D1: moderate, round front edge; origin ~ opposite pectoral rear tip
low ridge Ds
D2 > 2.3% TL
top teeth serrated, broad, triangular, semi-oblique
pectoral: large, curved
Carcharhinus obscurus (Lesueur, 1818)
Body moderately slender to moderately stout; snout moderately short, broad, rounded, length 1-1.4 in distance between nostrils; nasal flaps rudimentary; upper front teeth broadly triangular, straight to a little oblique, serrated; lower front teeth with low, narrow, serrated points; low ridge on back between dorsal fins; origin of first dorsal fin over or slightly behind free rear corner of pectoral fins; first dorsal fin relatively low (height 6-9.1% of TL), front edge broadly arched, tip pointed to narrowly rounded; origin of second dorsal above anal fin origin, with long free rear tip; pectoral long, curved, pointed tip.
Very similar in appearance and easily confused with C. galapagensis; best means of separation is the lower dorsal fin: 5.8-9.9 % of TL in C. obscurus vs 9.1-12.1% of TL in C. galapagensis.
Grey, shading to white ventrally, with a faint, near-horizontal, grey band invading the white of upper abdomen; tips of fins dusky.
Size: reaches 420 cm; size at birth 69-100 cm.
Habitat: Inshore to offshore coastal- pelagic, primarily on continental shelves, not in low salinity habitats.
Depth: 0-400 m.
Circumglobal in tropical and warm temperate seas; from California to the Gulf of California and central Mexico, and the Revillagigedos.