. Bulletin - Southern California Academy of Sciences. Science. CLASSIFICATION OF GONAD MACROSTRUCTURE IN CALIFORNIA SHEEPHEAD 23. Fig. 3. Representative photographs of male California Sheephead testicular development. Bars in the lower left corner of each photo represent 100 micrometers. Inset bars in (A) and (D) represent 400 micrometers and 50 micrometers, respectively. (A) During the earliest noted transition class very high levels of atretic follicles are noted, few early stage oocytes, and massive tissue reorganization. (B) As the transition progresses, spermatogonia and primary spermatoc
. Bulletin - Southern California Academy of Sciences. Science. CLASSIFICATION OF GONAD MACROSTRUCTURE IN CALIFORNIA SHEEPHEAD 23. Fig. 3. Representative photographs of male California Sheephead testicular development. Bars in the lower left corner of each photo represent 100 micrometers. Inset bars in (A) and (D) represent 400 micrometers and 50 micrometers, respectively. (A) During the earliest noted transition class very high levels of atretic follicles are noted, few early stage oocytes, and massive tissue reorganization. (B) As the transition progresses, spermatogonia and primary spermatocytes can be observed among early stage oocytes. (C) In late transition, early stage oocytes are very rare, with further stages of spermatogenesis noted. (D) Active males commonly exhibit the final stages of spermatogenesis. (E) Inactive males contain mostly residual spermatocytes and early stage spermatogenic tissue. AT = atretic follicle. CO = chromatin nucleolar oocyte. RSG = residual spermatocyte. SG = spermatagonia. ST = spermatid. 1SY = primary spermatocyte. 2SY = secondary spermatocyte. SZ = spermatozoa. functional as male. In addition, primary stage oocytes were no longer found in the gonads of fish classified as late transitional, although oocyte atresia was still apparent (Figure 3C). Gonads of fish classified as mature males showed no residual atretic follicles (Figure 3D). During the summer breeding months, the male gonad was characterized by dense spermatocysts of all developmental stages (, Figure 3D); while during the winter non-breeding months the mature male testis contained mainly spermatogonia, residual spermatozoa, and some primary spermatocytes (Figure 3E). Hormone Concentrations No measurable levels of E2 were detected in most transitional individuals or in males. Concentrations of E2 differed significantly by season 0F3,9o = , p = ) and by gender CF2,9o= P < ; Figure 4A). There was no difference in E2 concentrations. Please note that
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