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Biological aspects of silky shark Carcharhinus falciformis in the eastern Arabian Sea

Published online by Cambridge University Press:  21 October 2015

Sijo P. Varghese*
Affiliation:
Cochin Base of Fishery Survey of India, Kochangadi, Kochi, India
D.K. Gulati
Affiliation:
Cochin Base of Fishery Survey of India, Kochangadi, Kochi, India
N. Unnikrishnan
Affiliation:
Cochin Base of Fishery Survey of India, Kochangadi, Kochi, India
A.E. Ayoob
Affiliation:
Cochin Base of Fishery Survey of India, Kochangadi, Kochi, India
*
Correspondence should be addressed to:S.P. Varghese, Cochin Base of Fishery Survey of India, Kochangadi, Kochi, India email: varghesefsi@hotmail.com

Abstract

Reproduction, diet and growth of silky shark Carcharhinus falciformis in the eastern Arabian Sea are described based on 473 specimens collected from the gillnet-cum-longline landings at the Cochin fisheries harbour during 2012–2014. The reproductive biology of 215 males and 258 females was examined while 113 stomachs were sampled to study the diet. The von Bertalanffy growth parameters estimated using length-based models were asymptotic length (L ) = 309.80 cm, growth coefficient (K) = 0.10 year−1 and age at zero length (t 0) = −2.398 year. The sex ratio was significantly skewed to females. Seasonality in reproduction was not evident and in males, sexual maturity was attained at 201–223 cm total length (L T) with the size at maturity (L T50) occurring at 217.0 cm, whereas in females sexual maturity was attained at 224–231 cm L T and L T50 occurs at 226.5 cm. In total 114 embryos, in the length range of 12.2–65.1 cm were recovered from 15 pregnant females. Numbers of embryos in females were in the range of 3–13, averaging 7.6. Silky sharks of the eastern Arabian Sea feed primarily on swimming crab Charybdis smithii, with juveniles feeding principally on swimming crabs, while adults feed on actively swimming prey like squids and teleost fishes. This preliminary information on the reproduction, diet and growth should be useful to identify management strategies for silky sharks in the eastern Arabian Sea.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 2015 

