Pastinachus sephen ( Fabricius, 1775 )

Bogorodsky, Sergey V., Zajonz, Uwe, Saeed, Fouad N. & Weigmann, Simon, 2021, Notes on batoid fishes of the Socotra Archipelago (north-western Indian Ocean) with four new records, Zootaxa 4951 (3), pp. 511-528 : 523-524

Pastinachus sephen ( Fabricius, 1775)

Fantail stingray, Cowtail ray

Fig. 10

oaja sephen Fabricius in Niebuhr (ex Forsskål), 1775: 17; no types known; type locality: Jeddah , Saudi Arabia and Al-Luhayya, Yemen, Red Sea.

Material examined: No specimen collected, underwater photograph, Socotra Island, Ras Bidou, 14 m depth, 18 April 2019 .

Distinctive characters: masṫẚnachus sephen is characterised by having a broadly rhomboidal disc, its width 1.2–1.3 times its length; eyes small, length of orbit and spiracle 1.6–1.8 in snout length; 2 or 3 large, pale, seedshaped tubercles mid-centrally on disc (merging with denticle band in adults); pelvic fins large, tips narrowly rounded; tail length usually less than twice disc width, with base broad and depressed; tail with a very deep cutaneous ventral fold, no dorsal fold, tip of tail usually free of fold and tapering continuously to terminal filament; usually one caudal sting well back on tail (Psomadakis eṫ al. 2015; Last eṫ al. 2016c).

Colouraṫẚon: Dorsal disc uniform yellowish-brown, greyish or greyish brown, orbit and spiracle blackish, membranous ventral tail fold and posterior tail dark grey to black. Ventral surface white, often with narrow black margins (Psomadakis eṫ al. 2015; Last eṫ al. 2016c).

Distribution: The exact species distribution is unknown, positive records in the wider Arabian region include the Red Sea from its type locality ( Golani & Bogorodsky 2010), Gulf of Tadjoura (Lips eṫ al. 2016), Oman (Randall 1995), the Gulf (Almojil eṫ al. 2015) and Pakistan (Psomadakis eṫ al. 2015). It has also been reported from the western coast of India (Bineesh eṫ al. 2016).

Remarks: Photographed individuals match well all characters of masṫẚnachus sephen as given by Last eṫ al. (2016c), particularly referring to the presence of prominent tubercles on dorsal middisc. The species occurs on sand and mud bottom of estuaries, bays and sheltered lagoons, at depths of 0–60 m ( Weigmann 2016), often resting nearly buried in the sand or mud. The present confirmed record from the Socotra Archipelago is based on individuals observed on silty sand bottom close to large rocks with overhangs in Ras Bidou, western part of Socotra Island, at a depth of 14 m. masṫẚnachus sephen is included as near threatened in IUCN Red List Assessments and urgently requires conservation management (Kyne eṫ al. 2017). masṫẚnachus aṫer ( Macleay, 1883), reported from the Gulf, Oman and Madagascar eastward to New Caledonia, is a very similar species, which might possibly be found off Socotra Archipelago as well. It may be confused with mK sephen but differs by the length of eye and spiracle 1.7–2.3 in snout length (versus 1.6–1.8 in mK sephen) and the presence of 3–4 tubercles mid-centrally on disc that are barely visible relative to the surrounding denticles (versus 2–3 tubercles prominent mid-centrally on disc in mK sephen).

Figures

FIGURE 10. masṫẚnachus sephen, underwater photograph, Ras Bidou, Socotra Island, 14 m depth. Photo by S.V. Bogorodsky.