New Jersey Scuba Diving
These fish all live and feed on the bottom, out in the open. Often they will hide in the sand with just their eyes visible, and most can change color to match their surroundings.
Flounders fall into three main groups: left-eyed, right-eyed, and soles. All of these are highly compressed, and actually lie sideways on one side of their bodies, with both eyes on the other side. Which side the eyes are on is an important distinguishing feature. There are dozens of other species of flounders found in the New Jersey area, this is just a listing of the larger, more common, and more interesting ones.
Flounders are born ( or hatched ) with one eye on either side of their head, like any normal fish. However, during the course of early development, one eye migrates over the top of the head to the other side, twisting the skull in the process. As this happens, the fish changes from an upright-swimming planktonic larva to a juvenile that lies on one side when it settles to the bottom. The upper side of the fish retains normal coloration, while the lower side becomes white.
In most species the eyes always migrate to the same side of the head. In some species neither side is preferred. Such species are known as ambidextrous, and both left and right individuals occur. Even in non-ambidextrous species, for a small percentage of individuals, things go wrong, and the eyes end up on the wrong side of the head. In Winter Flounders, this results in a fish with a normally colored head, but a white body ( I suppose the underside is brown. ) these unfortunate individuals stand out against the bottom like little white targets, and are quickly picked off by predators before they have a chance to grow. Keep a sharp eye when diving in the rivers early in the season and you may spot some of these inch-long oddities.
Flounders are true masters of camouflage, able to alter their coloration and even patterning at will. The two aquarium-bound Windowpanes at right were taken from light and dark bottoms and placed on contrasting sand. In a short time, they will match their new surroundings as perfectly as the wild specimen below.
In addition to this, flounders often also bury themselves, using a fluttering motion to cover themselves with a thin layer of sand, leaving just the eyes exposed. When concealed like this, they are almost impossible to detect, until they explode out from under you as you swim by !
usually much smaller
Soft sandy bottoms,
in depths from water's edge to 150 ft.
This is a left-eyed flounder. Identifying characteristics are the nearly circular body shape and the free rays of the dorsal fin, which form a frill near the eye. The Windowpane is common, but very thin and too small to eat. It is the sole new-world representative of the turbot family, which is commercially important in Europe.
Summer Flounder (Fluke)
to 37 " and 20 lbs.
usually much smaller
Paul G. Scarlett
Principal Fisheries Biologist
Bureau of Marine Fisheries
Estuarine and coastal waters from Nova Scotia to Florida. Most abundant between Cape Cod, Massachusetts and Cape Fear, North Carolina.
Summer flounder can grow to sizes of over 30 inches and can weigh more than 20 pounds. The sport fish state record was landed in 1953 and weighed 19 pounds, 12 ounces. Due to tremendous sport and commercial fishing pressure, summer flounder rarely survive long enough to achieve the maximum size. Females grow faster than males, and juvenile summer flounder can reach a length of 9 to 12 inches during their first year. Fourteen inch summer flounder are generally 2 or 3 years old and weigh about a pound. A twenty inch summer flounder is usually 4 years old or older and weighs about 3 pounds.
Food and Feeding:
Summer flounder are opportunistic feeders, with vision playing a primary role in prey selection and capture. The fish lies on the bottom partly concealed by sand and partly by its coloration, which can be changed to match the surrounding environment. When suitable prey appears, it rushes out and devours the victim. Summer flounder are swift swimmers and they sometimes pursue schools of small fish to the surface. Common prey of summer flounder include sand shrimp, Winter Flounder, blue crab, Bay Anchovy, Atlantic Silversides, squid, and killifish.
This is a left-eyed flounder. The five spots in an "X" pattern near the tail are one distinguishing feature, as well as the large toothy right-pointing mouth and widely-spaced eyes. Compare this head shot with the Winter Flounder below.
Summer flounder normally inhabit near-shore coastal and estuarine waters during the warmer months of the year and move offshore in depths of 100 to 500 feet of water during the fall and winter. A northward drift is also exhibited whereby fish return to more northern estuaries in successive years. This results in a higher occurrence of larger, older fish in the more northern parts of its range.
Estuaries and inshore oceanic water habitats are critically important to the life cycle of summer flounder. These areas are utilized for summer feeding grounds by adults and for nursery grounds by juveniles. Summer flounder prefer hard, sandy bottom, but can be found in salt marsh creeks and seagrass beds with muddy or silty substrate.
