Eel fish japan

Eel fish japan Body elongate, cylindrical anteriorly, compressed posteriorly, fleshy and smooth. Mouth nook extending to posterior margin of eyes. Lower jaw barely longer than top. Lips with fold, symmetrical. Snout depressed and stout.

Distance among dorsal fin beginning and vent varies from to 13.five in keeping with cent of general frame period. Head period 11.2 to 11.nine in keeping with cent in frame period. Upper jaw period contained from three.

7 to 4.three instances in head period. Length of pectoral fin from 2.2 to three.7 in keeping with cent of head period. Teeth small, conical, in cardiform bands on jaws and vomer. Maxillary enamel in a slender band.

Vomerine enamel band barely broader and longer than (or as lengthy as) that of maxillary (Chen & Weng, 1967). Dorsal and anal fins confluent with caudal fin. Distance among origins of dorsal and anal shorter than head period.

Body protected with rudimentary imbedded scales which organized in small corporations and positioned obliquely at proper angles to the ones of neighboring corporations. Plain-colored, now no longer marbled or mottled. Specimens in alcohol are uniformly darkish brown at the lower back and lighter at the belly. 114 to 117 vertebrae

Historical background

Eel aquaculture commenced in Tokyo, Asia in 1879, with the elevating of elvers, at the same time as Taiwan Province of China

and the Republic of Korea initiated eel way of life in 1968 and the People`s Republic of China in 1975. The eel farmers of China are fundamental producers, the various farms being located in Guangdong province; a massive percentage are exported stay or as kabayaki to Japan.

With an annual call for of one hundred thirty 000 heaps, Japan constitutes the maximum vital eel marketplace withinside the world; its very own manufacturing (specifically from aquaculture), however, is inadequate to cowl call for.

The distinction is specifically imported from China, Taiwan Province of China, the Republic of Korea and Malaysia.

Habitat and biology Eel fish japan

Young Japanese eels input rivers in small shoals from February to May, and ascend to the top reaches of rivers and mountain lakes. After numerous years in freshwater and with the onset of sexual maturity, the eels migrate downstream and input the ocean from to .

However, a few Japanese eels have in no way entered freshwater (sea eels); in reality 3 one of a kind classes of eels are located, every with a one of a kind migratory history: river eels, estuarine eels and sea eels.

Anguilla japonica has a bendy sample of migration, with an cappotential to conform to numerous habitats and salinities. Anguillid eel migrations into freshwater are certainly now no longer an compulsory migratory pathway, and this shape of diadromy must be described as facultative catadromy, with the ocean eel as one in all numerous ecophenotypes.

Adults feed on benthic crustaceans, bony fish and insects. Japanese eels have very comparable migratory and recruitment patterns to European eels.

Production structures Eel fish japan

The manufacturing of eels is primarily based totally on wild catches of glass eels (elvers) which are used for in addition on-growing. Glass eels and elvers are pleasant cultured in indoor tanks earlier than being moved into grow-out facilities. Gro-wout of elvers to marketplace length may be finished in both tank structures or earthen ponds. Seed supply

Glass eels are captured across the seashorelines of China, Taiwan Province of China, the Republic of Korea and Malaysia, and are both used nationally or exported to eel farmers in different nations.


At first the glass eels (~zero.2 g every) are stored in smaller tanks of 80-a hundred m3 for quarantine purposes. The density at this level is zero.three-zero.five kg/m3. Water temperature is stored strong at 25-29 ºC. The eels are tested for illnesses and, following diagnosis, treated.

They also are weaned onto synthetic diets with bloodworm and, later on, dry starter feed. When the eels attain about five g they’re transferred to a juvenile manufacturing unit with large tanks (three hundred-six hundred m³) at stocking densities of kg/m2. At this factor the eels can digest dry feed pellets (1 mm).

Extensive pond structures

The conventional shape of eel way of life withinside the People’s Republic of China is in earthen ponds, which must be built on non-porous soils.

It is feasible to line ponds so they do now no longer leak; however, the expenses of creation are higher. Ponds variety in length from three 000-five 000 m2, and are 1 to m deep. When eels attain marketable length, they’re transferred to large ponds (five 000-10 000 m2).

The ponds can be static or flow-through. The pleasant temperature variety in ponds is 20-30 ºC. Individual boom charges range substantially; grading each 5 weeks is important a good way to attain a excessive ordinary boom performance.

Cement tanks structures

These structures include rectangular or round tanks from a hundred-three hundred m2, normally constructed of cement. The eels are stocked at a length of fifty g. Densities attain as much as 1-five kg/m2. Extruded dry feed (1.five-three mm) is fed numerous instances a day. Grading each 6-7 weeks is important.

Feed supply

Eel feeds are eel2 excessive carbohydrate (approximately 22 Eel fish japan

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