Feeding habits of Bigeye Houndshark, Iago omanensis (Elasmobranchii; Triakidae); a typical deep water shark from the Gulf of Oman

Ali Reza Rastgoo, Eelia Etemadi-Deylami, Mohammad Reza Mirzaei


In this study, the feeding habits of Bigeye Houndshark, Iago omanensis, a typical deep water shark, were examined in the Gulf of Oman by analyzing of stomach contents. In addition, the effects of sex and seasons (spring and summer) on its feeding habits were evaluated. Bigeye Houndshark diet consists of mostly teleost fishes, and to a lower extent on crustaneans, molluscs and sea snakes. The great importance of teleost in the diet of Bigeye Houndshark may be due to the fact that teleosts are the dominant in terms of biomass and abundance in the area where Bigeye Houndshark exist, allowing them to exploit food resources available in the environment. No significant differences were found between sexes and seasons. This species occupy high trophic position within the food webs. These results present new data that will allow us to understand the role of Bigeye Houndshark in the deep water of Gulf of Oman to effect of fishing activity on its population dynamics in the future.


Shark, Foraging ecology, Diet, Ecological role.

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Baremore I.E., Murie D.J., Carlson J.K. (2008). Prey selection by the Atlantic angel shark Squatina dumeril in the northeastern Gulf of Mexico. Bulletin of Marine Science, 82: 297-313.

Baremore I.E., Murie D.J., Carlson J.K. (2010). Seasonal and size-related differences in diet of the Atlantic angel shark Squatina dumeril in the northeastern Gulf of Mexico. Aquatic Biology, 8: 125-136.

Barnes A., Sutaria D., Harry A.V., Jabado R.W. (2018). Demographics and length and weight relationships of commercially important sharks along the north‐western coast of India. Aquatic Conservation: Marine and Freshwater Ecosystems, 1-10.

Bornatowski H., Wosnick N., Do Carmo W.P.D., Corrêa M.F.M., Abilhoa V. (2014). Feeding comparisons of four batoids (Elasmobranchii) in coastal waters of southern Brazil. Journal of the Marine Biological Association of the United Kingdom, 1-9.

Brodziak J., Link J. (2002). Ecosystem-based fishery management: what is it and how can we do it? Bulletin of Marine Science, 70: 589-611.

Browman H.I., Stergiou K.I. (2004). Marine Protected Areas as a central element of ecosystem-based management: defining their location, size and number. Marine Ecology Progress Series, 274: 269-303.

Colwell R.K. (2005). EstimateS: statistical estimation of species richness and shared species from samples. Version 7.5. User's guide and application, http://purl. oclc. org/estimates.

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: 726-738.

Cortés E. (1999). Standardized diet compositions and trophic levels of sharks. ICES Journal of Marine Science, 56: 707-717.

Davies N.B., Krebs J.R., West S.A. (2012). An introduction to behavioural ecology. John Wiley & Sons. 520 p.

Eagderi S., Fricke R., Esmaeili H.R., Jalili P. (2019). Annotated checklist of the fishes of the Persian Gulf: Diversity and conservation status. Iranian Journal of Ichthyology, 6(Suppl. 1): 1-171.

Ebert D.A., Bizzarro J.J. (2007). Standardized diet compositions and trophic levels of skates (Chondrichthyes: Rajiformes: Rajoidei). Environmental Biology of Fishes, 80: 221-237.

Ellis J.R., Pawson M.G., Shackley S.E. (1996). The comparative feeding ecology of six species of shark and four species of ray (Elasmobranchii) in the North-East Atlantic. Journal of the Marine Biological Association of the United Kingdom, 78: 89-106.

Espinoza M., Munroe S.E.M., Clarke T.M., Fisk A.T., Wehrtmann I.S. (2015). Feeding ecology of common demersal elasmobranch species in the Pacific coast of Costa Rica inferred from stable isotope and stomach content analyses. Journal of Experimental Marine Biology and Ecology, 470: 12-25.

Froese R., Pauly D. (2000). Fishbase 2000, Concepts, design and data sources,. ICLARM, Los Banos, Laguna, Philippines. 344 p.

Hambright K.D. (1994). Morphological constraints in the piscivore‐planktivore interaction: implications for the trophic cascade hypothesis. Limnology and Oceanography, 39: 897-912.

Henderson A., McIlwain J., Al-Oufi H., Al-Sheile S., Al-Abri N. (2009). Size distributions and sex ratios of sharks caught by Oman's artisanal fishery. African Journal of Marine Science, 31: 233-239.

Hussey N.E., Dudley S.F., McCarthy I.D., Cliff G., Fisk A.T. (2011). Stable isotope profiles of large marine predators: viable indicators of trophic position, diet, and movement in sharks? Canadian Journal of Fisheries and Aquatic Sciences, 68: 2029-2045.

Hyslop E.J. (1980). Stomach contents analysis-a review of methods and their application. Journal of Fish Biology, 17: 411-429.

Jabado R.W., Al Ghais S.M., Hamza W., Henderson A.C., Al Mesafri A.A. (2015). Diet of two commercially important shark species in the United Arab Emirates: milk shark, Rhizoprionodon acutus (Rüppell, 1837), and slit‐eye shark, Loxodon macrorhinus (Müller & Henle, 1839). Journal of Applied Ichthyology, 31: 1-6.

