Endocrine and Morphological Correlates of Reproduction in the Draughtboard Shark Cephaloscyllium laticeps (Elasmobranchii: Scyliorhinidae)
File version
Author(s)
Pankhurst, Ned W
Frusher, Stewart D
Stevens, John D
Griffith University Author(s)
Primary Supervisor
Other Supervisors
Editor(s)
Date
Size
File type(s)
Location
License
Abstract
This study examined the endocrine and reproductive correlates of reproduction in 636 female and 468 male draughtboard sharks (Cephaloscyllium laticeps) captured from southeastern Australia. Females were oviparous and displayed a single external‐type ovary with a maximum follicle diameter of 35 mm. Vitellogenesis commenced at a follicle diameter of 10 mm. Females showed a constant overlap between follicular recruitment, ovarian growth, and egg laying. The male reproductive tract consisted of paired testes with spermatocysts undergoing diametric development. Plasma levels of the presumptive gonadal steroids, testosterone (T), 17β‐estradiol (E2), progesterone (P4), and 11‐ketotestosterone (11‐KT; males only) were correlated with morphological developmental stages of the gonads. In females, E2 increased as the follicle developed before declining as the follicle reached maturity. T remained low during the first stages of ovarian growth and increased as the follicle reached maturity. P4 showed a peak just before ovulation. In males, T was the only hormone that varied with maturity, increasing in adults; E2 and P4 were present at low plasma concentrations in males and did not change with stage of gonadal development. 11‐KT was undetectable at all times. Endocrine changes in draughtboard sharks were consistent with hormonal correlates reported for other species and suggest roles for E2( in females) and T (in both sexes) in gametogenesis and P4 in maturational events in females. J. Exp. Zool. 309A:184–197, 2008. © 2008 Wiley‐Liss, Inc.
Journal Title
Journal of Experimental Zoology. Part A: Ecological Genetics and Physiology
Conference Title
Book Title
Edition
Volume
309A
Issue
4
Thesis Type
Degree Program
School
Publisher link
DOI
Patent number
Funder(s)
Grant identifier(s)
Rights Statement
Rights Statement
Item Access Status
Note
Access the data
Related item(s)
Subject
Comparative physiology