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(Sphyrna Zygaena) in Saint Peter and Saint Paul Archipelago: Range Extension for the Equatorial Region

(Sphyrna Zygaena) in Saint Peter and Saint Paul Archipelago: Range Extension for the Equatorial Region

Lat. Am. J. Aquat. Res., 45(2): 481-484, 2017 First record of zygaena in equatorial Atlantic 481 DOI: 10.3856/vol45-issue2-fulltext-22

Short Communication

First record of the smooth hammerhead (Sphyrna zygaena) in Saint Peter and Saint Paul Archipelago: range extension for the equatorial region

1 1 1 2 3 Natalia Bezerra , Bruno C.L. Macena , Sibele A. Mendonça , Ramón Bonfil & Fábio H.V. Hazin 1Department of Oceanography, Postgraduate Program in Oceanography Federal University of Pernambuco, Recife, 2Océanos Vivientes A.C., Mexico City, Mexico 3Department of Fisheries and Aquaculture, Federal Rural University of Pernambuco, Recife, Brazil Corresponding author: Natalia Bezerra ([email protected])

ABSTRACT. A smooth (Sphyrna zygaena) was found in Saint Peter and Saint Paul Archipelago in May 2015. This is the first confirmed occurrence of a smooth hammerhead shark in an equatorial oceanic island and suggests a geographic range extension for the . Keywords: Sphyrna zygaena, Sphyrnidae, new occurrence, oceanic island, equatorial Atlantic.

From all eight known shark orders, 2011). Despite the general view that the area of presents the highest species diversity, including the occurrence for the species is limited to high latitudes, a smooth hammerhead shark (Sphyrna zygaena smooth hammerhead shark (Fig. 1) was captured in the (Linnaeus, 1758)), which belongs to the Sphyrnidae Saint Peter and Saint Paul Archipelago (SPSPA) (Fig. family. Currently, the genus Sphyrna is composed by 2), a Brazilian group of oceanic equatorial islands. The nine species, with six of them occurring in Brazilian SPSPA (0°55’02”N, 029°20’42”W) is formed by a waters: Sphyrna media, Sphyrna mokarran, Sphyrna group of small islands between the South American and tiburo, Sphyrna tudes, Sphyrna lewini, S. zygaena African continents and southern and northern (Compagno, 1984), as well as the new species Sphyrna hemispheres, located about 1,100 km from the coast of gilberti (Pinhal et al., 2012). Brazil and 1,700 km from the coast of Guinea-Bissau, The species comprising this genus are mainly . distinguished due to the presence or absence of not ches A female S. zygaena was captured in 15 May 2015, in the cephalic region, as well as other morphological during shark fishing operations for telemetry studies. aspects such as the size and position of fins, for The shark was caught in the eastern part of the example (Compagno et al., 2005; Vooren et al., 2005; archipelago on a drum line composed of 16 circle hooks Navia & Mejía-Falla, 2011). Among the species of size 16, using flying fish (Cheilopogon cyanopterus) as Sphyrna commonly captured in Brazil, S. zygaena, S. bait. Unfortunately the shark did not survive the capture mokarran and S. lewini are the largest and the ones that procedure. The smooth hammerhead shark was easily show a higher degree of morphological similarity. identified by the following key diagnostic features: These three species are cosmopolitan, inhabit oceanic head arched with four notches and without a median and coastal regions of tropical, subtropical and indentation; first moderately high, with temperate seas, and are present along the entire coast of second dorsal and pelvic fins low; pelvic fins not Brazil, with the exception of S. zygaena which is falcate; and lower caudal fin lobe without a dark blotch distributed mainly in latitudes greater than 20ºS on it. The shark was eviscerated and measured right (Casper et al., 2005; Compagno et al., 2005). after it was landed, presenting the following measure- In the southeast and south regions of Brazil, the ments: 226 cm total length (퐿T), 173 cm fork length, smooth hammerhead shark is caught near the coast 157 cm precaudal length and 57 cm interdorsal space. using trawls and gill nets, and offshore in pelagic The total and eviscerated weights were 49.2 kg and 46.1 longline fisheries (Vooren et al., 2005; Amorim et al., kg, respectively. The gonadal macroscopic analysis

______Corresponding editor: Andrés Abitia 482 Latin American Journal of Aquatic Research

Figure 1. a) Female of smooth hammerhead shark caught in Saint Peter and Saint Paul archipelago, b) ventral, c) dorsal head view. ( Four notches).

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Figure 2. New occurrence location of the smooth hammerhead shark: Saint Peter and Saint Paul Archipelago (SPSPA). a) Capture area (■) in SPSPA, and b) SPSPA location. showed the female smooth hammerhead shark was beaks. Cephalopods are commonly an important diet developing by Stehmann (2002) maturity scale, item for this species (Rogers et al., 2012; Galván- although Vooren et al. (2005), in the southern region of Magaña et al., 2013; Bornatowski et al., 2014). The Brazil, have registered adult females with shorter specimen is kept in the biological collection of the lengths (between 198 cm and 210 cm 퐿T) than the one Oceanography Fisheries Laboratory of the Federal described in this study. Rural University of Pernambuco, Brazil. S. zyganea is The degree of stomach repletion was 25% with the the second hammerhead shark species to be reported for presence of unidentified cephalopod tissues and some the SPSPA, however, the occurrence of the other First record of Sphyrna zygaena in equatorial Atlantic 483

