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Kamchatka flounder fish identification, Habitats, Fishing methods, fish characteristics
The Kamchatka flounder, Atheresthes evermanni, is a flatfish of the family Pleuronectidae. It is a demersal fish that lives at great depths of between 20 m (66 ft) and 1,200 m (3,900 ft) , but in the summer live in the middle of the water column. It can grow as long as 1m (39 in) in length, and can weigh up to 8.5 kilograms (19 lb). The average life is up to 30 years. Its native habitat is the far Northern Pacific, from the southern Alaskan coast and the Aleutian Islands, across the Bering Sea, to the Kamchatka Peninsula and the Sea of Okhotsk.
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The Kamchatka flounder (Atheresthes evermanni), also known as Arrowtooth halibut, Halibut strelozuby Asian, Abura-garei, Палтус Стрелозубый Азиатский (in Russian), is a relatively large flatfish which is widely distributed from Northern Japan, Sea of Japan through the Sea of Okhotsk to the Western Bering Sea, Western Kamchatka north to Anadyr Gulf and east to the eastern Bering Sea shelf. In U.S. waters they are found in the Aleutian Islands and the Shelikof Strait in Alaska where they generally decrease in abundance from west to east.
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In the eastern part of their range, in the waters of the western Bering Sea, Kamchatka flounder overlap with Arrowtooth flounder (Atheresthes stomias, Halibut strelozuby American, Arasuka-abura-garei) which are very similar in appearance. Kamchatka Flounder slightly larger in size (the maximum length of 94 cm, while Arrowtooth flounder up to 84 cm) and have only a single row of teeth on lower jaw. They are well distinguished from each other provision of the left eye. The upper eye not reaching the upper profile of the head is not visible from the blind side, which is typical of the flatfish position. On Arrowtooth Flounder, one eye can be easily seen from the blind side of the body. The scales are more strongly ctenoid and the anterior nostril bears a long flap.
Description:
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They have elongated body, depth is 1/3rd of a length, and head length is 1/3rd in length, covered with relatively large, thin scales. Mouth is large with upper jaw reaching to or very slightly past the vertical from posterior margin of lower eye. Mouth armed with sharp, long and slender teeth with arrow-shaped points, in a single row on lower jaw, their length unequal. Teeth arranged in two rows on the upper and lower jaws; a double row of smaller teeth on side of upper jaw, the outer row the smaller; they grow larger anteriorly, become curved inward, fanglike and some of them depressible. 3+10 gill rakers rather slender, the longest a trifle less than half length of eye.
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Profile of snout on same curve with that behind eye; very slightly depressed above eye. The eyes are on one side of the body, scarcely reaching to upper profile, the lower one the more anterior. The upper eye is almost on the edge of the head. Interorbital appearing rather flat and moderately broad, the bone, however, narrow and convex, its width less than half diameter of pupil; nostrils close together, the posterior of eyed side in a broad, short tube, anterior in a narrower, longer tube; anterior nostril of blind side with a long flap nearly a third as long as upper eye, broadening toward its tip and becoming conspicuously opaque white; snout with many pores scattered among the irregularly placed scales.
Scales very finely ctenoid, the spinules short, fine, and numerous, only seen upon careful examination with a lens; many scales have only a few irregular spinules; others are entirely without them, appearing as if they had been rubbed off; head and body everywhere with numerous, small, cycloid supplementary scales crowded in; scales of blind side all cycloid; snout, mandible, maxillary, and interorbital with numerous small cycloid scales, those on latter extending out on eyeball to edge of iris; all fins rather closely covered with fine scales. Lateral line is straight, just slightly bending upward from opposite tip of pectoral. Pectoral of eyed side longer and more pointed than that of blind side; first ray of dorsal inserted above anterior margin of pupil; ventral short, scarcely reaching to front of anal. Caudal fin shallowly concave on posterior outline.
Key characters
Mouth large, upper jaw extends beyond the vertical center of the eye. The upper eye is almost on the edge of the head. Caudal fin slightly sinuate. Lateral line is straight. Arrow shaped teeth in 2 rows. Scales are cycloid.
98-116 dorsal soft rays
76 – 94 anal soft rays
109 scales
2-3 +9-12 gill rakers
50-52 vertebrae
Max length: 1 m; common length: 54.0 cm
Max. Weight: 8,500 g
Max. Age: 20 years
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Eye of the body is olive-brown to dark brown, without markings, light the blind side. Differ from most other fish from the family of flatfish more elongated body. The asymmetry of the skull is preserved, but it is expressed to a lesser extent than in plaice.
Habitats:
The Kamchatka flounder is a predatory benthic marine fish, Inhabits the sandy-muddy bottoms of continental slope and shelf in the great depths from 20 to 1200 m at a temperature of bottom waters from -0.3 to +10 °C. The maximum concentrations are confined to the isobaths of 300-700 m, but in the summer live in the middle of the water column. On the shelf rests mainly juveniles. The active predator: the composition of food in all areas dominated by fish, mainly Pollock, benthic crustaceans, shrimp and squid.
Spawning:
Reach sexual maturity between the ages of 7 to 17 years (usually 10-14 years). The males reach sexual maturity at 7 and up years, females - in 10 and up years. Spawning takes place during the cold season, in winter and spring - October to April at depths ranging from 120 to 1000 m at a water temperature of 2 to 10 °C. Females emit spawn at depths ranging from 300 to 1000 m at a temperature of 2-10 °C, the number of eggs varies from 300,000 to 3.5 million. The eggs are pelagic, large, thin, long, hatch at a temperature of 6 ° C after 16 days and undergo development with the conversion, as well as eggs of other flatfishes. A notable feature of the larvae is the presence of spines over the eyes and on the operculum, which are absent in the larvae of other halibut. The average life is up to 30 years. Males are at maximum performance smaller than females at 20-27 cm Lives up to 20 years.
Fishing Methods:
The flounder refers to commercial species, although the fat meat has a good taste of the intense watering.
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