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DESCRIPTION
Body robust, slightly
compressed. Head with upper jaw and snout prolonged in a stout bill,
round in cross-section. Nape elevated. Branchiostegal membranes
joined but free from isthmus. No gillrakers. Small, file-like teeth
in jaws and palatines. First dorsal fin height less than body depth,
pointed anteriorly and decreasing gradually, ending close to the
second dorsal fin. Two anal fins, both pointed anteriorly; origin of
second slightly behind that of second dorsal fin origin. Pectoral
fin rigid (cannot be folded flat against body side). Pelvic fin very
narrow, depressible into ventral grooves. Two keels on each side of
caudal peduncle and located at the base of the caudal fin
lobes.
color :
head and
body dark blue dorsally and silvery-white ventrally. First dorsal
fin dark blue or blackish; other fin dark brown.
size : common
150-310 cm (max. 460 cm - ca. 700 kg).
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DISTINGUISHING CHARACTERISTICS
The upper jaw is modified into a long bill
which is circular in cross section. This upper jaw is approximately
twice the length of the lower jaw.
Two
dorsal and anal fins are present. The first dorsal fin is large,
much taller than the width of the body. This large fin runs most of
the length of the body, with the longest ray being the 20th.
The
first anal fin is set far back on the body. Second dorsal and anal
fins approximately mirror one another in size and shape. Both are
short and concave.
The
pectoral and pelvic fins are long with the pelvic fins almost twice
as long and nearly reaching the origin of the first anal fin. The
pelvic fins have one spine and multiple soft rays fused together.
A
pair of grooves run along the ventral side of the body, into which
the pelvic fins can be depressed.
The caudal peduncle has double keels and caudal notchs on the
upper and lower surfaces. The lateral line is readily visible.
BIOLOGY / ECOLOGY
Feeding on a variety of fish, including small
tuna, squids and crustaceans.
habitat :
epipelagic oceanic.
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