All About Spotted Seatrout

spotted_trout_cropSpotted seatrout are a sought after fish species for both recreational and commercial fishermen in Florida. They are distributed along the Atlantic and Gulf Coasts from Cape Cod, Massachusetts to southern Florida and throughout the Gulf of Mexico to Carmen Island in the Lower Gulf of Campeche, Mexico. They are most common along the Gulf coast from the west coast of Florida to Texas.

Spotted seatrout are unique in that that their entire life is estuary dependent and they rarely migrate far from the estuaries where they were spawned. They can tolerate wide salinities and may be found in waters ranging from fresh to hyper saline.

In southwest Florida, spotted seatrout are generally found associated with vegetated areas, such as seagrass beds and mangroves, and in close proximity to deep areas for seeking refuge from extreme temperatures. In the northern Gulf where seagrass is sparse, spotted seatrout are found in and adjacent to marshes, over sand, mud, shell reefs, and around oil platforms.

During their adult life, these beautiful fish have elongated silvery bodies with a slightly elevated back, and yellow-green dorsal and caudal (tail) fins. They have a pointed snout, and a large mouth lined with many sharp teeth, and two distinct canine teeth on their upper jaw that aid in feeding. True to their name, spotted seatrout have irregular black spots on their upper half, which extend from their first dorsal fin through their caudal fin.

Untrue to their name, spotted seatrout are not really trout. True trout are members of the family Salmonidae, which includes salmon, trout, and char. Spotted seatrout are members of the family Sciaenidae (sigh-EE-nih-dee) which includes redfish, croaker, and black drum.

Sciaenids are known for having the ability to produce a “croaking” or “drumming” sound by vibrating special red sonic muscles against their swim bladder. Both male and female sciaenids “drum” during courtship and spawning; however, spotted seatrout are unique in that sound production is exclusive to males. Female spotted seatrout do possess the red sonic muscles but do not appear to use them for sound production.

Spotted seatrout males become sexually mature around age two when they are about 8-9 inches long, and females mature at three years when they are 8-10 inches long. Spawning along the western Gulf takes place from late March to September with peak spawning from June through August. Spawning occurs over seagrass, and within or near channels and passes.

Spawning events usually begin around sunset when male spotted seatrout “drum” to communicate the location of the spawning site. Once males and females are aggregated together, both eggs and sperm are released into the water column and the fertilized eggs are left to drift with the current. Spawning lasts around three or four hours, with residual spawning lasting up to six hours.

Spotted seatrout are batch spawners, meaning they will disperse several packets of eggs over the course of a season. The number of times a female spawns and the number of eggs she produces increases with her size. On average a female will produce 15,000 to 1,100,000 eggs each spawning event.

Spotted seatrout eggs hatch after 18 hours and larvae immediately seek out bottom vegetation or shell rubble. Nine to eleven days after hatching, spotted seatrout larvae develop teeth. At this age the larvae are able to stalk prey by moving slowly to within a body length and then lunging to capture their prey. At 6-8 weeks of age (1-2 inches in length), juvenile spotted seatrout begin to form schools and seek out habitat in which to reside.

Spotted seatrout live about 8-10 years and can grow to a maximum length of 39 inches. Adults are ambush predators, making quick lunges to grab prey with their front canine teeth prior to swallowing it whole. They feed more heavily in the early to midmorning, and their prey is primarily shrimp and small fish. When they do feed, they regurgitate portions of food, which floats to the surface creating the oil slick that anglers look for when fishing.

Spotted seatrout may be infected by a whole host of pathogens and parasites, but probably the most frequently encountered is the spaghetti worm—larval stage of the tapeworm Poecilancistrium caryophyllum. Infected fish appear to have long, thin worms tunneled in the flesh. The worms are harmless to humans, and also do not appear to cause harm to adult spotted seatrout.

Spotted seatrout is managed for both commercial and recreational fishing in Florida. Management is divided into four spotted seatrout zones (Northwest, Northeast, Southwest, and Southeast). Different commercial and recreational regulations apply to each zone based on how well a zone is doing in meeting the State’s management goal for this species. For more information about spotted seatrout management and regulations in Florida visit: http://myfwc.com/fishing/saltwater/.

Spotted seatrout are very delicate, so it’s important to return unwanted or illegal fish promptly to the water in order to ensure a healthy fish population. Recall, a big female can produce a million or more eggs each time she spawns, so releasing large spotted seatrout to breed can result in more little ones for the future.

Did you know? The scientific name for spotted seatrout is Cynoscion nebulosus which is derived from several Greek words. If we break down the genus name Cynoscion, Cyno means dog-like and scion means a sea-fish. The second, or species, name, nebulosus, means dark and clouded. So if you put that all together, spotted seatrout are dark, clouded dog-like sea-fish. The dog-like reference likely comes from their canine teeth.

 

Sources:

Blanchet, H, M Van Hoose, L McEachron, B Muller, J Warren, J Gill, T Waldrop, J Waller, C Adams, R Ditton, D Shively, and S VanderKooy. 2001. The spotted seatrout fisheries of the Gulf of Mexico, United States: A regional management plan. Gulf States Marine Fisheries Commission, Publication number 87.

Brown-Pterson, NJ, MS Person, DL Nieland, MD Murphy, RG Taylor, and JR Warren. 2002. Reproductive biology of female spotted seatrout, Cynoscion nebulosus, in the Gulf of Mexico: differences among estuaries? Environmental Biology of Fishes 63: 405-415.

Flaherty-Walia, KE, RE Matheson Jr. and R Paperno. 2015. Juvenile spotted seatrout (Cynoscion nebulosus) habitat use in an eastern Gulf of Mexico estuary: The effects of seagrass bed architecture, seagrass species composition, and varying degrees of freshwater influence. Estuaries and Coasts 38: 353-366.

Florida Museum of Natural History. 2016. Cynoscion nebulosus. https://www.flmnh.ufl.edu/fish/discover/species-profiles/cynoscion-nebulosus/

FWC. 2016. Spotted seatrout. http://myfwc.com/fishing/saltwater/recreational/spotted-seatrout/

Lowerre-Barbieri, SK, Walters, J Bickford, W Cooper, R Muller. 2013. Site fidelity and reproductive timing at a spotted seatrout spawning aggregation site: individual versus population scale behavior. Marine Ecology Progress Series Vol. 481: 181–197.

McMichael, RH and KM Peters. 1989. Early life history of spotted seatrout, Cynoscion nebulosus (Pisces: Sciaenidae), in Tampa Bay, Florida. Estuaries Vol. 12(2): 98-110.

Fish illustrations by Diane Peebles