Spotted seatrout are found in coastal waters of the western Atlantic Ocean from Massachusetts to Florida and throughout the entire Gulf of Mexico. They’re most common along the northern Gulf and Florida Gulf Coast.
Spotted seatrout live in the brackish waters of upper estuaries out to waters about 30 feet deep in the Gulf. Adults often spend their whole lives in or near the estuary where they were born. They swim near seagrass beds, oyster reefs, and other shallow water habitats, mostly in the lower parts of estuaries, and in the open Gulf of Mexico during spring and summer to feed and spawn. When waters cool in the fall, they move into deeper waters and scatter throughout the estuaries. They return to shallower, saltier waters in the spring as waters warm.
Spotted seatrout grow fast and are able to reproduce by the age of one or two. Females grow more quickly and reach larger sizes than males—females are about 11 inches when they sexually mature, males are much smaller. Females also live longer, up to 10 or 12 years; males rarely live longer than five years (so most spotted seatrout in a population older than five are likely females). On average, spotted seatrout weigh two to three pounds. Males on average grow to 19 inches in length by the end of their life; females average 25 inches by the end of their life.
From March to October, hundreds of thousands of male spotted seatrout gather in shallow, saltier areas of coastal bays, estuaries, and lagoons, especially near passes or other areas with currents, to spawn. Males use specialized muscles along their swim bladder to make a drumming sound to attract females. Females release their eggs; males then fertilize the eggs by broadcasting sperm over them. Spotted seatrout are very productive—they can spawn multiple times per season, and females (depending on their size and age) can release millions of eggs per year. Eggs hatch in about 18 hours, and the young trout find shelter in shallow marsh ponds and along marsh edges to avoid predators.
Larvae float in the water column and feed on plankton; young trout feed on small crustaceans and fish. Adults often school together and move into shallower areas to feed on fish with the incoming tide. They eat many species of fish and shellfish. One of their favorites is mullet—they can eat one more than half their size. Larger fish including gar, striped bass, tarpon, and barracuda, feed on spotted seatrout; other predators include dolphins, sharks, and birds.
Spotted seatrout have iridescent, dark gray or greenish upper sides and back and are white on their lower sides and belly. Their dorsal fin is long and separated by a deep notch. Their dorsal fin and tail are dusky, their tail’s edge is black, and their other fins are pale or yellowish. They look similar to other related species (such as sand and silver seatrout) but can be distinguished by the round dark spots on their back, fins, and tail. They have a streamlined body and a long pointed head; their lower jaw extends farther than their upper jaw. They have two large canine teeth at the front of their upper jaw (which sometimes break off during their life), and the edges and inside of their mouth are often yellow.