Biology Faculty Articles

Semen Characteristics in Free-Living Koalas (Phascolarctos cinereus)

ORCID

0000-0001-7353-8301

ResearcherID

N-1726-2015

Document Type

Article

Publication Title

Journal of Reproduction and Fertility

ISSN

0022-4251

Publication Date

5-1-1991

Keywords

Koala, Marsupial, Semen, Electroejaculation, Spermatozoa, Testis, Testosterone

Abstract

Spermic electroejaculates (range in motile sperm/ejaculate, 0.50–122.9 × 106; mean ± s.e.m., 38.6 ± 4.9) were recovered from 47 of 48 adult koalas captured from 3 wild populations in Australia. Semen was characterized by (i) a high density of globular bodies, which prevented the estimation of sperm motility without dilution; (ii) a brownish colour; and (iii) an acidic pH. Spermatozoa were categorized on the basis of 10 head forms, most cells being a curved or hooked shape. The koala populations differed in sperm concentration and motility ratings, but not in testes size, testosterone production or proportions of spermatozoa with various head shapes. These data confirm that free-living koalas normally produce spermatozoa with a high incidence of structural heterogeneity almost solely confined to the head region; and demonstrate the utility and safety of conventional gamete and endocrine studies, approaches which will be useful for determining the impact of genetic isolation and venereal disease on species fertility.

Volume

92

Issue

1

First Page

99

Last Page

107

Comments

©1991 Journals of Reproduction & Fertility Ltd

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