The largehead hairtail (also beltfish), Trichiurus lepturus, is a member of the cutlassfish family, Trichiuridae. It is a long, slender fish found throughout the tropical and temperate waters of the world. The Atlantic and Pacific populations are also known as Atlantic cutlassfish and Pacific cutlassfish, respectively.
Largehead hairtails can grow to 2.34 m (7.7 ft) in length; the largest recorded weight is 5 kg (11 lb) and the oldest recorded age is 15 years. They prefer coastal regions and sometimes enter estuaries. They are found at depths of 0 to 589 m (0 to 1,932 ft) with most records between 100 and 350 m (330 and 1,150 ft).
Juveniles participate in the diel vertical migration, rising to feed on krill and small fish during the day and returning to the sea bed at night. This movement pattern is reversed by large adults, which mainly feed on fish. Other known prey items include squid and shrimp, and the highly carnivorous adults regularly cannibalise younger specimens.
Spawning depends on temperature as the larvae prefer water warmer than 21 °C (70 °F) and are entirely absent at less than 16 °C (61 °F). Consequently spawning is year-round in tropical regions, but generally in the spring and summer in colder regions.
Fisheries and usage
Largehead hairtail is a major commercial species. With reported landings of more 1.3 mill. tonnes in 2009, it was the 6th most important capture fish species. By far the largest catches were reported by China (1.2 mill. t.) from the NW Pacific (FAO Fishing Area 61); other countries reporting significant catches were South Korea, Japan, and Pakistan.
In Korea, the largehead hairtail is called "갈치 (Kalchi):sword fish",in which "갈(Kal)" means sword and "치(chi)" means fish, and is popular for frying or grilling. In Japan, where it is known as tachiuo ("太刀(tachi)":sword, "魚(uo)":fish), they are fished for food and eaten grilled or raw, as sashimi. They are also called "sword-fish" in Portugal and Brazil (peixe-espada), where they are eaten grilled or fried. Its flesh is firm yet tender when cooked, with a moderate level of "fishiness" to the smell and a low level of oiliness. The largehead hairtail is also notable for being fairly easy to debone.
- Froese, Rainer and Pauly, Daniel, eds. (2015). "Trichiurus lepturus" in FishBase. February 2015 version.
- Bittar; Awabdi; Tonini; Vidal Junior; and Madeira Di Beneditto (2012). Feeding preference of adult females of ribbonfish Trichiurus lepturus through prey proximate-composition and caloric values. Neotrop. ichthyol. 10(1).
- Martins, A.G.; and Haimovici, M. (2000). Reproduction of the cutlassfish Trichiurus lepturus in the southern Brazil subtropical convergence ecosystem. Scientia Marina 64(1): 97-105.
- FAO (Food and Agriculture Organization of the United Nations) (2011). Yearbook of fishery and aquaculture statistics 2009. Capture production (PDF). Rome: FAO. pp. 27, 202–203.