species, S. lewini, in the archipelago is considered Eastern Tropical Pacific. Environ. Biol. Fish., 91: 165- common (Lubbock & Edwards, 1981; Vaske Jr. et al., 176. 2005). Bezerra et al. (2016) reported significant catches Bezerra, N.P.A., P. Travassos & F.H.V. Hazin. 2016. of hammerhead around the archipelago, yet, it Vulnerability to longline fishery of three hammerhead was not possible to identify the different species in sharks species in the Southwestern and Equatorial order to confirm the presence of S. zygaena in the area. . J. Fish. Biol., 89: 1419-1433. A possible occurrence of a smooth hammerhead shark Bornatowski, H., R.R. Braga, V. Abilhoa & M.F.M. near the equatorial region was listed by Soto (2001), in Corrêa. 2014. Feeding ecology and trophic compa- the Fernando de Noronha Archipelago. Nonetheless, risons of six shark species in a coastal ecosystem off according to the author, the record requires confir- Southern Brazil. J. Fish. Biol., 85: 246-263. mation. Smooth hammerhead sharks may seek shelter Casper, B.M., A. Domingo, N. Gaibor, M.R. Heupel, E. and food in island ecosystems, such as scalloped Kotas, A.F. Lamónaca, J.C. Pérez-Jimenez, C. hammerhead sharks, which usually form aggregations Simpfendorfer, W.D. Smith, J.D. Stevens, A. Soldo & in these environments (Hearn et al., 2010; Bessudo et C.M. Vooren. 2005. Sphyrna zygaena. The IUCN Red al., 2011; Ketchum et al., 2014). List of Threatened Species 2005: e.T39388A1019 3797. [www.iucnredlist.org/details/39388/0]. Revie- In almost 20 years of intense monitoring around the wed: 14 August 2016. SPSPA, however, the smooth hammerhead shark had never been reported. The species of the genus Sphyrna Compagno, L.J.V. 1984. Sharks of the world: an annotated are usually identified in logbooks only and illustrated catalogue of shark species known to as "hammerhead", which hinders the understanding of date. Part 2. Carcharhiniformes. FAO species their geographic distribution, abundance, and impor- catalogue. FAO Fish. Synopsis, 125, 4(2): 251-655. tance in fisheries catches, thus contributing to a higher Compagno, L.J.V., M. Dando & S. Fowler. 2005. Sharks risk for these species (Gallagher et al., 2014). This of the world. Princeton University Press, New Jersey, study confirms the presence of the smooth hammerhead 368 pp. shark in the Atlantic equatorial zone, indicating a Gallagher, A.J., N. Hammerschlag, D.S. Shiffman & S.T. possible range extension for the species. Delimiting the Giery. 2014. Evolved for extinction: the cost and occurrence area of the species is extremely important to conservation implications of specialization in ham- decide effective management and conservation merhead sharks. Bio Sci., 64: 619-624. measures for smooth hammerhead sharks, which are Galván-Magaña, F., C. Polo-Silva, S.B. Hernández- classified as vulnerable in the IUCN (International Aguilar, A. Sandoval-Londoño, M.R. Ochoa-Díaz, N. Union for the Conservation of Nature) Red List of Aguilar-Castro, D. Castañeda-Suárez, A. Chavez- Threatened Species (Casper et al., 2005). Costa, A. Baigorrí-Santacruz, E. Torres-Rojas & L.A. Abitia-Cárdenas. 2013. Shark on cephalo- ACKNOWLEDGMENTS pods in the Mexican and Ecuadorian Pacific Ocean. Deep-Sea Res. II, 95: 52-62. We are grateful to Conselho Nacional de Desenvol- Hearn, A., J. Ketchum, A. Klimley, E. Espinoza & C. vimento Científico e Tecnológico (CNPq) for granting Peñaherrera. 2010. Hotspots within hotspots? the fellows (NPAB, BCLM, SAM) and to the Hammerhead shark movements around Wolf Island, PRÓARQUIPÉLAGO/SECIRM program (Secretaria Galapagos Marine Reserve. Mar. Biol., 157: 1899- da Comissão Interministerial para os Recursos do Mar) 1915. for the logistical support. Thanks to fishermen that Ketchum, J.T., A. Hearn, A.P. Klimley, C. Peñaherrera, E. contributed to this study. Espinoza, S. Bessudo, G. Soler & R. Arauz. 2014. Inter-island movements of REFERENCES sharks (Sphyrna lewini) and seasonal connectivity in a marine protected area of the eastern tropical Pacific. Amorim, C.A., N. Della-Fina & N. Piva-Silva. 2011. Mar. Biol., 161: 939-951. Hammerheads sharks, Sphyrna lewini and S. zygaena Lubbock, R. & A.J. Edwards. 1981. The fishes of Saint caught by longliners off Southern Brazil, 2007-2008. Paul’s Rocks. J. Fish. Biol., 18: 135-157. Collect. Vol. Sci. Pap. ICCAT, 66: 2121-2133. Navia, A.F. & P.A. Mejía-Falla. 2011. Guía para la Bessudo, S., G.A. Soler, A.P. Klimley, J.T. Ketchum, A. identificación de especies de tiburones y rayas Hearn & R. Arauz. 2011. Residency of the scalloped comercializadas en el Pacífico colombiano. Fundación hammerhead shark, Sphyrna lewini at Malpelo Island SQUALUS, Conservación Internacional, Colombia, and evidence of migration to other islands in the 36 pp. 484 Latin American Journal of Aquatic Research

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Received: 29 September 2016; Accepted: 28 November 2016

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