Mustelus norrisi

Springer, 1939

Narrowfin smooth-hound
Classification: Elasmobranchii Carcharhiniformes Triakidae

Reference of the original description
Springer, S. (1939)
Two new Atlantic species of dog sharks, with a key to the species of Mustelus. Proceedings of the United States National Museum, 86(3058), 461–468

Image of the original description
Image in copyright.

Mustelus norrisi
Holotype: USNM: 106639; Paratype: Bass Biol. Lab.: 321 (whereabouts unknown) Bass Biol. Lab.: 319 (whereabouts unknown) Bass Biol. Lab.: 320 (whereabouts unknown) Bass Biol. Lab.: 317 (whereabouts unknown) BMNH: 1939.5.5.1 MCZ: 35222 (ex 318) UMMZ: 117094 USNM: 57369; USNM: 104333; USNM: 317610;

Description :

Citation: Mustelus norrisi Springer, 1939: In: Database of modern sharks, rays and chimaeras,, World Wide Web electronic publication, Version 07/2024

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Mustelus norrisi Springer, 1939, adult, male, 950 mm TL, caught at Central Brazilian coast © Otto Bismarck Fazzano Gadig, Laboratório de Pesquisa de Elasmobrânquios, UNESP, Brazil
Common names
spa Boca Dulce, spa Cazón, spa Cazón perro, spa Cazón viuda, spa Musola viuda, spa Viuda, spa Viuda virma, fra \(T\) Emissole veuve, eng Florida Smooth-hound, eng Florida smooth hound, eng Florida smoothhound, eng Narrowfin smooth hound, eng Narrowfin smooth-hound, por Cação

Short Description
Original daiagonis after Springer [3013]: A small species (males mature at 600 mm or less in contrast to those of M. canis, which become mature at 750 mm or more). Form slender, tail long, back little elevated. Head relatively narrow, flattened above; snout rounded, of moderate length. A middorsal ridge in the skin extending from before the first dorsal between the fins to the caudal. Fins relatively small; pectorals narrow; lower lobe of the caudal well developed and acute in full-grown specimens; origin of the first dorsal behind the inner angle of the pectoral. Eyes large, with diamond-shaped pupils; distance between nostrils less than horizontal diameter of the orbit. Mouth small, greatly arched, not broadly rounded anteriorly, the lines of occlusion of the jaws forming an angle of 90° or less at the apex; outer labial fold either longer or shorter than the inner, of variable length. Teeth paved but with elevated blunt crowns, higher than in most species of Mustelus; with several series in function, teeth of upper and lower jaws similar, vestigial accessory cusps present on occasional teeth but most of these single; a few teeth, tricuspid in outline, in most specimens examined. Dermal denticles of adults similar in structure over the flat surfaces of the skin of the body, typical denticles regular in outline, 4-ridged, with the two central ridges reaching or nearly reaching the posterior apex, denticles usually longer than broad (one of average size, 0.21 by 0.35 mm), 6-ridged denticles rare even along the middorsal line. Color uniform, without lighter or darker spots; Light gray. Measurements of the types are given in table 1.

Western Atlantic: Florida, USA and the northern Gulf of Mexico to Venezuela; also southern Brazil. Source:

Human uses
fisheries: minor commercial; price category: medium; price reliability: questionable: based on ex-vessel price for species in this genus

Viviparous (with a yolk-sac placenta) [517]. Distinct pairing with embrace [17086]. Found on the continental shelves, on muddy or sandy bottoms to about 80 m depth. Feeds on crabs and shrimps, and also bony fishes.

Size / Weight / Age
110 cm TL (male/unsexed; (Ref. 40637)); max. published weight: 13.8 kg (Ref. 40637)

demersal; marine; depth range ? - 100 m [13336], usually 3 - 4 m (Ref. 55311)

shark-references Species-ID=3815;

Parasites (arranged by Jürgen Pollerspöck)
  • Calicotyle asterii (Szidat, 1970) Timofeeva, 1985 [17436]
  • Calicotyle stossichi Braun, 1899 [17436]

  • Acanthobothrium schalli Vardo-Zalik & Campbell, 2011 [13116] [28741]

  • Pandarus sinuatus Say, 1818 [16589]
  • Perissopus dentatus Steenstrup & Lütken, 1861 [16589]