Istiophoridae
by I. Nakamura
Large pelagic fishes of the oceans (some to about 4 m TL), with rounded and elegantly streamlined bodies, characterized by elongation of the snout (pre-maxillae) to form a cylindrical spear. Mouth large, teeth in adults fin-like; gill membranes joined to each other entirely and free from isthmus; no gillrakers. 2 dorsal fins, the first beginning far forward, just behind head, the second small; anal fin separate in two parts; pelvic fins with soft rays and spine fused; 2 horizontal keels on each side of caudal peduncle, caudal fin strongly forked.
Epipelagic in warmer oceanic waters (usually above thermocline), generally moving to cooler areas during hot season for feeding and returning to lower latitudes to spawn. Feeding on pelagic fishes, crustaceans and squids. Of some commericial value in Clofnam area, but more important elsewhere (Japan, etc.).
Genera 3; in Clofnam area 3.
Recent revisions: Nakamura, Iwai and Matsubara (1968), Nakamura (1974, 1985).