Spawning occurs during the fall and winter while the fish are moving offshore or at their wintering grounds. Offshore movement and spawning occur earlier in the northern part of the range. Larvae and post larvae drift and migrate inshore, entering coastal and estuarine nursery areas from October to May. Most summer flounder are sexually mature by age 3. Females can release as many as 4,000,000 eggs with egg numbers directly related to fish size. Summer flounder are serial spawners, with egg batches being continuously matured and shed during a protracted spawning season.
Unlike most other flatfishes, Fluke are not afraid to swim up into the water column, and can often be found perched on rocks and ledges well above the bottom.
Recreational and Commercial Importance:
Summer flounder is a highly prized food fish sought by both commercial and recreational fishermen. The majority of landings from the commercial fishery are taken by otter trawl during the winter when summer flounder are well offshore. During the 1980s, commercial fishermen landed an average of 4,700,000 pounds per year in New Jersey. Beginning in 1993, commercial landings have been controlled by a quota, with New Jersey commercial fishermen limited to 1.9 million pounds in 1998. This fish is also one of the mainstays of the sport fishery along the Atlantic coast, accounting for a large catch from bridges, jetties, and small boats as well as party and charter boats.
Summer flounder sport fishing occurs mainly within one mile of the coast, with the greatest activity in and around inlets. They can be caught while still fishing, drift fishing, casting from the beach and slow trolling. A common fishing outfit would include a five to six foot rod and aconventional reel filled with 10 to 20 pound test line. Summer flounder can be taken on large, long shanked hooks attached to a two to three foot leader, fished singly or in tandem. Because of their large mouth and aggressive nature, large hooks (4/0-6/0) work well and reduce the chances of gut hooking smaller fish that may be below the legal size limit. Three-way swivels and sinkers or weighted bucktails complete the rig. The use of live bait is common but summer flounder are also taken on squid, clams, jigs, small spoons and spinners. Although not as strong a fighter per pound as some other sport fish, summer flounder provide lively action, especially on light tackle. Recreational harvest in New Jersey is now controlled by size limits and bag limits. Since size and bag limits change annually, anglers must check current regulations.
Fluke can often be found perched high above the bottom on rocks and other structure. This is completely unlike Winter Flounder, which are never found off the bottom.
Able and Kaiser (1994); Bigelow and Schroeder (1953); Daiber, et al. (1976); Geiser (1977); Ginsburg (1952); Leim and Scott (1966); Long and Figley (1982); MAFMC (1990); Scarlett (1982); Shreaves ( personal communication )
This article first appeared in New Jersey Reef News - 1999 edition
See Restrictions and Health Advisories for season and catch limits.
to 25" and 8 lbs.
usually much smaller
Paul G. Scarlett,
Principal Fisheries Biologist
Bureau of Marine Fisheries
also called Flounder, Blackback, Black
Flounder, Georges Bank Flounder, Lemon
Sole, Sole, Flatfish, Rough Flounder and Mud Dab
Winter flounder live in estuarine and coastal waters from Labrador to Georgia. They are most common between Nova Scotia and New Jersey. Locally, winter flounder are most abundant in New Jersey's northern and central estuarine and near-shore coastal areas with numbers diminishing south of Barnegat Bay. Good populations of winter flounder can be found in Raritan Bay, Sandy Hook Bay, Navesink River, Shark River, Manasquan River and parts of the Barnegat Bay estuarine system.
Winter flounder can grow to sizes of more than 25 inches and weigh more than 8 pounds. The New Jersey sport fish state record was landed in 1992 and weighed 5 pounds, 11 ounces. Females grow faster than males and juvenile winter flounder can reach a length of about 6 inches during their first year. Twelve inch winter flounder are generally 3 years old and may weigh slightly more than a pound. In New Jersey, few winter flounder live past the age of 10.
Predators, Food and Feeding:
Natural predators of winter flounder include sharks, oyster toadfish, summer flounder, striped bass, monkfish and spiny dogfish. When feeding, a winter flounder will lie motionless, partly concealed on the bottom, with its head raised off the bottom, braced by the dorsal fin. When prey is sighted, the fish remains motionless, pointing toward the prey, then lunges forward and downward to capture it. This semi-hidden feeding behavior enables the fish to effectively capture prey while at the same time providing a hiding mechanism to protect the winter flounder from its predators. Winter flounder are sight feeders and feed during daylight. Throughout their range, winter flounder eat polychaete worms, amphipod and isopod crustaceans, clam siphon tips and plant material. They are omnivorous and opportunistic, eating whatever is available.
You seldom find them fully exposed like this.
This is a right-eyed flounder. The usually dark and even coloration, tiny
left-pointing mouth, and close-set eyes are identifying characteristics.
Compare this head shot with the Summer Flounder above.
