The annual reproductive behaviour of the green frog, Rana hexadactyla Lesson, in and around Mangalore and Mysore city (India)

Abstract

The annual reproductive behaviour of the frog, Rana hexadactyla, was studied from two climatologically contrasting regions and correlated with the environmental conditions, like temperature, relative humidity and rainfall prevailing there. Since some data were available on the gonadal activity of this species from two other areas, they were also considered. The results show that the gametogenic activity is under the marked influence of the range of temperature and relative humidity prevailing in the locality while the pattern of rainfall plays a supplementary role. The activity begins sometime in March or April when the locality experiences the pre-monsoon (south west) showers. The gametogenesis occurs rapidly around Mangalore where the range of temperature between the monthly mean maximum and the minimum is narrow and stable from April to October but in Mysore city similar environmental conditions are seen from June to October and the gametogenesis becomes active during this period. Thus, ovulation and oviposition take place during June or July at Mangalore whereas the same occur towards the end of August at Mysore city.