Bythaelurus tenuicephalus


Classification: Elasmobranchii Carcharhiniformes Pentanchidae

Reference of the original description
Bythaelurus tenuicephalus n. sp., a new deep-water catshark (Carcharhiniformes, Scyliorhinidae) from the western Indian Ocean. Zootaxa, 4013 (1): 120–138

Bythaelurus tenuicephalus
Holotype: ZMH: 10163; Paratype: ZMH: 26070;

Description :

Citation: Bythaelurus tenuicephalus KASCHNER, WEIGMANN & THIEL, 2015: In: Database of modern sharks, rays and chimaeras,, World Wide Web electronic publication, Version 07/2020

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Bythaelurus tenuicephalus KASCHNER, WEIGMANN & THIEL, 2015 paratype, ZMH 26070, juvenile male, 285 mm TL © Dr. Simon Weigmann, Center of Natural History, Hamburg, Germany
Common names
eng Narrowhead Catshark

Short Description
Original Diagnosis after KASCHNER, WEIGMANN & THIEL, 2015 [22987]: A very small scyliorhinid species with the following characteristics: body firm and elongated; snout long (preorbital length 6.7–7.1% TL) and slender, only slightly bell-shaped in dorsoventral view without distinct lateral indention; pre-outer nostril length 1.2 times internarial space; preorbital snout length 1.0–1.4 times interorbital space; preoral snout length 1.3–1.4 times in mouth width; eye length 14.0–15.3 times in predorsal distance, 6.0–7.0 times in head length and 1.7–1.8 times eye height; head length 2.7–3.1 times width at level of maximum outer extent of anterior nostrils; head width at level of maximum outer extent of anterior nostrils only 1.2 times width at level of lateral indention of head, equal to preorbital length, and 7.2–7.3% TL; tongue and roof of mouth loosely set with oral papillae of distinct size; pelvic anterior margin 1.9–2.1 times in pectoral fin anterior margin; first dorsal fin base 1.9 times in interdorsal space; length of second dorsal fin inner margin 1.4 times in second dorsal fin height; second dorsal-fin base length 5.9–6.9% TL; anal-fin base 0.9–1.1 times interdorsal space. Coloration in preservative: bicolored with an abrupt lateral demarcation of medium brown dorsal and whitish ventral color, about five indistinct darker blotches on dorsolateral surface at gill slits and dorsal and caudal fins; fins lighter towards their margins; monospondylous trunk vertebrae centra 38–40, diplospondylous precaudal centra 43–50, total centra about 133–138.

Known from the upper slope off northern Tanzania in the Pemba Channel between Zanzibar and Pemba Island, 5° 27.9’ S, 39° 18.8’ E, and from off southern Mozambique, 21°12'8" S, 35°41'8" E–21°16'6" S, 35°41'3" E [22987]

Size / Weight / Age
TL 291 mm [22987]

marine; depth range 463-550 m [22987]

upper jaw with 67–76 and lower jaw with 62–64 rows of small tricuspidate teeth [22987]

shark-references Species-ID=14435;