Verification of sex from harvested sea otters using DNA testing

Wildlife Society Bulletin
By: , and 



We used molecular genetic methods to determine the sex of 138 sea otters (Enhydra lutris) harvested from 3 regions of Alaska from 1994 to 1997, to assess the accuracy of post‐harvest field‐sexing. We also tested each of a series of factors associated with errors in field‐sexing of sea otters, including male or female bias, age‐class bias, regional bias, and bias associated with hunt characteristics. Blind control results indicated that sex was determined with 100% accuracy using polymerase chain reaction (PCR) amplification using primers that co‐amplify the zinc finger‐Y‐X gene, located on both the mammalian Y‐ and X‐chromosomes, and Testes Determining Factor (TDF), located on the mammalian Y‐chromosome. DNA‐based sexing revealed that 12.3% of the harvested sea otters were incorrectly sexed in the field, with most errors (13 of 17) occurring as males incorrectly reported as females. Thus, female harvest was overestimated. Using logistic regression analysis, we detected no statistical association of incorrect determination of sex in the field with age class, hunt region, or hunt type. The error in field‐sexing appears to be random, at least with respect to the variables evaluated in this study.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Verification of sex from harvested sea otters using DNA testing
Series title Wildlife Society Bulletin
DOI 10.2193/0091-7648(2005)33[1027:VOSFHS]2.0.CO;2
Volume 33
Issue 3
Year Published 2005
Language English
Publisher Wiley
Contributing office(s) Alaska Science Center
Description 6 p.
First page 1027
Last page 1032
Online Only (Y/N) N
Additional Online Files (Y/N) N