eCite Digital Repository

Delayed ovulation and parturition in a viviparous alpine lizard (Niveoscincus microlepidotus): morphological data and plasma steroid concentrations

Citation

Girling, JE and Jones, SM and Swain, R, Delayed ovulation and parturition in a viviparous alpine lizard (Niveoscincus microlepidotus): morphological data and plasma steroid concentrations, Reproduction Fertility and Development, 14, (1) pp. 43-53. ISSN 1031-3613 (2002) [Refereed Article]

DOI: doi:10.1071/RD01091

Abstract

The southern snow skink, Niveoscincus microlepidotus, exhibits an unusual biennial reproductive cycle with an extended gestation period of approximately 1 year. Morphological data were gathered on a monthly basis, providing a detailed picture of the reproductive cycle. Vitellogenesis begins in spring, immediately after parturition. Maximum follicular diameter is reached before the winter hibernation period and ovulation occurs the following spring. Embryos are fully developed and reach maximum size by early autumn. Yolk reserves are depleted before winter. Birth of between one and four young occurs the following spring. Plasma progesterone concentrations are low (2.7 0.9 ng mL1) in post-partum females, begin to rise in autumn in vitellogenic females and peak (38.5 7.9 ng mL1) in pre-ovulatory females after hibernation. Concentrations are high (15.4 5.9 ng mL1) in early pregnancy and decline to basal levels before winter and well before birth in spring. Plasma oestradiol concentrations peak during vitellogenesis (1.0 0.3 ng mL1) and decline to basal levels during pregnancy (0.2 0.03 ng mL1). A second oestradiol peak occurs before parturition (0.7 0.2 ng mL1). Thus, functional completion of vitellogenesis and gestation is achieved by autumn in successive years. The mechanisms that defer ovulation and parturition by a further six months are unknown.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Physiology
Research Field:Comparative Physiology
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Forest and Woodlands Flora, Fauna and Biodiversity
Author:Girling, JE (Dr Jane Girling)
Author:Jones, SM (Professor Susan Jones)
Author:Swain, R (Dr Roy Swain)
ID Code:24582
Year Published:2002
Web of Science® Times Cited:19
Deposited By:Zoology
Deposited On:2002-08-01
Last Modified:2014-04-17
Downloads:0

Repository Staff Only: item control page