Reproductive parameters of surviving 'die-off' male Antechinus flavipes and Antechinus stuartii (Dasyuridae : Marsupialia) in their second year of life

Abstract

Males of the genus Antechinus (Dasyuromorphia) undergo dramatic behavioural, physical and physiological change that results in complete male mortality after the mating period. Occasionally, males in the wild survive longer than this immediate post-mating period, and post ‘die-off’ survivorship for a second year has also been documented in captivity. The present study sought to quantify changes in the physiology and behaviour of male A. flavipes and A. stuartii that survive through a second year of life. Males from both species never demonstrated spermatorrhoea in their second year, although secondary sexual characteristics and sexual behaviour were recovered in their second year. Thus, the seminiferous tubular collapse seen before the mating period in their first year of life is irreversible and complete, although the cycling of other sexual characteristics suggests that the hypothalamic-pituitary-gonadal pathways and function of the interstitial cells of the testes are retrievable.