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Four-Spotted Flounder fish identification, Habitats, Fishing methods, fish characteristics
The Four-Spotted Flounder, Paralichthys oblongus, also called American Four-Spotted Flounder or simply Four-Spot, is a flatfish and member of the left-eyed flounder family Paralichthyidae, which includes the sand flounders and sand dabs. This flounder are characterized by four large, oblong, and very conspicuous black eye spots edged with pale pinkish, two of them situated at each margin of the body. Its maximum size is 41 cm total length. Four-Spotted Flounder inhabits bays and sounds in the northern part of the range in progressively deeper water to 275m. Due to its rarity the Four-Spotted Flounder is deemed to be of limited value. It is considered to be an excellent food fish and is sold commercially.
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The Four-Spotted Flounder ranges in the western Atlantic from the coastal waters of Gulf of Maine, as far north as Nova Scotia, south to Florida, southern angle of Cape Cod, found in all Mexican waters. They occur between the eastern part of Georges Bank and the coast of South Carolina, along the continental shelf as far eastward as the general offing of Nantucket, in the northern shore of Massachusetts Bay. Its center of abundance appears to lie between southern New England and Delaware Bay.
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Description:
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Four-Spotted Flounder has comparatively elongate, strongly compressed body. Head length is 25% of the standard length; body depth is 50-60% of the body length. Eyes are large, longer than snout, nearly 25% to 30% in head, separated by a prominent, narrow, elevated, bony sharp ridge, narrower than pupil, anteriorly scaleless, and curved behind the upper eye posteriorly. The Four-Eye Flounder has long, large, oblique mouth with small, equally sized teeth; the lower jaw is not projecting. The teeth are sharp and well developed. Upper jaw with very numerous small, close-set teeth laterally, and 4 or 5 canines in front; each side of lower jaw with 7 to 10 teeth, the anterior rather long, about equal to anterior teeth of upper jaw; lateral teeth of upper jaw becoming gradually smaller the anterior, much larger, less numerous, and more widely set than in other species of this genus.
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Maxillary is very narrow, reaching opposite posterior border middle of pupil. The length of the maxillary is half the length of the head. Gape curved; gill rakers are short and toothed behind. The Four-Eye Flounder has a pointed and as long as head length caudal fin, short pectoral fins, and smooth scales. Scales are moderate, weakly, ctenoid or cycloid. Dorsal fin is very low, beginning above middle of eye, some of the anterior rays not longer than others, the middle rays a little longer than longest of anal rays the longest rays. The lateral line is strongly arched above the pectoral fins and extends into the head with branches to the upper eye and to below the lower eye.
Key characters
4 large, oblong, distinct, symmetrically-arranged black eye spots edged with pale pinkish, two of them situated at each edge of the body. Blind side may be as dark as eyed side. The dorsal fins originate before the eyes. Upper jaw extends to posterior portion of lower eye. The large mouth extends into the eyes and has a single row of teeth with large canines. There are small, smooth scales on both sides and an arched lateral line over the pectoral fins, originating just behind the eyes and extending to the caudal base. Body is moderately deep.
72 to 77 Dorsal fin rays
60 to 63 Anal fin rays
90 to 93 Scales
Gill rakers 2 to 8
Maximum size 16 in (41 cm).
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Four-Spotted Flounder is light brown to dark gray, brownish, somewhat mottled, with 4 very large horizontally oblong and quite conspicuous black "eye-like" spots, each consisting of a dark central mass and edged with a much lighter pinkish color; the dark spots often have small white centers. Two of the spots situated at each margin of the body, 1 just behind middle of the body below the dorsal, 1 opposite this above anal, 2 similar smaller spots below last rays of dorsal and above last of anal. Vertical fins are reddish-brown, with a few small, round dark and white spots. There are on the side many small ocelli, smaller than the eye, and numerous small black spots on head; the fins are mottled with black, and the first dorsal lobe may be quite black. The small markings on the body disappear with age. The underside is pale pinkish, almost translucent in certain areas. Its translucency of coloration indicates that it lives in deeper water than the other species of the genus. As most members of the left-eye flounders Four-Spotted Flounder can change the color and pattern of their eyed side to match the surrounding bottom, and are also capable of rapidly burrowing into muddy or sandy bottoms.
Four-Spotted Flounder very closely resembles the summer flounder. Most obvious difference is that its mottled gray back is invariably marked with four large, oblong, and very conspicuous black eye spots edged with pale pinkish, two of them situated at each margin of the body. Also Four-Spotted has 72 to 81 dorsal and 60 to 67 anal rays while summer flounder has 85 to 94 dorsal and 60 to 73 anal rays. This is also a much smaller fish than the summer flounder, for the adult’s average only about 12 inches long with the maximum length 16 inches. The Four-Spot can also be identified from the Summer Flounder by its slightly more elongated shape and proportionately larger eyes.
Habitats:
Four-Spotted Flounder preferring water depths of at least 22 meters and as far out as to the continental shelf. It does not usually come into as shoal water as the summer flounder often does. Most have been generally found in the first 700 feet of the water column over sandy and muddy bottoms, from about 42 meters down to at least 275 meters in waters 8.9 to 13.9 °C.
Four-Spotted Flounder is active during daylight hours and feeds during the day. Its feeds on amphipods, mysids, and shrimps, shellfish, and worms, are much the same as the summer flounder. Adults (greater fish than 20 cm in lengths) are predatory and mostly preying on crabs, squids, and chiefly small fishes such as sand lance and Atlantic silverside.
Spawning:
Four-Spotted Flounder spawns from May until mid-July with peak spawning in July. Spawning begins in the southern portions of the range and progresses northward in response to increasing water temperatures. Females mature at ranged in size from 15 to 42 cm total length. The period of incubation at a temperature varying from 51° to 54° F. is about 8 days. The eggs are buoyant, 0.95 to 1.05 mm. in diameter, with a single oil globule of 0.16 to 0.19 mm. An aggregation of pigment over the rear part of the trunk, combined with deep outline and a large head are distinctive for this species. Small fry of 2 to 3 inches have been seen in autumn, evidence that the fry of this flounder complete their metamorphosis and take to bottom about 3 months after they are hatched.
Fishing:
The Four-spotted flounder is most often taken commercially by fishing trawlers. Due to its small size, its rarity and lack of abundance inshore it is not prized or even well known by recreational anglers who may often mistake this flounder for its relative the Summer Flounder, as it shares a similar offshore range, appearance, and feeding habits. The meat is white and considered to have a very mild taste like that of the Summer flounder and Southern flounder. This is a fair table fish, and it is considered to be an excellent food fish and is sold commercially.
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