In New Jersey, adult winter flounder usually inhabit near-shore coastal and estuarine waters from October through May. During the summer, they migrate just off the beach to several miles offshore. In the fall, most winter flounder return to the same estuary they inhabited the previous winter. Juveniles spend their first year in estuaries where they were spawned, after which they join the adult migration.
Estuaries and near-shore oceanic water habitats are critically important to the life cycle of winter flounder. These areas are used as wintering, summering and spawning grounds by adults and as nursery areas by juveniles. Winter flounder prefer sand or mud-sand mixture bottoms, but can be found in creeks and sea grass beds with muddy or silty substrates.
In New Jersey, winter flounder spawn in estuaries from February to April at temperatures of 1°C to 10°C and salinities ranging from 10 to 35 parts per thousand. Almost all winter flounder are sexually mature by 3 years of age. Females can release as many as three million eggs, with egg numbers directly related to fish size. When hatched, winter flounder larvae are about one-tenth of an inch long. Larvae are structurally similar to those of other fish species, with one eye on each side of the head. By the time the larvae reach a size of about one-half inch, the left eye has migrated to the right side of the body and the fish assume a true flatfish, bottom-associated existence.
Winter flounder are a highly prized food fish sought by both commercial and recreational anglers. The majority of landings from commercial fisheries are taken by otter trawl in the spring and fall. Commercial fishermen usually land between 200,000 and 300,000 pounds of winter flounder in New Jersey per year. These fish are also a mainstay of the inshore spring and fall sport fishery along the Atlantic coast. During the last 10 years, New Jersey's sport fishermen have harvested over 550,000 winter flounder per year. In terms of numbers, New Jersey annually ranks at or near the top of per state winter flounder harvest among all East coast states.
In a typical stalking pose.
The rivers are often crawling with baby flounders.
Winter flounder sport fishing occurs mainly within estuarine bays and rivers, usually from an anchored boat or the bank. A common fishing outfit would include a six foot light to medium action rod and a conventional or spinning reel filled with 6 to 10 pound test. Most freshwater fishing outfits also work well for winter flounder. Winter flounder can be taken on small (#10) long shanked hooks baited with clams, mussels or bloodworms. Whole kernel canned corn works well as bait and can also be used as chum, along with rice and crushed mussels. Stirring up the bottom under an anchored boat with heavy weights, an oar, or even a plunger fastened to a long pole will attract fish. Hooks can be fished singly, in a multiple hook rig or with spreaders, with sinkers heavy enough to hold bottom. Winter flounder can provide lively action, especially on light tackle. Recreational harvest in New Jersey is controlled by a season and size limit.
Bigelow and Schroeder (1953), Bowman, et al. (1976), Geiser (1977), NMFS (1999), Olla, et al. (1969), Pearcy (1962), Perlmutter (1947), Phelan (1992), Scarlett (1988, 1991, 1997), Scarlett and Allen (1992)
This article first appeared in New Jersey Fish & Wildlife Digest - 2000 Marine edition
See Restrictions and Health Advisories for season and catch limits. There is a long closed season for Winter Flounder, so if you plan to do any spearfishing, learn the differences between this and other species, especially Summer Flounder.
( literally: "horse tongue" )
to 8 ft and 700 lbs.
usually much smaller
The Atlantic Halibut is the largest member of flatfish family and has a grayish eyed side and white blind side. Juveniles are found along the coast of Norway and in relatively shallow waters, while full-grown halibut usually stay in deep waters, between 300 and 2000 meters. So don't expect to see one while diving.
Atlantic Halibut spawn at depths of 300-700 meters, in deep hollows in the banks off the coast and in the fjords. In addition to the coast of Norway, halibut also spawn off the Faeroe Islands, along the ridge between Greenland, Iceland and Scotland, in the Denmark Strait, in the Davis Strait and on the banks off Newfoundland.
"World Record" Atlantic Halibut - 255 lbs, caught in 1989,
location unknown. This fish must be over seven feet long !
Excessive commercial fishing has reduced Atlantic Halibut stocks to the point where they are now a by-catch fishery - no longer worth going after themselves. Surprisingly, Halibut are now successfully farmed in Norway.
Soft sandy bottoms, in depths from water's edge to 75 ft. Often found far inland in fresh water.
This is a right-eyed sole. Identifying characteristics are the lack of a pectoral fin.
Naked Sole is similar but scaleless.
I make no claim as to the accuracy, validity, or appropriateness of any information found in this website. I will not be responsible for the consequences of any action that is based upon information found here. Scuba diving is an adventure sport, and as always, you alone are responsible for your own safety and well being.
Copyright © 1996-2016 Rich Galiano
unless otherwise noted