Maryland Fish Facts

Summer Flounder

Summer Flounder

Paralichthys dentatus

(A.K.A. - Fluke)

Key Distinguishing Markings:

This left-eyed flatfish has both eyes on the left side of its body when viewed from above with the dorsal, or top fin, up.
The "eyed" side of this fish is scattered with 10 to 14 eye-like spots which blend in with the ocean floor.
Its belly or underside is white.

View the Summer Flounder Gallery

Distribution:

Summer flounder are found in estuarine and coastal waters from Nova Scotia to Florida.
They are most abundant from Cape Cod, Massachusetts to Cape Fear, North Carolina.
Within Chesapeake Bay, summer flounder are largely restricted to waters south of Annapolis, but they can be found occasionally in the upper Bay.
These fish inhabit coastal and estuarine waters from spring to fall and move offshore to depths of 100 to 600 feet during the winter.
Their migration is presumably brought on by decreasing water temperatures and declining photoperiods in the fall.

Size:

Habitat:

Summer flounder spend most of their lives on or close to the bottom, as other flatfishes do.
Flounder use their flattened shape and ability to change coloration and pattern on the eyed side of their bodies to partially burrow in the sediment, lie in ambush and wait for their prey.

Spawning:

Spawning begins at about age 2 when the fish are approximately 12 inches in length and generally occurs in the fall and winter during offshore migrations and/or at the wintering grounds.
Winter spawning migrations in Chesapeake Bay occur in October.
Fish begin to move south nearshore along the beach from October to December.
Fish spawning north of Chesapeake Bay begin in September and continue through December, while fish spawning south of Chesapeake Bay begin in November and end in February.
Larvae drift and migrate inshore, entering coastal and estuarine nursery areas between October and May. These larvae more closely resemble the larvae of other fishes than adult flounder, with body symmetry and eyes on both sides of their head.
Upon reaching the estuaries, larval flounder undergo metamorphosis and their eyes gradually migrate to the left side of the head and the body takes on a flattened appearance.
These post-larval fish then become bottom-dwelling and spend their first year in eelgrass beds of bays or inshore areas.
At the end of their first year, juveniles in the Chesapeake Bay region and the coastal bays join the offshore migration of adult fish.

Fishing Tips:

Summer flounder are a highly prized fish sought by both commercial and recreational fishermen throughout Maryland.
Summer flounder are a popular target of fishermen in the Maryland coastal bays.
The most popular baits are minnows and squid strips, and drifting is the most popular method of fishing.
The recreational fishery for summer flounder in the Maryland portion of the Chesapeake Bay occurs in late summer from the Bay Bridge south, with the greatest amount of effort closer to the Virginia line and the mouth of the Potomac River.
Summer flounder are occasionally but rarely targeted by anglers in the bay, and are more often caught along with a mixed bag by bottom fishermen on private and party boats.
For current recreational and commercial size and creel limits, see Maryland's updated regulation page.

Fun Fact:

The largest summer flounder ever caught measured 4 feet and weighed 30 pounds.
The oldest summer flounder ever recorded was aged at 20 years.
In Maryland's portion of Chesapeake Bay, the record summer flounder weighed 15 pounds and was taken at Buoy #50.

Family: Paralichthyidae (Large-tooth flounders)

Order: Pleuronectiformes (flatfishes)

Class: Actinopterygii (ray-finned fishes)

For more information on summer flounder and their management, please contact Steve Doctor.

Illustration Courtesy of Duane Rivers, USFWS

Maryland Department of Natural Resources