Bonito

The reported world catch (eight countries) for the period between 1975 and 1981 fluctuated between about 44 000 and 65 000 t per year. The 1977 catches were exceptionally high, almost 84 000 t. About 67 500 t were reported for 1981 (FAO, 1983). The countries with the largest landings were the Philippines, Malaysia and Pakistan. In India, E. affinis is an important species in local drift net (gillnet) and hooks and lines fisheries, even though this country has not supplied separate statistics for it during the above period. Typically these are multispecies fisheries also taking E. affinis. Besides gillnetting, trolling is the major fishing technique in use. Occasionally beach seines and longlines are also deployed. Some gear types are rather size-selective, i.e. trolling lines take smaller fish than gillnets. The meat is of good quality when fresh, but it deteriorates very fast if not treated adequately.The total catch reported for this species to FAO for 1999 was 169 607 t. The countries with the largest catches were Malaysia (57 281 t) and Thailand (45 768 t).

Throughout the warm waters of the Indo-West Pacific, including oceanic islands and archipelagos.A few stray specimens have been collected in the eastern tropical Pacific.

Gillrakers 29 to 33 on first arch; gill teeth 28 or 29; vomerine teeth absent. Anal fin rays 13 or 14. Vertebrae 39; no trace of vertebral protuberances; bony caudal keels on 33 and 34 vertebrae. Colour: dorsal makings composed of broken oblique stripes.

Maximum fork length is about 100 cm and weight about 13.6 kg, common to 60 cm. The all-tackle angling record is a 11.80 kg fish from Merimbala, New South Wales, with a fork length of 96.5 cm taken in 1980. In Philippines waters, maturity is attained at about 40 cm fork length, while in the Indian Ocean it is reached between 50 and 65 cm in the 3rd year of age.

An epipelagic, neritic speciesinhabiting waters temperatures ranging from 18 to 29° C. Like other scombrids, E. affinis tend to form multispecies schools by size, 'i.e. with small Thunnus albacares, Katsuwonus pelamis, Auxis sp., and Megalaspis cordyla (a carangid), comprising from 100 to over 5 000 individuals. Although sexually mature fish may be encountered throughout the year, there are seasonal spawning peaks varying according to regions: i.e. March to May in Philippine waters; during the period of the NW monsoon (October-November to April-May) around the Seychelles; from the middle of the NW monsoon period to the beginning of the SE monsoon (January to July) off East Africa; and probably from August to October off Indonesia. The only available information on fecundity applies to Indian Ocean material: a 1.4 kg female (ca 48 cm fork length) spawns approximately 0.21 million eggs per batch (corresponding to about 0.79 million per season), whereas a female weighing 4.6 kg (65 cm fork length) may spawn some 0.68 million eggs per batch (2.5 million per season). The sex ratio in immature fish is about 1:1, while males predominate in the adult stages. E. affinis is a highly opportunistic predator feeding indiscriminately on fish, shrimps and cephalopods.In turn, it is preyed upon by marlins and sharks.

This species is distinguished by the following characters: medium-sized fish with a robust, elongate and fusiform body; teeth small and conical, in a single series; total gill rakers on first gill arch 29-34; D1 XI-XIV with both dorsal fins separated by only a narrow interspace (not wider than eye), anterior spines of first fin much higher than those midway, giving fin a strongly concave outline; D2 much lower than first and followed by 8-10 finlets; anal fin followed by 6-8 finlets; pectoral fins short, never reaching interspace between dorsal fins; 2 flaps (interpelvic process) between pelvic fins; very slender caudal peduncle with a prominent lateral keel between 2 small keels at base of caudal fin; body naked except for corselet and lateral line. Colour of back dark blue with a complicated striped pattern which does not extend forward beyond middle of first dorsal fin; lower sides and belly silvery white; several characteristic dark spots between pelvic and pectoral fins (but may not always be present) (Ref. 9684, 90102).Description: Swim bladder absent; no trace of vertebral protuberances; dorsal rays X-XV+11-15+8-10 finlets; anal rays 11-15+6-8 finlets; pectoral rays 25-29; maxilla extending posterior to middle of eye; jaw teeth are small and conical, about 25-35 on each side of lower jaw; presence of palatine teeth, none on vomer (Ref. 90102).

