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- Life history of Bathyraja trachura from the eastern Bering Sea, with evidence of latitudinal variation in a deep-sea skate species
- Although many skates possess life history characteristics that may make them vulnerable to exploitation, the detailed biological information needed to enact effective management schemes is lacking for most species. The objectives of this study were to provide age, growth, and maturity estimates for the roughtail skate, Bathyraja trachura, from the eastern Bering Sea. Maximum age was estimated at 36 yr based on band pair counts in vertebral centra. Of the four growth models applied, the logistic model provided the best description of growth (asymptotic total length = 911 mm; growth coefficient = 0.131 yr-1). There was no evidence of difference in growth between males and females. Females attained maturity at larger sizes and older ages than males. The median size-at-maturity was estimated at 741 mm total length (TL) for males and 796 mm TL for females; median age-at-maturity was estimated at 21.1 yr and 24.7 yr for males and females, respectively. The results of this study may indicate a latitudinal pattern in size and growth, with individuals from the eastern Bering Sea growing more slowly and reaching higher maximum ages than previously reported for specimens collected off the western coast of the continental United States. Copyright © Marine Biological Association of the United Kingdom 2013., Fish and Fisheries, Downloaded from: http://journals.cambridge.org/action/displayFulltext?type=1&fid=9155760&jid=MBI&volumeId=94&issueId=02&aid=9155757 (9 June 2014).
- Winton, Natanson, Kneebone, Cailliet, Ebert
- Age and growth characteristics of the Starry Skate, Raja stellulata, with a description of life history and habitat trends of the central California, U.S.A., skate assemblage
- Skates are prevalent in fisheries worldwide, but rarely are they identified to species. This is of conservation and management concern since skates exhibit a broad range of life history characteristics. The present study investigated the age and growth of the Starry Skate, Raja stellulata, and compared it to other regional skates inhabiting the U.S. West Coast. Age and growth parameters were determined using two vertebral preparation techniques: gross sectioning and histological sectioning. Gross section age estimates ranged from zero to 11 years and growth was described by the two parameter von Bertalanffy growth function (2 VBGF; L ∞ = 915 mm total length (TL) and k = 0.13 year-1; n = 189). Histological section age estimates ranged from zero to 15 years and growth was also described by the 2 VBGF (L ∞ = 1092 mm TL, k = 0.06 year-1; n = 68). Histological section results reflect a more conservative life history, specifically a lower von Bertalanffy growth coefficient, but had slightly biased results and a smaller sample size than the gross section results. An age and depth trend was found within the central California skate assemblage, in which habitat depth and maximum age were positively correlated. © 2013 Springer Science+Business Media Dordrecht., Fish and Fisheries
- James, Ebert, Natanson, Cailliet