Bullet Mackerel

Catches of Auxis are usually not identified to species because of current problems in identification. It may, however, be assumed that the Pacific and Indian Ocean catches reported by Japan, the Philippines and the Maldives are predominantly A. thazard . In the period from 1977 to 1980 these catches almost doubled to 122 995 metric tons, particularly due to increased landings by the Philippines, but decreased to about 98 000 metric tons 1981 (FAO, 1983). The total catch in 1996 (Auxis rochei and A. thazard ) was 172 693 t. Mainly Philippines 88 969 t. No catch in 1999

Pectoral fins short, but reaching past vertical line from anterior margin of scaleless area above corselet: corselet well developed and narrow in its posterior part (no more than 5 scales wide under second dorsal fin origin). Colour: a pattern of 15 or more narrow, oblique to nearly horizontal, dark wavy lines in the scaleless area above lateral line.

Probably cosmopolitan in warm waters but there are only a few documented occurrences in the Atlantic Ocean.

Maximum fork length from driftnet records in the Indian Ocean is 51 cm, but off Sri Lanka it is 58 cm; the common size in catches ranges between 25 and 40 cm, but depends on the type of gear used, and may also vary seasonally and by region. Size at first maturity is reported at about 29 cm fork length in Japanese waters, but about 35 cm around Hawaii. The species grows larger than Auxis rochei .

An epipelagic, neritic as well as oceanic species. In the eastern Pacific, mature fish occur throughout the year, though off Costa Rica spawning is heaviest from December through April, while in Japanese waters it peaks in July as expressed by the index of sexual maturity (Yasul, 1975). In the southern Indian Ocean, the spawning season extends from August to April; north of the equator it is reported from January to April. Fecundity was estimated at about 1.37 million eggs per year in a 44.2 em long female. Fecundity of fish in Indian waters ranged between approximately 200 000 to 1.06 million eggs per spawning in correlation with size of females. For other pertinent information on the biology see generic section on Auxis .

This species is distinguished by the following characters: a robust body, elongated and rounded; teeth small and conical, in a single series; total gill rakers on first gill arch 36-42; dorsal fins 2, D1 X-XII, separated from the second by a large interspace (at least equal to length of first dorsal-fin base), second dorsal fin followed by 8 finlets; anal fin followed by 7 finlets; pectoral fins short, but reaching past vertical line from anterior margin of scaleless area above corselet; a large single-pointed flap (interpelvic process) between pelvic fins; body naked except for the corselet, which is well developed and narrow in its posterior part (no more than 5 scales wide under second dorsal-fin origin); a strong central keel on each side of caudal-fin base between 2 smaller keels. Colour of back bluish, turning to deep purple or almost black on the head; a pattern of 15 or more narrow, oblique to nearly horizontal, dark wavy lines in scaleless area above lateral line; belly white; pectoral and pelvic fins purple, inner sides black (Ref 9684).

Epipelagic in neritic and oceanic waters (Ref. 9340). Feeds on small fish, squids, planktonic crustaceans (megalops), and stomatopod larvae (Ref. 5213). Because of their abundance, they are considered an important element of the food web, particularly as forage for other species of commercial interest. Preyed upon by larger fishes, including other tunas (Ref. 9987). Confined to oceanic salinities with strong schooling behavior. Though larvae have a high temperature tolerance (at least between 21.6 and 30.5°C), the widest among tuna species studied, their optimum temperature is between 27 and 27.9°C.

Dorsal spines (total): 10 - 12; Dorsal soft rays (total): 10 - 13; Analspines: 0; Analsoft rays: 10 - 14

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.

In correlation with temperature and other environmental changes, the spawning season varies with areas, but in some places it may even extend throughout the year.

Bomolochus Disease. Parasitic infestations (protozoa, worms, etc.)

Callitetrarhynchus Disease. Parasitic infestations (protozoa, worms, etc.)

Phyllodistomum Disease. Parasitic infestations (protozoa, worms, etc.)

Colocynotrema Disease. Parasitic infestations (protozoa, worms, etc.)

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

Phacelotrema Disease. Parasitic infestations (protozoa, worms, etc.)

Didymozoon Disease. Parasitic infestations (protozoa, worms, etc.)

Tergestia Disease. Parasitic infestations (protozoa, worms, etc.)

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

Hexostoma auxidi Disease. Parasitic infestations (protozoa, worms, etc.)

Adults are epipelagic in neritic and oceanic waters (Ref. 9340). They feed on small fish, squids, planktonic crustaceans (megalops), and stomatopod larvae (Ref. 5213). Because of their abundance, they are considered an important element of the food web, particularly as forage for other species of commercial interest. They are preyed upon by larger fishes, including other tunas (Ref. 9987). Marketed fresh and frozen (Ref. 9340) and also utilized dried or salted, smoked and canned (Ref. 9987).

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

廣泛分布於世界各熱帶及亞熱帶海域。包括地中海。台灣各海域皆產，尤其是東部及南部海域。

各沿岸國重要之食用魚，每年全世界之產量可達10-50萬公噸。一般漁法以圍網、定置網、流刺網、一支釣、延繩釣等等。煎食、味噌湯或加工成製品皆宜。

體紡錘形，橫切面橢圓形，背緣和腹緣略弧形隆起；尾柄細強，兩側在尾鰭基部各具一中央隆起脊和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，上下頜各具一列細小尖銳齒。鋤骨、腭骨和舌上均無齒。第一鰓弓上之鰓耙數為36-42。體在胸甲部被圓鱗，胸甲部鱗向後延伸止於第一及第二背鰭間中部之下方，其餘皆裸露無鱗；左右腹鰭間具1大鱗瓣；側線完全，沿背側呈波形彎曲延伸，伸達尾鰭基。第一背鰭具硬棘X-XII，與第二背鰭起點距離遠，其後具8個離鰭；臀鰭與第二背鰭同形；尾鰭新月形。體背側藍黑色，腹部淺灰色，體背側在胸甲後方具不規則之蠕蟲紋斑。

近海大洋性中表層洄游魚種。群游性，游泳速度快。以鯡、鯷等小魚及烏賊為食。

The frigate tuna, frigate mackerel or alagaduwa (Auxis thazard) is a species of tuna, in the family Scombridae, found around the world in tropical oceans. The eastern Pacific population is now regarded as a separate species by some authorities, Auxis brachydorax.

This schooling species occurs at temperatures ranging from 27 to 27.9 °C. Epipelagic in both coastal and oceanic waters (Ref. 9340). Because of their abundance, they are considered an important element of the food web, particularly as forage for other species of commercial interest. It grows larger than @A. rochei@. Feeds on small fish, squids, planktonic crustaceans (megalops), and stomatopod larvae (Ref. 5213). Preyed upon by larger fishes, including other tunas (Ref. 9987). Also caught with troll lines. Marketed fresh and frozen (Ref. 9340), also utilized dried/salted, smoked and canned (Ref. 9987).

Atlantic, Indian and Pacific oceans