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References

REFERENCES

Anderson, R.C. and Ahmed, H. (1993) Shark fisheries of the Maldives. Male: Ministry of Fisheries and Agriculture, Maldives and Rome: Food and Agriculture Organization of the United Nations.Google Scholar
Anderson, R.C. and Waheed, A. (1990) Exploratory fishing for large pelagic species in the Maldives. Madras: Bay of Bengal Programme.Google Scholar
Balasubramanian, C.P. and Suseelan, C. (2001) Distribution and population structure of deep-water crab Charybdis smithii (Decapoda: Portunidae) in the Arabian Sea and Bay of Bengal. Bulletin of Marine Science 68, 435449.Google Scholar
Bass, A.J., D'Aubrey, J.S. and Kistnasamy, N. (1973) Sharks of the East coast of Southern Africa. 1 – The genus Cacharhinus (Carcharhinidae). South African Association for Marine Biological Research, Oceanographic Research Institute, Investigational Report 33, 1168.Google Scholar
Blackburn, T.M., Gaston, K.J. and Loder, N. (1999) Geographic gradients in body size: a clarification of Bergmann's rule. Diversity and Distributions 5, 165174.CrossRefGoogle Scholar
Bonfil, R. (2008) The biology and ecology of the silky shark, Carcharhinus falciformis . In Camhi, M., Pikitch, E.K. and Babcock, E.A. (eds) Sharks of the open ocean: biology, fisheries and conservation. Oxford: Blackwell Science, pp. 114127.CrossRefGoogle Scholar
Bonfil, R., Amorim, A., Anderson, C., Arauz, R., Baum, J., Clarke, S.C., Graham, R.T., Gonzalez, M., Jolón, M., Kyne, P.M., Mancini, P., Márquez, F., Ruíz, C. and Smith, W. (2009) Carcharhinus falciformis. The IUCN Red List of Threatened Species. Version 2014.3. http://www.iucnredlist.org (last accessed 28 January 2015).Google Scholar
Bonfil, R., Mena, R. and de Anda, D. (1993) Biological parameters of commercially exploited silky sharks, Carcharhinus falciformis, from the Campeche Bank, Mexico. NOAA Technical Report NMFS 115, 7386.Google Scholar
Boopendranath, M.R. and Hameed, S. (2007) A profile of mechanized fishing activities based at Cochin fisheries harbor, Kerala, India. Fishery Technology 44, 129136.Google Scholar
Branstetter, S. (1987) Age, growth and reproductive biology of the silky shark, Carcharhinus falciformis, and the scalloped hammerhead, Sphyrna lewini, from the northwestern Gulf of Mexico. Environmental Biology of Fishes 19, 161173.Google Scholar
Cabrera-Chavez-Costa, A., Galván-Magaña, F. and Escobar-Sanchez, O. (2010) Food habits of the silky shark Carcharhinus falciformis (Muller and Henle, 1839) off the western coast of Baja California Sur, Mexico. Journal of Applied Ichthyology 26, 499503.Google Scholar
Castrejón, M. and Charles, A. (2013) Improving fisheries co-management through ecosystem-based spatial management: The Galapagos Marine Reserve. Marine Policy 38, 235245.Google Scholar
Castro, J.I. (1996) The sharks of North American Waters. College Station, TX: Texas A. and M. University Press.Google Scholar
Clarke, M. (1986) Handbook for the identification of cephalopod beaks. Oxford: Oxford University Press.Google Scholar
Colonello, J.H., Lucifora, L.O. and Massa, A.M. (2007) Reproduction of the angular angel shark (Squatina guggenheim): geographic differences, reproductive cycle, and sexual dimorphism. ICES Journal of Marine Science 64, 131140.Google Scholar
Compagno, L.J.V. (1984) FAO species catalogue, Volume 4, Part 2: Sharks of the World . An Annotated and Illustrated Catalogue of Shark Species Known to Date. Rome: Food and Agriculture Organization of the United Nations.Google Scholar
Compagno, L.J.V. and Niem, V.H. (1998) Carcharhinidae. Requiem sharks. In Carpenter, K.E. and Niem, V.H. (eds) FAO identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Rome: Food and Agriculture Organization of the United Nations, pp. 13121360.Google Scholar
Cortés, E. (1997) A critical review of methods of studying fish feeding based on analysis of stomach contents: application to Elasmobranch fishes. Canadian Journal of Fisheries and Aquatic Sciences 54, 726738.CrossRefGoogle Scholar
Duffy, L.M., Olson, R.J., Lennert-Cody, C.E., Galván-Magaña, F., Bocanegra-Castillo, N. and Kuhnert, P.M. (2015) Foraging ecology of silky sharks, Carcharhinus falciformis, captured by the tuna purse-seine fishery in the eastern Pacific Ocean. Marine Biology 162, 571593.Google Scholar
