Roughtail Stingray: Bathytoshia centroura

Family: Dasyatidae
Common name(s)

Roughtail Stingray.

Identification

A very large, thick bodied stingray with a kite-shaped disc that is wider than long; disc width approximately 1.2-1.3 x length. Snout short and obtusely angular with a protruding tip. Anterior margins of disc mildly undulate or slightly convex. Pectoral fin apexes either narrowly rounded or angular. Pelvic fins relatively small with narrowly rounded apexes.
Eyes small. Snout length 1.5-2.5 x combined eye and spiracle length.
Mouth broad, usually containing 6 oral papillae. Weak labial furrows around mouth. Lower jaw weakly convex. Extremely broad, skirt shaped nasal curtain with a weakly fringed margin. Nostrils oval shaped. Juveniles lack dermal thorns but specimens exceeding 50cm DW have a row of stellate thorns and tubercles on midline of back and tail, and smaller thorns on snout and pectoral fins. Tail wide and depressed at base, tapering towards spines and then narrow until tip. 1-3 tail spines present. Tail beyond spines densely covered in thorns. Tail length when intact 1.6-1.8 x disc width. Ventral finfold long and low; base length approximately equal to distance between cloaca and tail spine. Ventral finfold height approximately half tail height.

Colour

Dorsum uniformly olive-brown or grey-brown, with a subtle row of small white pores on each pectoral fin that start close to mid points of the anterior pectoral fin margins, and run diagonally backwards, parallel to the pectoral fin posterior margins. Ventrum white. Ventral finfold usually dark.
Note: in the original description there is no mention of small white pores on pectoral fins but from personal observation, they are clearly present.

Size

Maximum disc width 220cm. Disc width at birth 34-37cm.

Habitat

Temperate and tropical seas. On soft substrates, sometimes adjacent to reefs. From shallow bays (including estuaries) to at least 275m. Usually shallower than 100m.

Distribution

Western North and South Atlantic but absent from much of the Caribbean and the northeast coast of South America. The roughtail stingray occurs from Cape Cod and the Georges Bank, southward along the eastern seaboard to the Bahamas and the Gulf of Mexico. Then from Rio Grande do Norte in Brazil to Golfo San Matías in Argentina.

Conservation Status

VULNERABLE

The Roughtail Stingray is captured in commercial and artisanal gillnets and trawls, and on recreational hook-and-line fisheries. In the United States, Roughtail Stingray may be caught as bycatch by recreational anglers where it is likely killed due to the danger of its spine. However, the level of mortality is likely low. Roughtail Stingray is caught as bycatch in artisanal shrimp trawl fisheries in southern Mexico but is generally discarded alive (J.C. Pérez-Jiménez unpubl. data 2019). It is also caught in the southeastern Gulf of Mexico in artisanal gillnets (Wakida-Kusunoki et al. 2018). Habitat loss due to tourism and coastal development is an issue in the Quintana Roo region of Mexico (M.P. Blanco-Parra pers. comm. 2019).Artisanal fisheries are intense across much of coastal Atlantic South America, and there are largely unmanaged commercial trawl and longline fisheries in many areas. In Eastern Brazil, artisanal fisheries are intense, gillnetting is the predominant artisanal gear, fishers there report that stocks are overexploited, and other elasmobranchs have been depleted (Guebert-Bartholo et al. 2011, Reis-Filho et al. 2016). This species is caught by shrimp trawlers off Sergipe State (Barreto et al. 2018). In southern Brazil, the trawl fishery began in the 1960s and entered a period of rapid expansion in the 1990s and 2000s, resulting in over 650 vessels fishing at depths of 20–1,000 m (Port et al. 2016). Artisanal fisheries there are also intense, and 58% of stocks targeted by artisanal fishers are overexploited, half of those being collapsed (Vasconcellos et al. 2011). In Uruguay, the industrial trawl fleet was developed in the late 1970s, and many stocks were overexploited by the 1990s (Defeo et al. 2011). In Argentina, trawl fisheries started to expand in the 1950s and increased rapidly in the mid-1980s (Watson et al. 2006). Gillnets are prevalent there and target elasmobranchs (Chiaramonte 1998, Colautti et al. 2010).

Citation

Carlson, J., Charvet, P., Avalos, C., Briones Bell-lloch, A., Cardenosa, D., Espinoza, E., Herman, K., Morales-Saldaña, J.M., Naranjo-Elizondo, B., Pacoureau, N., Pilar Blasco, M., Pérez Jiménez, J.C., Schneider, E.V.C., Simpson, N.J. & Talwar, B.S. 2020. Bathytoshia centrouraThe IUCN Red List of Threatened Species 2020: e.T104065040A3122808. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T104065040A3122808.en. Downloaded on 05 February 2021.

Reproduction

Matrotrophic aplacental viviparity. Litter size 2-6.

Diet

Diet consists mainly of bony fishes, crabs, bivalves, gastropods, and cephalopods.

Behavior

Rests on the substrate for long periods each day. Excavates large depressions in the sand when hunting for benthic invertebrates.

Reaction to divers

Shy but approachable with non-aggressive movements. Generally bolts when approached closely.

Diving logistics

Roughtail stingrays are occasionally seen by divers and beachgoers in the US.
I saw one next to the wreck of the Carib Sea while diving with sandtiger sharks on the Outer Banks of North Carolina.
In the summer months, roughtail stingrays sightings have also been reported from Zach’s Beach in Marthas Vinyard, swimming just off the beach in 2m of water (Tim Costikyan pers. com.).
There are also reports from various locations around Florida although some of these are likely large southern stingrays.

Similar species

Southern Stingray Distinguished by short rows of thorns on shoulders and a lack of thorns on tail.