First record of the ragged-tooth shark, Odontaspis ferox (Risso, 1810), in the Venezuelan Caribbean
One specimen of the ragged-tooth shark, Odontaspis ferox, was caught by a commercial shark fishery to the north of Cape Codera (10° 56′ N, 66° 02′ W), northeastern Venezuela. The specimen (sex unidentified, ~ 180 cm TL, ~ 30 kg) was identified on the basis of its dry jaw and characteristic dentition: which comprise teeth moderately large, with prominent narrow cusps and two or three pairs of lateral cusplets. This is the first record of O. ferox in the Venezuelan Caribbean, and this finding complements the knowledge of geographic distribution of this rare species in the Western Central Atlantic.
KeywordsDistribution Elasmobranch Species Taxonomy
The dramatic decline in the abundance of sharks, together with a greater understanding of their ecological importance and the high vulnerability of some of these species to extinction have attracted increasing scientific concern in recent years (Baum and Myers 2004; Ferretti et al. 2010; Dulvy et al. 2014; Heupel et al. 2014). Sharks and rays are among the marine organisms under direct threat from overfishing either as bycatch or in direct fisheries (Jackson et al. 2001; Baum and Myers 2004; Clarke et al. 2007). Knowledge about biodiversity and species distribution is crucial for the development of management and conservation plans, in order to contribute to the recovery and sustainability of shark populations. In the case of rare species, their occurrence may be under-reported, which can have management implications since many shark species are conservation-dependent (Santander-Neto et al. 2011).
The ragged-tooth shark, Odontaspis ferox, is an uncommon and poorly known species, widely distributed in warm-temperate and tropical seas of continental and insular shelves and upper slopes (Compagno 2001; Fergusson et al. 2008). It is a bulky shark with a long and conical snout and mouth very long and angular; five medium to large gill slits, all anterior to the pectoral fin; two dorsal fins, the first dorsal large and situated closer to the pectoral fins, and the second dorsal fin slightly smaller than the first dorsal fin. The dentition of this species is very characteristic, with teeth moderately large, prominent narrow cusps and two or three pairs of lateral cusplets; and body colour is typically brownish-grey dorsally and lighter below with darker dusky spots along the sides (Compagno 2001). Odontaspis ferox is a large shark with a maximum total length around 400 cm TL in both sexes, and a size at birth of about 100 cm TL (Fergusson et al. 2008).
In the Western Atlantic, its distribution was unknown until the 1990s. The first reports of O. ferox for the Western Atlantic were from Yucatán, Gulf of Mexico (Bonfil 1995), Natal, northeastern Brazil (Menni et al. 1995), and North Carolina, US Atlantic (Sheehan 1998). More recently, this species has been recorded from off South Carolina and Florida, US Atlantic (Ross and Quattrini 2007), Fernando de Noronha Archipelago and Ceará, northeastern Brazil (Garla and Garcia 2008; Santander-Neto et al. 2011), and Barranquilla, Colombian Caribbean (Anguila et al. 2016). Despite the recent increase in reports of O. ferox in the region has not hitherto been reported for the Venezuelan Caribbean (between Colombia and Brazil). Currently, this species is listed as vulnerable in the IUCN Red List of Threatened Species due to its rarity, very low fecundity and high vulnerability to exploitation (Graham et al. 2016).
The fishing boat involved in the capture of the shark comes from the medium-scale artisanal fishing fleet based on Margarita Island, and this particular boat (13 m in length, equipped with a central motor of 120 hp) operates with bottom gillnets (300–600 m long, 3.0 m deep, 21.0 cm square mesh) in an extensive area of the northeastern region of Venezuela, from around Margarita Island to Cape Codera and La Tortuga Island. According to the information provided by fishermen, the captured specimen (sex unidentified) measured ~ 180 cm total length and weighed ~ 30 kg. The body colour reported for the specimen was uniformly grey without the apparent presence of dark spots on the back or sides.
This capture of O. ferox near Cape Codera is the first report of the occurrence of this species in the Venezuelan Caribbean and complements knowledge of its range in the Western Central Atlantic. Although this species appears to have a cosmopolitan distribution in the Atlantic, records of its occurrence have been very limited in the tropical region. The paucity of capture records of O. ferox may be attributable to the low relative abundance of this species (Graham et al. 2016) but also to its deep-water habitat out of the depth range of most commercial and traditional fishing operations (Sheehan 1998). Available data indicated that the overall depth range for O. ferox is 10–883 m; however, most specimens have been registered at depths between 200 and 600 m (Fergusson et al. 2008), reflecting the preference of this species for zones of deep waters generally close to the seabed around islands and outer continental shelves.
According to the maturity size reported for O. ferox (males: 200–250 cm TL; females: 300–350 cm TL; Fergusson et al. 2008), the specimen captured (180 cm TL) in the Venezuelan Caribbean corresponds to an immature individual. The absence of captures of pregnant females with advanced stages of gestation and newborn individuals has prevented the identification of the nursery grounds of this species through its range of distribution. Fergusson et al. (2008) suggested that nurseries of O. ferox are commonly associated with deep offshore habitats on upper continental and insular slopes. The Caribbean Sea comprises a combination of environments (including chain islands, reef systems, submarine basins, and underwater seamounts) that provide a wide variety of habitats for sharks. The capture of a large number of pregnant females and juveniles of oceanic sharks in the Venezuelan Caribbean showed that this tropical region is crucial in the life cycle of this group of fishes (Tavares and Arocha, 2008).