Fahmi, and Sumadhiharga, O.K. (2007) Size, sex and length at maturity of four common sharks caught from Western Indonesia. Marine Research in Indonesia 32, 719.Google Scholar
FAO (2006–2015) Fisheries and aquaculture software. FISAT II - FAO-ICLARM Stock Assessment Tool. In FAO Fisheries and Aquaculture Department [online]. Rome. Updated 28 November 2013. http://www.fao.org/fishery/topic/16072/en Google Scholar
Filmalter, J.D., Capello, M., Deneubourg, J., Cowley, P.D., and Dagorn, L. (2013) Looking behind the curtain: quantifying massive shark mortality in fish aggregating devices. Frontiers in Ecology and the Environment 11, 291296.Google Scholar
Fischer, W. and Bianchi, G. (eds) (1984) FAO species identification sheets for fishery purposes. Western Indian Ocean (Fishing Area 51). Rome: Food and Agriculture Organization of the United Nations.Google Scholar
Fourmanoir, P. (1961) Requins de la Côte Ouest de Madagascar. Memoires de l'Institut Scientifique de Madagascar Série F (Oceanographie) 4, 181.Google Scholar
Galván-Magaña, F., Nienhuis, H.J. and Klimley, A.P. (1989) Seasonal abundance and feeding habits of sharks of the lower Gulf of California, Mexico. California Fish and Game 75, 7484.Google Scholar
Galván-Tirado, C., Galván-Magaña, F. and Ochoa-Báez, R.I. (2015) Reproductive biology of the silky shark Carcharhinus falciformis in the southern Mexican Pacific. Journal of the Marine Biological Association of the United Kingdom 95, 561567.Google Scholar
Gerritsen, H.D. and McGrath, D. (2007) Precision estimates and suggested sample sizes for length frequency data. Fishery Bulletin 105, 116120.Google Scholar
Goode, G.B. and Bean, T.H. (1895) Oceanic ichthyology: a treatise on the deep-sea and pelagic fishes of world, with an atlas containing 417 figures – Indian Reprint. Delhi: Narendra Publishing House.Google Scholar
Hall, N.G., Bartron, C., White, W.T., Dharmadi and Potter, I.C. (2012) Biology of the silky shark Carcharhinus falciformis (Carcharhinidae) in the eastern Indian Ocean, including an approach to estimating age when timing of parturition is not well defined. Journal of Fish Biology 80, 13201341.CrossRefGoogle Scholar
Horn, H.S. (1966) Measures of ‘overlap’ in comparative ecological studies. American Naturalist 100, 419424.CrossRefGoogle Scholar
Hoyos-Padilla, M., Ceballos-Vezquez, B.P. and Galván-Magaña, F. (2012) Reproductive biology of the silky shark Carcharhinus falciformis (Chondrichthyes: Carcharhinidae) off the west coast of Baja California Sur, Mexico. Aqua, International Journal of Ichthyology 18, 1524.Google Scholar
IOTC (2014) Executive summary: silky shark. IOTC-2014-SC17-ES21[E].Google Scholar
Jackson, G., Norriss, J.V., Mackie, M.C. and Hall, N.G. (2010) Spatial variation in life history characteristics of snapper (Pagrus auratus) within Shark Bay, Western Australia. New Zealand Journal of Marine and Freshwater Research 44, 115.Google Scholar
John, M.E. (1995) Studies on yellowfin tuna, Thunnus albacares (Bonnaterre, 1788) in the Indian seas. PhD thesis. Bombay University, Bombay, India, 140157.Google Scholar
Joung, S., Chen, C., Lee, H. and Liu, K. (2008) Age, growth, and reproduction of silky sharks, Carcharhinus falciformis, in northeastern Taiwan waters. Fisheries Research 90, 7885.Google Scholar
Krebs, C.J. (1999) Ecological methodology. Menlo Park, CA: Benjamin Cummings.Google Scholar
Kubodera, T. (2005) Manual for identification of cephalopod beaks in the North West Pacific for researchers on feeding habits of marine mammals, sea birds and fishes. Version 1–1. Available online at http://www.kahaku.go.jp/research/db/zoology/Beak-E/key/key-1.htm Google Scholar
Longhurst, A.R. and Seibert, D.L. (1971) Breeding in an oceanic population of Pleuroncodes planipes (Crustacea, Galatheidae). Pacific Science 25, 426428.Google Scholar
Murua, H., Cohelo, R., Neves, M.N., Arrizabalaga, H., Yokawa, K., Romanov, E., Zhu, J.F., Kim, Z.G., Bach, P., Chavance, P., Delgado de Molina, A. and Ruiz, J. (2012) Preliminary Ecological Risk Assessment (ERA) for shark species caught in fisheries managed by the Indian Ocean Tuna Commission (IOTC). IOTC–2012–WPEB08–31 Rev_2. Mahé: Indian Ocean Tuna Commission.Google Scholar
Nesis, K.N. (1987) Cephalopods of the world. Neptune City: TFH Publications Inc.Google Scholar
Oshitani, S., Nakano, H. and Tanaka, S. (2003) Age and growth of the silky shark Carcharhinus falciformis from the Pacific Ocean. Fisheries Science 69, 456464.Google Scholar
