Table 2 Description of the gametogenic stages of females and males
From: Growth, mortality, and reproduction of Tagelus plebeius (Bivalvia: Solecurtidae) in Southeast Brazil
Stage | Brief description of gonad | Figures |
|---|---|---|
Female | ||
Early gametogenesis | The connective tissue is abundant, the size of the follicles is small, and the initial stage of gametogenesis is present. Oocytes lie at the periphery of the gonadal walls and are attached to the basal membrane by a stalk | 5a |
Late gametogenesis | The size of the follicles increased and the initial stage of gametogenesis is still present, but restricted to the periphery of the follicles. Most mature oocytes are free in the lumina while some are still attached to the basal membrane by a thin stalk | 5b |
Ripe | The connective tissue has been reduced by the enlargement of the follicles by ripe gametes. The mature oocytes take polygonal shape due to packing. A decrease in the percentage of oogonia and pre-vitellogenic oocytes attached to the wall was also seen | 5c |
Spawning | Gametes are being released and empty spaces were observed in the follicular lumina | 5d |
Spent | The follicle lies empty with occasional residual oocytes present | 5e |
Male | ||
Gametogenesis | The connective tissue is abundant, and the size of the follicles is small. Spermatocytes proliferate toward the lumina, and rows of germinal cells in phases of maturation (spermatogonias, spermatocytes, and spermatids) form a germinal layer near the gonadal wall | 6a |
Ripe | The connective tissue has been reduced by the enlargement of the follicles by ripe gametes. Lumina is packed with ripe spermatozoa. | 6b |
Spawning | Follicles showed a radial arrangement of the spermatozoa as they are being released | 6c |