U.S. flag An official website of the United States government.
Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS

A lock ( ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

i

Serum estradiol and progesterone profiles during estrus, pseudopregnancy, and active gestation in Steller sea lions



Details

  • Journal Title:
    Zoo Biology
  • Personal Author:
  • NOAA Program & Office:
    NMFS (National Marine Fisheries Service)
  • Description:
    While the proximate driver behind the decline of the Western stock of Steller sea lions (Eumetopias jubatus, >80% since 1970s) is likely multifactorial, the population reduction may have been powered by a decrease in fecundity. A harvest of Steller sea lions in the 1970s and 80s revealed a 30% reduction in the proportion of pregnant females from early (October–November) to late gestation (April–May). Identification and quantification of these reproductive failures are difficult when we lack species‐specific data on endocrinology associated with discrete stages of the reproductive cycle (i.e., estrus, implantation, and gestation). We tracked changes in serum estradiol and progesterone in three adult female Steller sea lions from 2011 to 2015. In all years and most females, a discrete increase in estradiol was observed during the breeding season (June–August), indicative of estrus. Estradiol concentrations from October to May in a pregnant female compared to her corresponding values when non‐pregnant did not consistently differ through gestation. An elevation in progesterone was observed in all females and all years beginning approximately in June and lasting through November. This likely results from progesterone production by the corpus luteum in both pregnant and pseudopregnant females. Serum progesterone shows promise as a diagnostic tool to identify pregnancy during months 3–5 (December–February) of the 8‐month active gestation following embryonic implantation. This study provides ranges of key hormones during estrus, embryonic diapause/pseudopregnancy, and gestation in pregnant and non‐pregnant females for studying reproduction in Steller sea lions.
  • Keywords:
  • Source:
    Zoo Biology, 36(5), 323-331
  • DOI:
  • ISSN:
    0733-3188 ; 1098-2361
  • Format:
    PDF
  • Publisher:
    Wiley
  • Document Type:
    Journal Article
  • Funding:
    Grant no. NA12NMF4390066
  • Rights Information:
    Accepted Manuscript
  • Compliance:
    Library
  • Main Document Checksum:
    urn:sha256:49a23f257330d940032c61518f4224dcbc58faaa74ef8deb8b528c8ede5b3ada
  • Download URL:
  • File Type:
    Filetype[PDF - 540.66 KB ]
PREVIOUS
ON THIS PAGE
Details
The NOAA IR serves as an archival repository of NOAA-published products including scientific findings, journal articles, guidelines, recommendations, or other information authored or co-authored by NOAA or funded partners. As a repository, the NOAA IR retains documents in their original published format to ensure public access to scientific information.
BACK TO TOP