Pauly, D. and David, N.C. (1981) ELEFAN I, a BASIC program for the objective extraction of growth parameters from length frequency data. Meeresforschung 28, 205211.Google Scholar
Pauly, D. and Munro, J.L. (1984) Once more on the comparison of growth in fish and invertebrates. ICLARM Fishbyte 2, 21.Google Scholar
Pinkas, L., Oliphant, M.S. and Iverson, L.R. (1971) Food habits of albacore, bluefin tuna, and bonito in California waters. Fish Bulletin 152, 1105.Google Scholar
Potier, M., Marsac, F. and Cherel, Y. (2007a) Forage fauna in the diet of three large pelagic fishes (lancetfish, swordfish and yellowfin tuna) in the western equatorial Indian Ocean. Fisheries Research 83, 6072.Google Scholar
Potier, M., Ménard, F. and Cherel, Y. (2007b) Role of pelagic crustaceans in the diet of the longnose lancetfish Alepisaurus ferox in the Seychelles waters. African Journal of Marine Science 29:113122.Google Scholar
Pratt, H.L. Jr. (1988) Elasmobranch gonad structure: a descriptive survey. Copeia 1988, 719729.Google Scholar
R Core Team (2013) R: A language and environment for statistical computing. Vienna: R Foundation for Statistical Computing. http://www.R-project.org/ Google Scholar
Rabehagasoa, N., Lorrain, A., Bach, P., Potier, M., Jaquemet, S., Richard, P. and Ménard, F. (2012) Isotopic niches of the blue shark Prionace glauca and the silky shark Carcharhinus falciformis in the southwestern Indian Ocean. Endangered Species Research 17, 8392.Google Scholar
Richards, F.J.A. (1959) A flexible growth functions for empirical use. Journal of Experimental Botany 10, 290300.CrossRefGoogle Scholar
Roff, D. (2002) Life history evolution. New York, NY: Sinauer Associates, 465 pp.Google Scholar
Romanov, E., Potier, M., Zamorov, V. and Ménard, F. (2009) The swimming crab Charybdis smithii: distribution, biology and trophic role in the pelagic ecosystem of the western Indian Ocean. Marine Biology 156, 10891107.CrossRefGoogle Scholar
Romanov, E. and Zamorov, V. (2007) Regional feeding patterns of the longnose lancetfish (Alepisaurus ferox Lowe, 1833) of the western Indian Ocean. Western Indian Ocean Journal of Marine Science 6, 3756.Google Scholar
Sánchez-de Ita, J.A., Quiñónez-Velázquez, C., Galván-Magaña, F., Bocanegra-Castillo, N. and Félix-Uraga, R. (2011) Age and growth of the silky shark Carcharhinus falciformis from the west coast of Baja California Sur, Mexico. Journal of Applied Ichthyology 27, 2024.Google Scholar
Silas, E.G., Sarvesan, R., Rao, K.S., Nair, K.P. and Meiyappan, M.M. (1985) Identity of common species of cephalopods of India. CMFRI Bulletin 37, 1337.Google Scholar
Smale, M.J., Watson, G. and Hecht, T. (1995) Otolith atlas of southern African marine fishes. Ichthyological Monographs No. 1. Grahamstown: J.L.B. Smith Institute of Ichthyology.Google Scholar
Smith, M.M. and Heemstra, P.C. (1986) Smith's sea fishes. Grahamstown: J.L.B. Smith Institute of Ichthyology.Google Scholar
Stehmann, M. (2002) Proposal of a maturity stages scale for oviparous and viviparous cartilaginous fishes (Pisces, Chondrichthyes). Archive of Fishery and Marine Research 50, 2348.Google Scholar
Stevens, J.D. (1984a) Biological observations on sharks caught by sport fisherman of New South Wales. Australian Journal of Marine and Freshwater Research 35, 573590.Google Scholar
Stevens, J.D. (1984b) Life-history and ecology of sharks at Aldabra Atoll, Indian Ocean. Proceedings of the Royal Society of London (Biological Sciences) 222, 79106.Google Scholar
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, 476494.Google Scholar
Strasburg, D.W. (1958) Distribution, abundance, and habits of pelagic sharks in the central Pacific Ocean. U.S. National Marine Fisheries Service Fishery Bulletin 58, 335361.Google Scholar
Varghese, S.P., Somvanshi, V.S. and Dalvi, R.S. (2014) Diet composition, feeding niche partitioning and trophic organisation of large pelagic predatory fishes in the eastern Arabian Sea. Hydrobiologia 736, 99114.Google Scholar
Varghese, S.P., Vijayakumaran, K. and Gulati, D.K. (2013) Pelagic megafauna bycatch in the tuna longline fisheries off India. IOTC-2013-WPEB09-36. Mahé: Indian Ocean Tuna Commission.Google Scholar
Zhu, G., Dai, X., Song, L.M. and Xu, L. (2011) Size at sexual maturity of bigeye tuna Thunnus obesus (Perciformes: Scombridae) in the tropical waters: a comparative analysis. Turkish Journal of Fisheries and Aquatic Sciences 11, 149156.Google Scholar