Table 1 Histological stages of gonadal sex change in New Zealand spotty wrasse.
From: A new experimental model for the investigation of sequential hermaphroditism
Stage | Abbreviation | Characteristics |
|---|---|---|
Initial phase female | F | Ovary is dominated by healthy oocytes. Depending on season, these may be predominantly previtellogenic stage oocytes or may also include vitellogenic and maturing oocytes. Atretic late-stage oocytes may be common post-spawning |
Early transitioning | ET | Atretic oocytes of all stages, including previtellogenic oocytes, common. Nests of gonial cells, yellow–brown bodies and stromal cells often evident |
Mid-transitioning | MT | Spermatogenic cysts containing mainly spermatogonia or spermatocytes evident. Many atretic oocytes often still present. Stromal cells and cellular debris common |
Late transitioning | LT | Evidence of lobular structure forming. Male germ cells dominate. Yellow–brown bodies and cellular debris common |
Terminal phase male | TP | Fully structured testis with spermatogenic cysts arranged into lobules. Sperm ducts developed peripherally inside the tunica albuginea and presence of central remnant lumen. All stages of spermatogenic germ cells may be present depending on season. A few degenerating oocytes may persist |
Initial phase male | IPM | Presence of lobule formation containing spermatogenic cysts. No evidence of degenerating oocytes. No central lumen and sperm ducts tend to be aggregated centrally |
