American perciform fish Cichlasoma dimerus. Testes were studied using light and electron microscopy techniques. This species has an unrestricted lobular testis composed of two compartments: germinal, containing Sertoli and germ cells, exhibiting a cystic mode of spermatogenesis; and interstitial, composed of Leydig cells and connective tissue elements. Spermatozoa belong to the anacrosomal type I aquasperm and possess two flagella, this being the first report of an externally fertilizing cichlid exhibiting biflagellate sperm. Under laboratory conditions, C. dimerus proved to be a multiple spawner throughout the year, with a season of higher reproductive activity extending from September to March, during which fish spawned on average every 29.4 days. Changes in the germinal epithelium and the germ cell stages present allowed the description of five reproductive classes: regressed, early, mid-, and late maturation, and regression. During the high reproductive season, each cycle went through the first four classes. The regressed class overlapped with the late maturation class, because sperm was being released while spermatogonia were proliferating. The regression class occurred solely in sexually inactive males during the period of low reproductive activity.

Morphological evidence for a permeability barrier in the testis and spermatic duct ofGymnotus carapo(Teleostei: Gymnotidae)

“…The testicular parenchyma of G. carapo displayed the germinal and interstitial compartments described in all vertebrates. As in other teleost fish (Nobrega and Quagio‐Grassiotto, ; Vazquez et al, ), the seminiferous tubules of this species contained spermatogenic cysts formed by Sertoli cells that envelop a group of synchronously developing germ cells. Histologically, the testis of G. carapo seem to correspond to the unrestricted spermatogonial testicular type, found in most teleosts, where spermatogonia reside along the testicular tubules (Grier et al, ; Grier, ).…”

A multidisciplinary study on social status and the relationship between inter-individual variation in hormone levels and agonistic behavior in a Neotropical cichlid fish

“…In a pilot study, 60 points proved sufficient to adequately determine the percentage of all cell types (we tested 45, 60, 75 and 90 points; p>0.05 for 60, 75 and 90). We followed the detailed histological description of C. dimerus testis by Rey Vázquez et al (2012) to correctly identify each cell type. Thereafter we calculated the percentage of type A and B spermatogonia, spermatocytes (primary and secondary combined), spermatids, spermatozoa and interstitial tissue.…”

Ultrastructural analysis of spermiogenesis in the neotropical cichlidCichla kelberiKullander & Ferreira, 2006 (Perciformes: Cichlidae)

“…Both types are present in the Perciform Order, however, the Type II is the most frequent, occurring in 29 from the 41 studied family, giving it the name of perciform spermatozoon (Mattei, ; Jamieson, ; Mattei, ; Abascal et al., ; Jamieson, ). However, against this tendency, the most species of the Cichlidae family, including C. kelberi in the present study, present the Type I (Mattei, ; Cruz‐Landim and Cruz‐Hofling, ; Jamieson, ; Silva and Godinho, ; Matos et al., ; Quagio‐Grassiotto et al., ; Jamieson, ; Vázquez et al., ).…”

“…Going on with Perciform, some of its representative can form one, two or even three lateral expansions from the flagellar membrane called ‘fins’ (Jamieson, ; Mattei, ). In the cichlids, as in C. kelberi, the fins are present in a pair, with lengths which vary according the specie (Cruz‐Landim and Cruz‐Hofling, ; Jamieson, ; Silva and Godinho, ; Matos et al., , ; Quagio‐Grassiotto et al., ; Vázquez et al., ). Nevertheless, it isn't one common family characteristic, because according Jamieson (), this structure was not observed in 13 species of Cichlidae, including some studied by Fishelson ().…”

“…Besides this three characteristic, the presence of cytoplasmic sheath and flagellum fins, observed in the C. kelberi spermatozoon, also are present isolated or together in some Cichlidae family representative (Cruz‐Landim and Cruz‐Hofling, ; Jamieson, ; Silva and Godinho, ; Matos et al., , ; Quagio‐Grassiotto et al., ; Vázquez et al., ), so, it can't be considered exclusive to the group. However all representative spermatozoon of Cichla genus described until this moment, present both the structure observed (Cruz‐Landim and Cruz‐Hofling, ; Quagio‐Grassiotto et al., ).…”