FAO Species Identification Guide for Fishery Purposes Western

1216 Sharks
11a. Diagonal distance from centre of snout tip to inner edge of nostril greater than distance
from nostril to upper labial furrow (Fig. 12a) . . . . . . . . . . . . . . . . . . . . . . . . . . . → 12
11b. Diagonal distance from centre of snout tip to inner edge of nostril less than or about
equal to distance from nostril to upper labial furrow (Fig. 12b) . . . . . . . . . . . . . . . . . → 14
12a. Snout acutely pointed; eye closer to first gill opening than snout tip (Fig. 13) . . . Squalus japonicus
12b. Snout narrowly parabolic; eye slightly closer to snout tip than first gill opening . . . . . . . . . → 13
a) b)
Fig. 12 ventral view of head
13a. Head relatively narrow, direct preorbital distance longer than interorbital distance;
monospondylous vertebrae 38 to 42 or more (Fig. 14) . . . . . . . . . . . . . . . . . Squalus sp. F
13b. Head relatively broad, direct preorbital distance shorter than interorbital distance;
monospondylous vertebrae 43 to 46 (Fig. 15) . . . . . . . . . . . . . . . . . . . Squalus mitsukurii
14a. First dorsal fin raked backwards
slightly (Fig. 16a); denticles lanceolate
(Fig. 17a); precaudal vertebrae
78 to 82 (Fig. 18) . . . . . . . . Squalus megalops
14b. First dorsal fin more upright (Fig.16b);
denticles with 3 posterior cusps
(Figs 17b, c); more than 82 precaudal
vertebrae . . . . . . . . . . . . . . . . . . → 15
Fig. 13 Squalus japonicus
Fig. 14 Squalus sp. F Fig. 15 Squalus mitsukurii
a) b)
Fig. 16 first dorsal fin
a) b) lateral keels c)
Fig. 17 Fig. 18 Squalus megalops