Gallery 4.1: Bony Fish Identification

An observer will encounter many fish species during the course of their duties. This gallery will review some of the more common fish and point out their identifying characteristics. (Photo: Fukofuka & Itano, 2007)

Spotted Oceanic Triggerfish (TRI): white spots (red arrows), one or more spines above the head (yellow arrows), body turns solid black when brine frozen (bottom left photo). (Photo: Fukofuka & Itano, 2007)

Mackerel Scad (MSD): Skinny shape, metallic black upper body and silver/white lower body, with a black mark on the upper gill flap (arrows) (Photo: Fukofuka & Itano, 2007)

Bigeye Trevally (CXS): Distinct shape with blue/green upper body and silver/white lower body, large eyes, white-tipped dorsal and ventral fins (arrows), yellowish-black caudal fin (Photo: Fukofuka & Itano, 2007)

Greater Amberjack (AMB): Green/gray upper body and silver/white lower body, faint stripe along middle side (red arrow), dark strip over the eye (in the young especially, blue arrow) (Photo: J.E. Randall)

Blue Sea Chub (KYC): Allover dot pattern, dusky fins, elongated dorsal and anal fins (blue arrows). Very common, particularly under FADs and logs (Photo: Fukofuka & Itano, 2007)

Great Barracuda (GBA): Long, thin fish with short, dark bars on silver sides (blue arrows), irregular dark sport on underside (red arrows), lower jaw sticks out (Photo: Fukofuka & Itano, 2007)

Longfin Batfish (BAO): distinctive shape with black bars (blue arrows) and yellow pelvic fins (yellow arrows) (Photo: Fukofuka & Itano, 2007)

Kawakawa (KAW): The body shape is similar to tuna, however there are characteristic black spots on the belly, close to the pelvic fin (blue arrow), and broken diagonal stripes on its back (red arrow) (Photo: Fukofuka & Itano, 2007)

Bullet Tuna (BLT): Similar to the frigate tuna, except that the pectoral fin does NOT reach past the start of the scaleless area (Photo: Fukofuka & Itano, 2007)

Blue Marlin (BUM): First dorsal fin height is ½ to ¾ of body depth, pectoral fins are nearly straight (not curved), blue-black color on upper half of body with white/silver below, second dorsal fin slightly behind the second anal fin (red bar) (Photo: Fukofuka & Itano, 2007)

1, 2, 3, 6 = Spotted Oceanic Triggerfish (TRI)
4, 5 = Rainbow Runner (RRU) 
7 = Great Barracuda (GBA) 
(Photo: Fukofuka & Itano, 2007)

From top: BLT, FRI, KAW, YFT, BET, SKJ. (Photo: Fukofuka & Itano, 2007)

Parts of a fish (Photo: Fukofuka & Itano, 2007)

Rainbow Runner (RRU): Long, thin fish with blue and yellow stripes along the body. (Photo: Fukofuka & Itano, 2007)

Bigeye Scad (BIS): Long metallic blue-green body, large eyes, black spot on gill flap (arrow) (Photo: Fukofuka & Itano, 2007)

Golden Trevally (GLT): Yellow/silvery body, yellow fins, pattern of broad and narrow black bars (blue arrows), black spots on sides in adults (red arrow) (Photo: J.E. Randall)

Cottonmouth Jack (USE): Dark gray body with lighter vertical bars (red arrows), dark fins, and the tongue and inside of mouth are pure white (blue arrow) (Photo: NOAA Fisheries)

Dolphin Fish/Mahi Mahi (DOL): Distinct body shape, blue-green upper body, yellow lower body, males have a high forehead (red arrow) (Photo: Fukofuka & Itano, 2007)

Tripletail (LOB): Dark brown or black upper body with a bronze/gray lower body, small eyes near mouth, extended round dorsal and anal fins (yellow arrows) (Photo: Fukofuka & Itano, 2007)

Wahoo (WAH): A long body shape with vertical bars across most of the body (blue arrows) (Photo: Fukofuka & Itano, 2007)

Frigate Tuna (FRI): Scaleless area on the dorsal posterior (top rear) area (red arrow), short pectoral fin that reaches just past the start of the scaleless area (blue bars and arrows) (Photo: J.E. Randall)

Ocean Sunfish (MOX) and Sharptail Sunfish (MRW). (Photo: Fukofuka & Itano, 2007)

Black Marlin (BLM): First dorsal fin height is ½ or less body depth, pectoral fins are curved and stick out from the body, blue-black color on upper half of body with white/silver below, second dorsal fin slightly in front the second anal fin (red bar) (Photo: Fukofuka & Itano, 2007)

From top: spotted oceanic triggerfish (TRI), mackerel scad (MSD) and blue sea chub (KYC) (Photo: Fukofuka & Itano, 2007)

All frozen specimens: 
Mackerel scads (yellow arrow) 
Oceanic triggerfish (blue arrow) 
Rainbow runner (red arrow) 
(Photo: Fukofuka & Itano, 2007)

Mackerel scads (yellow arrow) 
Oceanic triggerfish (blue arrow) 
Rainbow runner (red arrow) 
(Photo: Fukofuka & Itano, 2007)