FAO Species Identification Guide for Fishery Purposes Western

1214 Sharks
Squatinidae: trunk much flattened dorsoventrally; eyes on
upper side of head; anterior margins of pectoral fins extending
forward past gill openings and partly concealing
them; pelvic fins also very broad, wing-like.
All other shark families: anal fin present.
Key to the species of Squalidae occurring in the area
1a. Second dorsal fin, and usually first dorsal
fin (except in Squaliolus), without a
spine . . . . . . . . . . . . . . . . . . . . . . . → 2
1b. Spines present on both dorsal fins . . . . . . . → 7
2a. Lips fringed (Fig. 1a); edges of lower teeth serrated (Fig. 2a) . . . . . . . . . . . . . Dalatias licha
2b. Lips not fringed; edges of lower teeth smooth . . . . . . . . . . . . . . . . . . . . . . . . . . . → 3
a) ventral view of head
b) fringed lips
Fig. 1 Dalatias licha
ventral view
Squatinidae
c) lateral view
dorsal view
3a. Cusps of lower teeth erect, distal edges not notched (Fig. 2b); lips expanded and
suctorial; rear end of first dorsal-fin base about over pelvic-fin origins (Fig. 3) . . Isistius brasiliensis
3b. Cusps of lower teeth oblique, distal edges notched (Fig. 2c); lips not expanded and
suctorial; rear end of first dorsal-fin base well in front of pelvic-fin origins . . . . . . . . . . . . → 4
serrated
smooth
not
notched
a) Dalatias licha b) Isistius
brasiliensis
Fig. 2 lower tooth
notched
c) Euprotomicrus
bispinatus
1 st dorsal fin
Fig. 3 Isistius brasiliensis
pelvic fin
4a. Second dorsal-fin base as long as first dorsal-fin base; upper caudal-fin lobe not
shortened, caudal fin not paddle-shaped (Fig. 4); giant benthic sharks, adults to over
4 m total length and possibly born at a size over 35 cm . . . . . . . . . . . . . Somniosus pacificus
(occurrence in the area uncertain)
4b. Second dorsal-fin base at least twice as long as first dorsal-fin base; upper caudal-fin
lobe shortened, caudal fin paddle-shaped (Fig. 5); dwarf oceanic sharks, adults not
exceeding 15 to 27 cm total length . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . → 5
Fig. 4 Somniosus pacificus Fig. 5