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Age, growth and reproductive biology of the silky shark, Carcharhinus falciformis, and the scalloped hammerhead, Sphyrna lewini, from the northwestern Gulf of Mexico

Synopsis

The silky shark, Carcharhinus falciformis, and scalloped hammerhead, Sphyrna lewini, represent >80% of the shark by-catch of the winter swordfish/tuna longline fishery of the northwestern Gulf of Mexico. This catch represents a potential supplemental fishery, yet little is known of the life histories of the two species. This report relates reproductive biology data to age and growth estimates for 135 C. falciformis and 78 S. lewini. Unlike other regional populations, C. falciformis in the Gulf of Mexico may have a seasonal 12 month gestation period. Males mature at 210–220 cm TL (6–7 yr); females at >225 cm TL (7–9 yr). Application of age at length data for combined sexes produced von Bertalanffy growth model parameter estimates of L = 291 cm TL, K = 0.153, t0 = −2.2 yr. Adult male S. lewini outnumbered adult females in catches because of differences in the distributions of the sexually segregated population. Males mature at 180 cm TL (10 yr); females at 250 cm TL (15 yr). von Bertalanffy parameter estimates for combined sexes of this species were L = 329 cm TL, K = 0.073, to = −2.2 yr.

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References cited

  • Anderson, E.D. 1985. Analysis of various sources of pelagic shark catches in the northwest and western central Atlantic Ocean and Gulf of Mexico. NOAA Tech. Rep. NMFS 31: 1–14.

    CAS  Google Scholar 

  • Bane, G.W., Jr. 1966. Observations on the silky shark, Carcharhinus falciformis, in the Gulf of Guinea. Copeia 1966: 354–356.

  • Bass, A.J., J.D. D'Aubrey & N. Kistnasamy. 1973. Sharks of the east coast of southern Africa. I. The genus Carcharhinus (Carcharhinidae). Oceanogr. Res. Inst. (Durban), Invest. Rep. 33. 168 pp.

  • Bass, A.J., J.D. D'Aubrey & N. Kistnamy. 1975. Sharks of the east coast of southern Africa. III. The families Carcharhinidae (excluding Carcharhinus and Mustelus) and Sphyrnidae. Oceanogr. Res. Inst. (Durban), Invest. Rep. 38. 100 pp.

  • Branstetter, S. 1981. Biological notes on the sharks of the north central Gulf of Mexico. Contrib. Mar. Sci. 24: 13–34.

    Google Scholar 

  • Branstetter, S. 1986. Biological parameters of the sharks of the northwestern Gulf of Mexico in relation to their potential as a commercial fishery resource. Ph.D. Dissertation, Texas A&M University, College Station. 138 pp.

  • Branstetter, S. 1987a. Age and growth estimates for blacktip, Carcharhinus limbatus, and spinner, C. brevipinna, sharks from the northwestern Gulf of Mexico. Copeia (in press).

  • Bransteller, S. 1987b. Age and growth validation of the new born sharks held in laboratoriy aquaria, with comments on the life history of the Atlantic sharpnose shark, Rhizoprionodon terraenovae. Copeia (in press).

  • Branstetter, S. & J.D. McEachran. 1986. Age and growth of four carcharhinid sharks common to the Gulf of Mexico: a summary paper. pp. 361–371. In: T. Uyeno, R. Arai, T. Taniuchi & K. Matsuura (ed.) Indo-Pacific Fish Biology: Proceedings of the Second International Conference on Indo-Pacific Fishes, Ichthyol. Soc. Japan, Tokyo.

    Google Scholar 

  • Cadenat, J. & J. Blache. 1981. Requins de Meditterranee et d'Atlantique. Faune tropicale XXI ORSTOM, Paris. 330 pp.

    Google Scholar 

  • Cailliet, G.M., L.J. Natanson, B.A. Welden & D.A. Ebert. 1985. Preliminary studies on the age and growth of the white shark, Carcharodon carcharias, using vertebral bands. Southern Calif. Acad. Sci. Mem. 9: 49–60.

    Google Scholar 

  • Calliet, G.M., R.L. Radtke & B.A. Welden. 1986. Elasmobranch age determination and verification: a review. pp. 345–360. In: T. Uyeno, R. Arai, T. Taniuchi & K. Matsuura (ed.) Indo-Pacific Fish Biology: Proceedings of the Second International Conference on Indo-Pacific Fishes, Ichthyol. Soc. Japan, Tokyo.

    Google Scholar 

  • Casey, J.G., H.L. Pratt Jr. & C.E. Stillwell. 1985. Age and growth of the sandbar shark (Carcharhinus plumbeus) from the northwestern Atlantic. Can. J. Fish. Aquat. Sci. 42: 963–975.

    Google Scholar 

  • Clark, E. & K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15: 13–83.

    Google Scholar 

  • Clarke, T.A. 1971. The ecology of the scalloped hammerhead, Sphyrna lewini, in Hawaii. Pac. Sci. 25: 133–144.

    Google Scholar 

  • Compagno, L.J.V. 1984. FAO species catalogues. Vol. 4. Sharks of the world. An annotated and illustrated catalogue of the shark species known to date. Parts 1 & 2. FAO Fish. Synopsis (125) 4 (1&2). 655 pp.

  • Dodrill, J.W. 1977. A hook and line survey of the sharks found within five hundred meters of shore along Melbourne Beach, Brevard County, Florida, M.S. Thesis, Florida Institute of Technology, Melbourne. 304 pp.

  • Fabens, A.J. 1965. Properties and fitting of the von Bertalanffy growth curve. Growth 29: 265–289.

    CAS  Google Scholar 

  • Garrick, J.A.F., R.H. Backus & R.H. Gibbs, Jr. 1964. Carcharhinus floridanus, the silky shark, a synonym of C. falciformis. Copeia 1964: 369–375.