Jabado R.W., Kyne P.M., Pollom R.A., Ebert D.A., Simpfendorfer C.A., Ralph G.M., Dulvy N.K. (2017). The conservation status of sharks, rays, and chimaeras in the Arabian Sea and adjacent waters. Environment Agency – Abu Dhabi, UAE and IUCN Species Survival Commission Shark Specialist Group, Vancouver, Canada.

Juanes F., Buckel J.A., Scharf F.S. (2001). Predatory behaviour and selectivity of a primary piscivore: comparison of fish and non-fish prey. Marine Ecology Progress Series, 217: 157-165.

Kamura S., Hashimoto H. (2004). The food habits of four species of triakid sharks, Triakis scyllium, Hemitriakis japanica, Mustelus griseus and Mustelus manazo, in the central Seto Inland Sea, Japan. Fisheries science, 70: 1019-1035.

Ludwig J.A., Reynolds J.F. (1988). Statistical ecology: a primer in methods and computing. John Wiley & Sons.

Magurran A.E. (2013). Measuring biological diversity. John Wiley & Sons. 264 p.

Nair R.V., Appukkuttan K.K. (1973). Observation on the food of deep sea sharks Halaelvrus hispidus (Alcock), Eridacnis radcliffei smith and Iago omanensis Compagno and Springer. Indian Journal of Fisheries, 20: 575-583.

Navarro J., Coll M., Preminger M., Palomera I. (2013). Feeding ecology and trophic position of a Mediterranean endemic ray: consistency between sexes, maturity stages and seasons. Environmental Biology of Fishes, 96: 1315-1328.

Navia A.F., Mejía-Falla P.A., Giraldo A. (2007). Feeding ecology of elasmobranch fishes in coastal waters of the Colombian Eastern Tropical Pacific. BMC Ecology, 7: 8: 1-10.

O’Shea O.R., Thums M., van Keulen M., Kempster R.M., Meekan M.G. (2013). Dietary partitioning by five sympatric species of stingray (Dasyatidae) on coral reefs. Journal of Fish Biology, 82: 1805-1820.

Pauly D., Froese R., Sa-a P., Palomares M.L., Christensen V., Rius J. (2000). TrophLab in MS Access. (Downloaded: May 30, 2010, www.fishbase.org/ download/TrophLab2K.zip).

Pinkas L., Oliphant M., Iverson I. (1971). Food habits of albacore, bluefin tuna and bonito in Californian waters. California Department of Fish and Game: Fish Bulletin, 152: 1-105.

Rastgoo A., Fatemi S., Valinassab T., Mortazavi M. (2018a). Feeding habits and trophic level of Himantura gerrardi (Elasmobranchii; Dasyatidae) in northern Oman Sea: effects of sex and size class. Iranian Journal of Fisheries Sciences, 17: 137-150.

Rastgoo A.R., Navarro J. (2017). Trophic levels of teleost and elasmobranch species in the Persian Gulf and Oman Sea. Journal of Applied Ichthyology, 33: 403-408.

Rastgoo A.R., Navarro J., Valinassab T. (2018b). Comparative diets of sympatric batoid elasmobranchs in the Gulf of Oman. Aquatic Biology, 27: 35-41.

Reynolds R.M. (1993). Physical oceanography of the Gulf, Strait of Hormuz, and the Gulf of Oman: results from the Mitchell Expedition. Marine Pollution Bulletin, 27: 35-60.

Routley M.H., Nilsson G.E., Renshaw G.M. (2002). Exposure to hypoxia primes the respiratory and metabolic responses of the epaulette shark to progressive hypoxia. Comparative Biochemistry and Physiology Part A: Molecular and Integrative Physiology, 131: 313-321.

Scenna L., García De La Rosa S., Díaz de Astarloa J. (2006). Trophic ecology of the Patagonian skate, Bathyraja macloviana, on the Argentine continental shelf. ICES Journal of Marine Science, 63: 867-874.

Schils T., Wilson S.C. (2006). Temperature threshold as a biogeographic barrier in northern Indian Ocean macroalgae. Journal of Phycology, 42: 749-756.

Simpfendorfer C.A., Goodreid A.B., McAuley R.B. (2001). Size, sex and geographic variation in the diet of the tiger shark, Galeocerdo cuvier, from Western Australian waters. Environmental Biology of Fishes, 61: 37-46.

Valinassab T., Daryanabard R., Dehghani R., Pierce G.J. (2006). Abundance of demersal fish resources in the Persian Gulf and Oman Sea. Journal of the Marine Biological Association of the United Kingdom, 86: 1455-1462.

Valls M., Olivar M.P., de Puelles M.F., Molí B., Bernal A., Sweeting C. (2014). Trophic structure of mesopelagic fishes in the western Mediterranean based on stable isotopes of carbon and nitrogen. Journal of Marine Systems, 138: 160-170.

Waller G.N.H., Baranes A. (1994). Food of Iago omanensis, a deep water shark from the northern Red Sea. Journal of Fish Biology, 45: 37-45.

Wetherbee B.M., Cortés E. (2004). Food consumption and feeding habits. In: J.C. Carrier, J.A. Musick, M.R. Heithaus (eds). The Biology of Sharks and Their Relatives. CRC Press, Florida. Boca Raton, FL. pp: 224-246.

Yick J., Tracey S., White R. (2011). Niche overlap and trophic resource partitioning of two sympatric batoids co‐inhabiting an estuarine system in southeast Australia. Journal of Applied Ichthyology, 27: 1272-1277.


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