Atropus armatus


Longfin trevally NGR
Characteristic features:
Colour:

Blue-grey above, silvery-white below; blackish blotch on upper edge of opercle. Spinous dorsal fin blackish; second dorsal and anal fins pale with leading edge dusky to blackish; caudal fin grey with leading and trailing edges blackish; pelvic fins black in specimens <10 cm FL.

Size:

Up to 58 cm TL.

Distribution:

Indo-West Pacific in tropical waters.

Habitat:

Coastal rocky and coral reefs, from the surface to 60 m depth. Juveniles may occur in estuaries.

Biology:

Likely feeds on small fishes. Found in solitary but also forms small groups and is frequently found swimming along reef edges. Length at maturity is estimated at 21–22 cm FL1.

Indonesian fisheries:

Caught mainly by hook-and-line.

Similar species:

Platycaranx chrysophrys
Longnose trevally

Carangoides chrysophrys

Platycaranx chrysophrys differs in having a head profile slightly steep (vs. very steep in adults); lobe of second dorsal fin usually shorter than head length (vs. longer); no filaments on soft dorsal and anal-fin rays (vs. mature males over 21 cm FL only with filaments) and gill rakers (including rudiments) on first gill arch 21–26 (vs. 31–37).

Turrum coeruleopinnatus
Coastal trevally

Carangoides coeruleopinnatus

Turrum coeruleopinnatus differs in having a second dorsal-fin lobe short, less than head length in adults (vs. long, greater than head length); gill rakers (including rudiments) on first gill arch 21–27 (vs. 31–37).

Carangichthys dinema
Shadow trevally

Carangoides dinema

Carangichthys dinema differs in having a head profile gently sloped (vs. steep); brown blotches between bases of second dorsal-fin rays (vs. no markings) and a scaleless breast area separated from scaleless pectoral-fin base by a broad band of scales (vs. scaleless breast area uninterrupted to scaleless pectoral-fin base).

Atropus hedlandensis
Bumpnose trevally

Carangoides hedlandensis

Atropus hedlandensis differs in having a steep head profile with a bump level with eyes, becoming more pronounced with age (vs. no bump) and gill rakers (including rudiments) on first gill arch 20–27 (vs. 31–37).

Platycaranx malabaricus
Malabar trevally

Carangoides malabaricus

Platycaranx malabaricus differs in having the second dorsal-fin lobe short, less than head length (vs. long, greater than head length); second dorsal-fin central rays never filamentous (vs. filamentous in males >21 cm FL); scaleless breast area long ventrally, extending to second anal-fin origin (vs. short, extending to pectoral-fin base) and scaleless breast area large, covering area above and in front of pectoral-fin base (vs. scaleless breast area small extending to pectoral-fin base only).

Carangichthys oblongus
Coachwhip trevally

Carangoides oblongus

Carangichthys oblongus differs in having the straight part of lateral line slightly longer than curved part (vs. straight part slightly shorter); scaleless breast area separated from scaleless pectoral-fin base by a broad band of scales (vs. scaleless breast area uninterrupted to scaleless pectoral-fin base).

Platycaranx talamparoides
Imposter trevally

Carangoides talamparoides

Platycaranx talamparoides differs in having the second dorsal-fin lobe short, less than head length (vs. long, greater than head length); head profile sloped (vs. very steep) and gill rakers (including rudiments) on first gill arch 27–31 (vs. 31–37).

External links:
References:
  1. Carpenter, K, Niem, V. Species identification guide for fisheries purposes. The living marine resources of the western central Pacific. Bony fishes part 2 (Mugilidae to Carangidae). Rome: FAO; 1999;4.