The monitoring of fishing activities is essential to obtain biological information and to increase knowledge of the exploited species. The Venezuelan governmental organizations with responsibility in fishery administration and data collection must make an effort to improve and expand the programs that monitor fishing. These actions, together with the support of researchers, will ensure more accurate information on the fishing operations and the species captured. Additionally, the use of novel techniques (BRUVs, baited remote underwater video systems) helps to improve our understanding of distributions, ecology and behaviour of marine fauna (Wellington et al. 2016), for example in cases of poorly known and vulnerable species such as the ragged-tooth shark.
The authors thank the fishermen R. Hernandez and A. Hernandez who donated the jaw of O. ferox to the Centro para la Investigación de Tiburones (CIT) of Venezuela. We are also grateful to H. Ramirez for the photographic images used in this study and A.G. Gutiérrez for his assistance with digital processing of images. Finally, we especially thank Dr. A. Grant and anonymous referees for your helpful comments and suggestions to improve the manuscript.
RT organized the co-authors, wrote the manuscript, and prepared the final maps and images. LS measured the teeth, analyzed data, and gave technical assistance in photographic sessions. JMB received the shark jaw from fishermen and interviewed the captain of the fishing boat. All authors read and approved the final manuscript.
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The authors declare that they have no competing interests.
- Anguila R, Nieto-Alvarado LE, Hernández-Beracasa L. Nuevos registros de peces de esqueleto cartilaginoso para el Caribe colombiano y uno como ampliación de su distribución geográfica en el Caribe colombiano para Bocas de Ceniza, departamento de Atlántico, Colombia. Bol Invest Mar Cost. 2016;45(2):361–73.Google Scholar
- Bonfil R. Is the ragged-tooth shark cosmopolitan? First record from the western North Atlantic. J Fish Biol. 1995. https://doi.org/10.1111/j.1095-8649.1995.tb01902.x.CrossRefGoogle Scholar
- Castellanos P, Varela R, Muller-Karger F. Descripción de las áreas de surgencia al sur del Mar Caribe examinadas con el sensor infrarrojo AVHRR. Mem Fund La Salle Cienc Nat. 2002;154:55–76.Google Scholar
- Compagno LJV. Sharks of the world: an annotated and illustrated catalogue of shark species known to date. FAO Species Catalogue for Fishery Purposes: Rome; 2(1) 2001.Google Scholar
- Dulvy NK, Fowler SL, Musick JA, Cavanagh RD, Kyne PM, Harrison LR, Carlson JK, Davidson LN, Fordham SV, Francis MP, Pollock CM, Simpfendorfer CA, Burgess GH, Carpenter KE, Compagno LJV, Ebert DA, Gibson C, Heupel MR, Livingstone SR, Sanciangco JC, Stevens JD, Valenti S, White WT. Extinction risk and conservation of the world’s sharks and rays. eLife. 2014. https://doi.org/10.7554/eLife.00590.001.
- Ferretti F, Worm G, Britten GL, Heithaus MR, Lotze HK. Patterns and ecosystem consequences of shark declines in the ocean. Ecol Lett. 2010. https://doi.org/10.1111/j.1461-0248.2010.01489.x.
- Garla RC, Garcia J. Occurrence of the ragged-tooth shark, Odontaspis ferox, at Fernando de Noronha archipelago, western equatorial Atlantic. Mar Biodivers Rec. 2008. https://doi.org/10.1017/S1755267206003952.
- Graham KJ, Pollard DA, Gordon I, Williams S, Flaherty AA, Fergusson I, Dicken M. Odontaspis ferox. In: The IUCN Red List of Threatened Species, vol. 2016; 2016. https://doi.org/10.2305/IUCN.UK.2016-1.RLTS.T41876A2957320.en. Accessed 20 June 2019.CrossRefGoogle Scholar
- Jackson JBC, Kirby MX, Berger WH, Bjorndal KA, Botsford LW, Bourque BJ, Bradbury RH, Cooke R, Erlandson J, Estes JA, Hughes TP, Kidwell S, Lange CB, Lenihan HS, Pandolfi JM, Peterson CH, Steneck RS, Tegner MJ, Warner TR. Historical overfishing and the recent collapse of coastal ecosystems. Science. 2001. https://doi.org/10.1126/science.1059199.CrossRefGoogle Scholar
- McConnell MC, Thunell RC, Lorenzoni L, Astor Y, Wright JD, Fairbanks R. Seasonal variability in the salinity and oxygen isotopic composition of seawater from the Cariaco Basin, Venezuela: Implications for paleosalinity reconstructions: Geochem, Geophys, Geosyst; 2009. https://doi.org/10.1029/2008GC002035.CrossRefGoogle Scholar
- Menni RC, Hazin FHV, Lessa RPT. Occurrence of the ragged-tooth shark, Odontaspis ferox, in the western equatorial Atlantic. Chondros. 1995;5:3–4.Google Scholar
- Muller-Karger F, Varela R. Influjo del Río Orinoco en el Mar Caribe: Observaciones con el CZCS desde el espacio. Mem Soc Cienc Nat La Salle. 1990;50:361–90.Google Scholar
- Santander-Neto J, Faria VV, Castro ALF, Burgess GH. New record of the rare ragged-tooth shark, Odontaspis ferox (Chondrichthyes: Odontaspidae) from the south-West Atlantic identified using DNA bar coding. Mar Biodivers Rec. 2011. https://doi.org/10.1017/S1755267211000698.
- Tavares R, Arocha F. Species diversity, relative abundance and length structure of oceanic sharks caught by the Venezuelan longline fishery in the Caribbean Sea and western-Central Atlantic. Zootec Trop. 2008;26(4):489–503.Google Scholar
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