Seminal characteristics and spermatozoal morphology of captive Queensland koalas (Phascolarctos cinereus adustus).

Viable koala spermatozoa were successfully collected from 8 of 11 captive Queensland koalas on 52 of 76 attempts using electroejaculation under general anesthesia. Semen characteristics, including sperm concentration, percent progressive sperm motility and nuclear heterogeneity appeared to be similar to those of free-ranging Victoria koalas (P.c . victor). Two new head morphotypes (Type XI and teratoid) were identified, and the incidence of midpiece and principal piece spermatozoal abnormalities were recorded.