Document Detail


Seasonal reproduction of female round stingrays (Urobatis halleri): steroid hormone profiles and assessing reproductive state.
MedLine Citation:
PMID:  20015450     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
This study characterizes the seasonal reproductive cycle of female round stingrays (Urobatis halleri) in an open coastal site at Seal Beach, CA and a protected estuary at the Seal Beach National Wildlife Refuge (SBNWR). Female round stingrays were sampled from August 2004 to July 2006, and assessed for reproductive parameters (GSI, maximum ova diameter, pregnancy status) and sex steroid (estradiol (E(2)), progesterone (P(4)) and testosterone (T)) concentrations. E(2) and P(4) increased at the time of ovulation (June and July) and remained elevated until parturition (October and November); recently partruded females were observed until November. Mature females were absent from Seal Beach in August and September, the same time period that abundance of mature females peaked in the SBNWR. This aggregation of predominantly mature females in the upper reaches of the SBNWR was seasonal, and was observed from April to September. To better understand the aggregation behavior, sex steroid hormones were assayed in SBNWR females. In July and August, E(2) and P(4) concentrations in females at the SBNWR were 1.5-fold and 2-fold higher, respectively, than concentrations in mature females at Seal Beach, and correlated with elevated water temperature in the estuary. Pregnancy was confirmed in aggregating females by increased levels of E(2) and P(4) and the presence of developing embryos. Our data suggest that coastal estuaries may play a crucial role in round stingray reproduction, perhaps by providing a thermal refuge for pregnant females during gestation.
Authors:
Christopher G Mull; Christopher G Lowe; Kelly A Young
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2009-12-14
Journal Detail:
Title:  General and comparative endocrinology     Volume:  166     ISSN:  1095-6840     ISO Abbreviation:  Gen. Comp. Endocrinol.     Publication Date:  2010 Apr 
Date Detail:
Created Date:  2010-03-08     Completed Date:  2010-05-24     Revised Date:  2010-06-16    
Medline Journal Info:
Nlm Unique ID:  0370735     Medline TA:  Gen Comp Endocrinol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  379-87     Citation Subset:  IM    
Copyright Information:
(c) 2009 Elsevier Inc. All rights reserved.
Affiliation:
Department of Biological Sciences, California State University Long Beach, Long Beach, CA 90840, USA. cmull@sfu.ca
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MeSH Terms
Descriptor/Qualifier:
Animals
Behavior, Animal
Elasmobranchii / physiology*
Estradiol / blood
Female
Ovary / anatomy & histology,  physiology
Progesterone / blood
Reproduction / physiology*
Seasons*
Testosterone / blood
Chemical
Reg. No./Substance:
50-28-2/Estradiol; 57-83-0/Progesterone; 58-22-0/Testosterone

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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