Anisakis Disease (juvenile). Parasitic infestations (protozoa, worms, etc.)

Caligus Infestation 2. Parasitic infestations (protozoa, worms, etc.)

Lecithochirium Infestation. Parasitic infestations (protozoa, worms, etc.)

Prosorhynchoides Infestation 2. Parasitic infestations (protozoa, worms, etc.)

Spinitectus Infestation. Parasitic infestations (protozoa, worms, etc.)

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 10 - 15; Dorsal soft rays (total): 11 - 15; Analspines: 0; Analsoft rays: 11 - 15; Vertebrae: 39

Like other scombrids, E. affinis tend to form multispecies schools by size especially with small T. albacares, K. pelamis, Auxis sp. and M. cordyla comprising from 100 to over 5,000 individuals. But during certain periods of the year, there is a tendency for the fish to remain scattered (Ref. 168). Kawakawa is piscivorous. Most important prey items of the immature smaller E. affinis were the larval anchovy and lanternfish while the matured fish Decapterus spp and Scomber australicus (Ref. 53677).

Occurs in open waters but always remains close to the shoreline. The young may enter bays and harbors. Forms multi-species schools by size with other scombrid species comprising from 100 to over 5,000 individuals. A highly opportunistic predator feeding indiscriminately on small fishes, especially on clupeoids and atherinids; also on squids, crustaceans and zooplankton. Caught in multispecies fisheries, mainly by surface trolling; also with gill nets. Generally marketed canned and frozen; also utilized dried, salted, smoked and fresh (Ref. 9684).

fisheries: highly commercial; gamefish: yes; price category: medium; price reliability: reliable: based on ex-vessel price for this species

分布於印度-西太平洋之溫暖水域。台灣主要產於東部海域。

為各沿岸國重要之經濟魚種，年產量可達45,000-65,000公噸。一般漁法以流刺網或延繩釣捕獲。主要以煎食、味噌湯為食，新鮮魚可作生魚片。

體紡錘形，橫切面近圓形，背緣和腹緣弧形隆起；尾柄細短，平扁，兩側各具一發達的中央隆起脊，尾鰭基部兩側另具2條小的側隆起脊。頭中大，稍側扁。吻尖，大於眼徑。眼較小，位近頭的背緣。口中大，端位，斜裂；上下頜等長，上下頜齒絨毛狀；鋤骨和腭骨亦具細齒1列，舌上則無齒。第一鰓弓上之鰓耙數為29-34。體在胸甲部及側線前部被圓鱗，其餘皆裸露無鱗；左右腹鰭間具2大鱗瓣；側線完全，沿背側延伸，稍呈波形彎曲，伸達尾鰭基。第一背鰭具硬棘XI-XV，與第二背鰭起點距離近，其後具8-10個離鰭；臀鰭與第二背鰭同形；尾鰭新月形。體背側深藍色，有十餘條暗色斜帶；胸部無鱗區常具3-4個黑色暗斑。全世界本屬共有三種，台灣僅產此種。

近海大洋性上層洄游魚類。常成大群游動，流泳速度快。主要攝食魚類、甲殼類、烏賊等。

Occurs in open waters with temperatures ranging from 18° to 29°C but always remains close to the shoreline. The young may enter bays and harbors. Form multispecies schools by size with other scombrid species comprising from 100 to over 5,000 individuals. A highly opportunistic predator feeding indiscriminately on small fishes, especially on clupeiods and atherinids; also on squids,crustaceans and zooplankton (Ref. 9684). Generally marketed canned and frozen; also utilized dried, salted, smoked (Ref. 9684) and fresh (Ref. 9987).

Known from seamounts and knolls