Influences of environmental factors and pineal gland on seasonal testicular cycle in white‐throated munia(Lonchura malabarica)

Abstract

Abstract Histological studies of the seasonal testicular cycle in white‐throated munia, Lonchura malabarica (Passeriformes : Ploceidae) Tevealed that this bird breeds from September to January in India. The gametogenesis in the male gonad starts in May when the day length is maximum and the temperature high. The initiation of sexual cycle starts in May‐July. Active spermatogenesis occurs in September to October. The Leydig cell nucleus diameter increases in August just before the onset of spermatogenesis. The diameter of pinealocyte nucleus increases in non‐breeding stage of the bird and decreases during breeding period.