University of Tasmania
Browse

Endocrine control of embryonic diapause in the Australian sharpnose shark Rhizoprionodon taylori

Download (839.49 kB)
journal contribution
posted on 2023-05-18, 02:51 authored by Waltrick, D, Jones, SM, Simpfendorfer, CA, Cynthia AwruchCynthia Awruch
The reproductive cycle of the Australian sharpnose shark, Rhizoprionodon taylori, includes a temporary suspension of development at the commencement of embryogenesis termed embryonic diapause. This study investigated levels of 17βestradiol (E2), testosterone (T) and progesterone (P4) in plasma samples of mature wild female R. taylori captured throughout the reproductive cycle and correlated them with internal morphological changes. Levels of T were elevated through most of the embryonic diapause period, suggesting a role of this hormone in the maintenance of this condition. Increasing plasma T concentrations from late diapause to early active development were associated with a possible role of androgens in the termination of embryonic diapause. As in other elasmobranchs, a concomitant increase of E2 with ovarian follicle size indicated a direct role of this hormone in regulating vitellogenesis, while a peak in P4 suggested this hormone is associated with preovulation and ovulation. Additionally, significant correlations between photoperiod or water temperature and maximum follicular diameter and hepatosomatic index suggest that these abiotic factors may also play a role triggering and regulating the synchrony and timing of reproductive events.

Funding

Winifred Violet Scott Charitable Trust

History

Publication title

PLoS One

Volume

9

Issue

7

Article number

e101234

Number

e101234

Pagination

1-10

ISSN

1932-6203

Department/School

School of Nursing

Publisher

Public Library of Science

Place of publication

USA

Rights statement

Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) http://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Marine biodiversity

Usage metrics

    University Of Tasmania

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC