Common names
Cazón del Golfo, Gulf smoothhound

Short Description
Diagnosis after Heemstra, 1997 [1103]: Caudal fin with prominent, narrowly-rounded ventral lobe, the lobe angle 79°-106° (11 specimens measured). Trailing edges of dorsal fins not frayed. Rear (distal) edge of pectoral and pelvic fins distinctly concave. Head moderate, pre-pectoral distance 17-23% TL; interorbital distance 3.9-4.6% TL; pre-oral snout length 5.4-6.3% TL; inter-nostril distance 2.6-3.3% TL; orbit diameter 2.3-3.1 % TL. Upper-jaw labial folds long (1.9-2.5% TL), distinctly longer than lower-lip folds. Teeth (Fig. 17A) noticeably asymmetric, higher crowned than in most Mustelus, the primary cusp rounded, with a small accessory cusp on posterolateral margin of crown; tooth counts 58-69/60-62. Midlateral flank denticles (Figs. 16b, 17B) distinctly tridentate, strongly sculptured with 3-6 prominent ridges extending to rear margin of scale. Buccopharyngeal cavity (Figs. 18C, 22) almost devoid of denticles; patch of denticles at anterior end of palate not extending posterior to upper lip fold; lingual patch confined to tip of tongue; posterior margin of fifth epibranchial pharyngeal pads with evenly-spaced, denticle-covered, shallow notches (Fig. 22). Palatoquadrate a single cartilage on each side of jaw. Intestine with seven turns in spiral valve. Diagnostic vertebral numbers are given in Figures 23-25. Head and body of adults immaculate grey or greyish-tan dorsally; juveniles usually with sooty smudges on apices of dorsal fins and sometimes on tip of caudal fin.

Distribution
Western Central Atlantic: apparently endemic to the Gulf of Mexico, from off Panama City, Florida to the Bay of Campeche. Source: www.gbif.org

Biology
Ovoviviparous, embryos feed solely on yolk [733]. Distinct pairing with embrace [17086].

Size / Weight / Age
83.0 cm TL (male/unsexed; [1103]); 140 cm TL (female)

Habitat
pelagic-oceanic; marine; depth range 20 - 250 m [13336], usually 42 - 91 m [13336]

Remarks
shark-references Species-ID=3822;