Japanese Spanish Mackerel fish identification, its habitats, characteristics, fishing methods.
The Japanese Spanish mackerel is a species of true mackerel in the scombrid family (Scombridae), very important commercially and ecologically, they become one of the main capturing targets of fishers in the East China Sea and Yellow Sea. Their maximum reported length is 100 cm, and the maximum reported weight is 7.1 kg.
Japanese Spanish mackerel, Scomberomorus niphonius, also known as Japanese seerfish, Thazard oriental in France, Carite oriental in Spain, Sagoshi, Sawara in Japan, Yaponskaya korolevskaya makrel in Russia, is an epipelagic, neritic species, widely distributed in subtropical and temperate waters of China, Japan and Korea. Confined to the subtropical and temperate waters of China, the Yellow Sea and Sea of Japan north to Vladivostock, former USSR.
Japanese Spanish mackerel have elongate, strongly compressed body. Snout much shorter than rest of head; posterior part of maxilla exposed, reaching to a vertical from hind margin of eye; sharp, compressed, triangular teeth in upper and lower jaws; patches of fine teeth on palatines and vomer; no teeth on tongue. 11 to 15 Gill rakers on first gill arch: 2 or 3 on upper limb and 9 to 12 on lower limb. First dorsal fin with 19 to 21 spines; second dorsal with 15 to 19 rays, followed by 7 to 10 finlets; anal fin with 16 to 20 rays followed by 6 to 9 finlets; pectoral fin rays 21 to 23. Vertebrae 48 to 50, usually 49 in total: 21 to 23 precaudal plus 27 or 28 caudal.
They are the only species in the genus with a straight intestine. Lateral line is gradually curving down toward caudal peduncle. Body with 7 or more rows of longitudinal spots on the sides; some spots connected together; spots more numerous and smaller, about pupil size; anterior quarter of first dorsal fin and a narrow distal margin of the rest of the dorsal fin black, most of basal membranes of posterior three quarters of fin white.
Distinguishing characteristics: This is the only species in the genus with a straight intestine. Lateral line gradually curving down toward caudal peduncle. Swim bladder absent. Body covered with small scales. Interpelvic process small and bifid.
19–21 Dorsal spines
15-19 Dorsal soft rays
16–20 Anal soft rays
Maximum length: 103 cm
Maximum weight: 9.4 kg
Their sides with 7 or more rows of longitudinal spots on the sides; some spots connected together; spots more numerous and smaller than in S. munroi, about pupil size. Anterior quarter of first dorsal fin and a narrow distal margin of the rest of the dorsal fin is black, most of basal membranes of posterior three quarters of fin white.
Japanese Spanish mackerel found near shore including semi-enclosed sea areas. They are an epipelagic, neritic species, carrying out a spawning migration in spring (March to June) and a feeding migration in fall (September to November) in the Inland Sea of Japan. Japanese Spanish mackerel utilizes near-shore or estuarine habitat as nursery areas for larvae and juveniles after wintering migrations following predictable route.
Japanese Spanish mackerel feed on small fishes. They are daylight feeders and exhibited piscivorous habits from first feeding both in the sea and in captivity. Feeding activity peaked at dusk; the species is known to prey on small fishes. Spanish mackerel is an exclusively piscivorous species from the very first feeding. Their morphological characteristics, such as a large mouth with teeth and digestive physiology, are adapted to early piscivory, but yet they form schools from juvenile to adult stage both in the wild and in captivity.
Japanese Spanish mackerel spawn from April to May with medium-sized fish producing some 550 000 to 870 000 eggs. Females became mature at 60 cm length and males at 40 cm length. Longevity is estimated to be six years, and maximum length is 103 cm. Generation length is therefore estimated to be approximately 2–3 years.
Japanese Spanish mackerel utilizes near-shore or estuarine habitat as nursery areas for larvae and juveniles after wintering migrations following predictable route. 5-6 days after hatching, the larvae can swim initiatively and begin to prey. The strong swimming ability of larvae might counteract the passive transportation along coast by ocean currents. The species may choose the strategy to retention of larvae in spawning grounds. This strategy may limit the gene flow between distant spawning populations.
Japanese Spanish mackerel larvae exhibit almost complete piscivory from the first feeding stage and begin to cannibalize under lack of piscine prey. Newly hatched larvae commenced feeding on fish prey (red sea bream Pagrus major larvae) on day 6 (after hatching) and completed yolk sac absorption by day 9 at 18.5 °C.
Japanese Spanish mackerel is anticipated to be an important target for sea-farming because of a high growth potential (reaching 10 mm TL in one month and 600 mm TL in the first growing season: from May to November). However, intensive cannibalism during the larval stages has prevented their mass production.
Driftnets and set gillnets are the major fishing gears in the seasonal fishery in the Inland Sea of Japan operational from March to June and from September to November.
The fish are primarily marketed fresh, and are especially tasty in winter.