The giant trevally (Caranx ignobilis) is a species of large marine fish classified in the jack family, Carangidae.
Short description - Dorsal spines (total): 9; Dorsal soft rays (total): 18-21; Anal spines: 3; Anal soft rays: 15 - 17; Vertebrae: 24. This species is distinguished by the following characters: gill rakers (including rudiments) 5-7 + 15-17 = 20-24; breast naked ventrally, typically with a small to large patch of prepelvic scales; colour in life of adults, head and body silvery grey to black above, usually paler below; fins usually uniformly grey to black, fish from turbid coastal waters often with yellow fins, the anal fin usually brightest
Giant trevally habitat
This speciesis pelagic and occur to depths exceeding 100 m (Wetherbee et al. 2004). This species occurs in many habitats, including rock, coral reef channels, inner reefs, and seaward reefs (Lieske and Myers 1994, Mundy 2005). This speciesis also found over sand flats inshore. This species is a facultative schooling species (Major 1978) with adults solitary or in schools. Juveniles occur in small schools over sandy inshore bottoms (Myers 1999) and occasionally in turbid estuaries (Blaber and Cyrus1983). Wide tolerance of salinity has been observed in juveniles and subadults (Blaber and Cyrus1983). However, the presence of estuarine habitat isn't necessary for this speciesto thrive, as observed by Sudekum et al. (1991) in the NW islands of Hawaii where this speciesoccurs in high abundance, but estuarine habitat is absent. This speciesfeeds during the day, mostly on demersal and pelagic fishes. This speciesalso consumes cephalopods and crustaceans (Blaber and Cyprus1983, Sudekum et al. 1991). This speciesis one of the largest of the carangid fishes, measuring up to 170 cm total length (Lieske and Myers 1994). The world angling record (IGFA) is 66 kg (Smith-Vaniz 1984), and the largest published weight for this species is 86.6 kg (Murakami et al. 2007). This species can live to at least 20 years of age and has been recorded to 30 years of age in captivity (Friedlander and Dalzell 2004). Sudekum et al. (1991) determined females of this speciesreach maturity at approximately 60 cm (SL) and 3-4 years of age. However, Tharwat and Al-Gaber (2006) observed maturity to occur around is 37 cm in length (sex unknown). This species forms spawning aggregations which have been observed on shallow seaward reefs and offshore banks (Sudekum et al. 1991, de Silva et al. 2014). Spawning takes place during the summer months (peak May-August) in Hawaii (Friedlander and Dalzell 2004, Meyer et al. 2007). In Kaneohe Bay, Hawaii, juveniles less than 20 cm, occurred on the murky lagoon floor (Wetherbee et al. 2004). When juveniles reached 25 to 40 cm in length, they moved to the lagoonal patch reefs. Once larger than 40 cm, juveniles and subadults moved outside of the bay.
Giant trevally threats
This specieshas experienced declines in more human-populated areas in some parts of its range due to fishing (DeMartini et al. 2002, Meyer et al. 2007). This species is relatively long-lived and has a large maximum body size, which may make it more sensitive to fishing pressure. However, significant global population declines have not yet been observed and are not suspected due to exploitation.