Reproduction in males of the feathertail glider Acrobates pygmaeus (Marsupialia)

Between 1984 and 1986, reproductive tracts were collected from 17 male Acrobates pygmaeus (Shaw) from south-eastern Australia and the anatomy of these tracts is described. The prostate is heart-shaped and the arrangement of its three segments, anterior, central and posterior, is different to the patterns described for other marsupials. The testes are large in proportion to the body size but their structure and that of the remainder of the tract is typical of other marsupials. The sperm morphology is similar to that of the Phalangeridae and Burramyidae.
Seasonal cycles were found in the sizes of testes and prostates. Increases in testes sizes, starting in April or May, were associated with increases in seminiferous tubule diameter and Leydig cell size. The weight of the prostate increased rapidly to a short peak in June when the testes also reached maximum weight. The first births occurred approximately one month later in this population. Following this peak, both the testes and the prostate decreased in size and had returned to the original weights by January. The beginning of this period when the testes and prostate were small coincided with the cessation of births in the population and was marked by an interruption in spermatogenesis.
Males born early in a breeding season mature before the start of the next breeding season, but males born at the end of a breeding season may not mature until the second season after their birth, at which time they are approximately 18 months of age.