eCite Digital Repository

Asynchronous male and female gonadal cycles and plasma steroid concentrations in a viviparous lizard, Niveoscincus ocellatus (Scincidae), from Tasmania

Citation

Jones, SM and Wapstra, E and Swain, R, Asynchronous male and female gonadal cycles and plasma steroid concentrations in a viviparous lizard, Niveoscincus ocellatus (Scincidae), from Tasmania, General and Comparative Endocrinology, 108, (2) pp. 271-281. ISSN 0016-6480 (1997) [Refereed Article]

DOI: doi:10.1006/gcen.1997.6971

Abstract

The reproductive cycle in males of the skink, Niveoscincus ocellatus, is characterised by testicular development during summer, followed by mating in autumn. Plasma testosterone concentrations show a bimodal seasonal cycle, with the major peak (18.6 1.2 ng/ml) in late summer/autumn and a minor peak (7.4 1.0 ng/ml) at spring emergence. In contrast to the males, the females have a gonadal cycle in which mating is temporally dissociated from peak development of the gonads: ovulation occurs in spring and the young are born in summer. Fresh mating marks on females in spring indicate that at least part of the population mates for a second time after spring emergence. In females, plasma estradiol concentrations are significantly elevated (956 214 pg/ml) through vitellogenesis and are highest (1241 175 pg/ml) during the preovulatory phase. Plasma progesterone concentrations rise during gestation to 6.5 1.5 ng/ml, but fall in the final stage of gestation to 1.6 0.2 ng/ml. There is minimal atresia of vitellogenic follicles, suggesting that clutch size is determined when the follicles are recruited for vitellogenesis.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Zoology
Research Field:Zoology not elsewhere classified
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Environmental Sciences
Author:Jones, SM (Professor Susan Jones)
Author:Wapstra, E (Associate Professor Erik Wapstra)
Author:Swain, R (Dr Roy Swain)
ID Code:11086
Year Published:1997
Web of Science® Times Cited:57
Deposited By:Zoology
Deposited On:1997-08-01
Last Modified:2014-04-17
Downloads:0

Repository Staff Only: item control page