  • Gruber, S.H. & R.G. Stout. 1983. Biological materials for the study of age and growth in a tropical marine elasmobranch, the lemon shark, Negaprion brevirostris (Poey). NOAA Tech. Rep. NMFS 8: 193–205.

    Google Scholar 

  • Gulf of Mexico Fisheries Management Council. 1980. Draft environmental impact statement and fishery management plan for the shark and other elasmobranch fishery of the Gulf of Mexico: var. pag.

  • Holden, M.J. 1974. Problems in the rational exploitation of elasmobranch populations and same suggested solutions. pp. 117–137. In: F.R. Hardin-Jones (ed.) Sea Fisheries Research, John Wiley and Sons, New York.

    Google Scholar 

  • Holden, M.J. 1977. Elasmobranches. pp. 187–214. In: J.A. Gulland (ed) Fish Population Dynamics, John Wiley and Sons, New York.

    Google Scholar 

  • Klimley, A.P. 1981. Grouping behavior in the scalloped hammerhead. Oceanus 24: 65–71.

    Google Scholar 

  • Parsons, G.R. 1983. The reproductive biology of the Atlantic sharpnose shark, Rhizoprionodon terraenovae (Richardson). U.S. Fish. Bull. 81: 61–73.

    Google Scholar 

  • Pratt, H.L., Jr. 1980. Reproduction in the blue shark, Prionace glauca. U.S. Fish. Bull. 77: 445–470.

    Google Scholar 

  • Pratt, H.L., Jr. & J.G. Casey. 1983. Age and growth of the shortfin mako, Isurus oxyrinchus, using four methods. Can. J. Fish. Aquat. Sci. 40: 1944–1957.

    Google Scholar 

  • Radtke, R.L. & G.M. Cailliet. 1984. Age estimation and growth of the gray reef shark, Carcharhinus amblyrhynchos, from the northwestern Hawaiian Islands. Proceedings of the Second Symposium on Resource Investigations in the Northwestern Hawaiian Islands. UNI-SEAGRANT-MR-84-01: 121–127.

  • Sadowsky, V. 1965. The hammerhead sharks of the littoral zone of Sao Paulo, Brazil, with the description of a new species. Bull. Mar. Sci. 15: 1–12.

    Google Scholar 

  • Schwartz, F.J. 1983. Shark ageing methods and age estimation of scalloped hammerhead, Sphyrna lewini, and dusky, Carcharhinus obscurus, sharks based on vertebral ring counts. NOAA Tech. Rep. NMFS 8: 167–174.

    Google Scholar 

  • Smith, C.L. 1983. Summary of round table discussions on back calculation. NOAA Tech. Rep. NMFS 8: 45–47.

    Google Scholar 

  • Smith, S.E. 1984. Timing of vertebral hand deposition in tetracycline-injected leopard sharks. Trans. Amer. Fish. Soc. 113: 308–313.

    Article  Google Scholar 

  • Springer, S. 1960. Natural history of the sandbar shark, Eulamia milberti U.S. Fish. Bull. 61: 1–38.

    Google Scholar 

  • Springer, S. 1967. Social organization of shark populations. Chap. 9, pp. 149–174. In: P.W. Gilbert, R.F. Mathewson & D.P. Ralls (ed.) Sharks, Skates, and Rays, Johns Hopkins Press, Baltimore.

    Google Scholar 

  • Stevens, J.D. 1984a Life-history and ecology of sharks at Aldabra Atoll, Indian Ocean. Proc. Roy. Soc. London, B 222: 79–106.

    Article  Google Scholar 

  • Stevens J.D. 1984b. Biological observations on sharks caught by sport fishermen off New South Wales. Austr. J. Mar. Freshw. Res. 35: 573–590.

    Article  Google Scholar 

  • Strasburg, D.W. 1958. Distribution, abundance, and habits of pelagic sharks in the central Pacific Ocean. U.S. Fish. Bull. 58: 335–361.

    Google Scholar 

  • Thompson, K.S. & D.E. Simanek. 1977. Body form and locomotion in sharks. Amer. Zool. 17: 343–354.

    Google Scholar 

  • Thorson, T.L. & E.J. Lacy, Jr. 1982. Age, growth rate and longevity of Carcharhinus leucas estimated from tagging and vertebral rings. Copeia 1982: 110–116.

  • Wallett, T.S. 1973. Analysis of shark meshing returns off the Natal coast. M.S. Thesis, University of Natal, Durban. 117 pp.

  • Wathne, F. 1959. Summary report on exploratory long-line fishing for tuna in the Gulf of Mexico and Caribbean Sea, 1954–1957. Comm. Fish. Rev. 21. 26 pp.

  • Witzell, W.N. 1985. The incidental capture of sharks in the Atlantic United States Fishery Conservation Zone by the Japanese tuna longline fleet. NOAA Tech. Rep. NMFS 31: 21–22.

    Google Scholar 

  • Yoshimura, H & S. Kawasaki. 1985. Silky shark (Carcharhinus falciformis) in the tropical water of western Pacific. Reps. Japanese Group for Elasmobranch Studies 20: 6–10.

    Google Scholar 

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Branstetter, S. Age, growth and reproductive biology of the silky shark, Carcharhinus falciformis, and the scalloped hammerhead, Sphyrna lewini, from the northwestern Gulf of Mexico. Environ Biol Fish 19, 161–173 (1987). https://doi.org/10.1007/BF00005346

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Keywords

  • Chondrichthyes
  • Elasmobranchs
  • Fisheries
  • Ageing methods
  • Growth rates
  • Gestation periods
  • Maturity
  • Vertebral bands
  • Weight-length relationships
  • Life histories