Age, growth and maturity of the roundel skate, Raja texana, from the Gulf of Mexico, USA
James A. Sulikowski A D E , Sarah B. Irvine B , Kate C. DeValerio A and John K. Carlson CA Florida Program for Shark Research, Florida Museum of Natural History, University of Florida, PO Box 117800, Gainesville, FL 32611, USA.
B Department of Fisheries, Western Australia.Level 3, The Atrium, 168 St Georges Terrace, Perth, WA 6001, Australia.
C NOAA Fisheries Panama City Laboratory, 3500 Delwood Beach Road, Panama City, FL 32408, USA.
D Present address: Marine Science Center University of New England, 11 Hills Beach Rd, Biddeford, ME 04005, USA.
E Corresponding author. Email: jsulikowski@une.edu
Marine and Freshwater Research 58(1) 41-53 https://doi.org/10.1071/MF06048
Submitted: 21 March 2006 Accepted: 6 October 2006 Published: 30 January 2007
Abstract
The roundel skate (Raja texana) inhabits near-shore waters throughout the Gulf of Mexico. Despite such a wide distribution, very little is known about its biology. In order to gain insight into the life history of this species, the age, growth and maturity of 231 skates ranging in size from 277 to 630-mm total length (TL) were examined. Based on vertebral band counts, the oldest age estimates obtained were 8 years for males and 9 for females, which corresponded to 495-mm TL and 630-mm TL respectively. Age-bias plots and coefficient of variation suggested that our ageing method represents a non-biased and precise approach to age assessment. Marginal increment and edge analyses suggested that growth bands are formed annually with a distinct trend of increasing growth at the beginning of March. Back calculations suggested a birth size of 113–118-mm TL. Observed and back-calculated length-at-age data were used to assess growth with four different models, including the von Bertalanffy (VBGM), von Bertalanffy with size at birth (VB with L 0), Gompertz and Francis models. Male and female growth was significantly different. The VBGM and the Francis model produced similar results and provided the best fit. Curves fitted with observed and back-calculated data suggested slightly faster growth than curves fitted with only observed data. Maturity occurred at 444-mm TL and 4.95 years for males, whereas females matured at 537-mm TL and 5.8 years.
Additional keywords: elasmobranch, marginal increments, Rajiformes, shell gland, spermatocyst.
Acknowledgements
We would like to thank Dana Bethea (NOAA Fisheries Panama City Laboratory), Kim Johnson and Andre Debose (NOAA Fisheries Pascagoula Laboratory) for help in collection of skates. Thanks are further extended to Travis Ford for help in the biological processing. This study was supported by funds from NOAA/NMFS to the National Shark Research Consortium.
Beamish, R. J. , and Fournier, D. A. (1981). A method for comparing the precision of a set of age determinations. Canadian Journal of Fisheries and Aquatic Sciences 38, 982–983.
Branstetter, S. (1987). Age and growth-estimates for blacktip, Carcharhinus limbatus, and spinner, C. brevipinna, sharks from the northwestern Gulf of Mexico. Copeia 1987, 964–974.
| Crossref | GoogleScholarGoogle Scholar |
Casey, J. M. , and Myers, R. A. (1998). Near extinction of a large widely distributed fish. Science 281, 690–692.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Campana, S. E. (2001). Accuracy, precision and quality control in age determination including a review of the use and abuse of age validation methods. Journal of Fish Biology 59, 197–242.
| Crossref | GoogleScholarGoogle Scholar |
Dulvy, N. K. , and Reynolds, J. D. (2002). Predicting extinction vulnerability in skates. Conservation Biology 16, 440–450.
| Crossref | GoogleScholarGoogle Scholar |
Francis, M. P. , and Ó Maolagáin, C. (2005). Age and growth of the Antarctic skate (Amblyraja georgiana) in the Ross Sea. CCAMLR Science 12, 183–194.
Goldman, K. J. , and Musick, J. A. (2006). Growth and maturity of salmon sharks in the eastern and western North Pacific, and comments on back-calculation methods. Fishery Bulletin 104, 278–292.
Irvine, S. B. , Stevens, J. D. , and Laurenson, L. J. B. (2006a). Surface bands on deepwater squalid dorsal-fin spines: an alternative method for ageing Centroselachus crepidater. Canadian Journal of Fisheries and Aquatic Sciences 63, 617–627.
| Crossref | GoogleScholarGoogle Scholar |
Mollet, H. F. , Ezcurra, J. M. , and O'Sullivan, J. B. (2002). Captive biology of the pelagic stingray, Dasyatis violacea (Bonaparte, 1832). Marine and Freshwater Research 53, 531–541.
| Crossref | GoogleScholarGoogle Scholar |
Natanson, L. J. , Mello, J. J. , and Campana, S. E. (2002). Validated age and growth of the porbeagle shark (Lamna nasus) in the western North Atlantic Ocean. Fishery Bulletin 100, 266–278.
Ricker, W. E. (1975). Computation and interpretation of biological statistics of fish populations. Bulletin of the Fisheries Research Board of Canada 191, 1–382.
Rogers, C. , Roden, C. , Lohoefener, R. , Mullin, K. , and Hoggard, W. (1990). Behavior, distribution, and relative abundance of cownose ray schools Rhinoptera bonasus in the northern Gulf of Mexico. Northeast Gulf Science 11, 69–76.
Stevens, J. D. , Bonfil, R. , Dulvy, N. K. , and Walker, P. A. (2000). The effects of fishing on sharks, rays, and chimaeras (chondrichthyans), and the implications for marine ecosystems. ICES Journal of Marine Science 57(3), 476–494.
| Crossref | GoogleScholarGoogle Scholar |