Spot (Leiostomus xanthurus) belongs to the family of fishes called Sciaenidae. Spot plays a key role in the trophic dynamics of the Chesapeake Bay, as a predator of benthic invertebrates and as a prey species for striped bass, bluefish, weakfish, shark and flounder. Like croaker, spot are opportunistic bottom feeders that consume polychaetes, crustaceans and mollusks, as well as plant and animal detritus. Although both spot and croaker have similar diet and habitat, they are able to coexist without directly competing with one another.
Mature spot are easy to recognize by their physical characteristics: they have a relatively deep, short, compressed body; a short head with a small, mouth; and a large, black shoulder spot. Other distinguishing characteristics include an absence of teeth from the lower jaw, a long pectoral fin extending beyond the tip of the pelvic fin, and a strongly notched but continuous dorsal fin.
Spot swim in coastal and estuarine waters from the Gulf of Maine to the Bay of Campeche, Mexico. The area of greatest abundance occurs from the Chesapeake Bay to South Carolina. They have been collected from the mainstem and all tributaries of the Chesapeake Bay and have one of the most extensive distributions of any marine-estuarine fish species in the Bay. They are tolerant of a wide range of temperatures and have been collected in waters from 34-98 degrees.
Life Cycle
* Adult spot migrate into estuarine areas in the spring but are not as widely distributed as juvenile spot. They are generally found in the Chesapeake Bay from April through October.
* They are relatively short-lived; it is rare to find a f5 year-old. Ages 0 to 2 dominate the catch from populations along the Atlantic coast. Spot reach sexual maturity at ages two and three. Minimum size at maturity ranges from 186 to 214 millimeters.
* When the water temperature starts to decrease in the fall, adult spot move offshore to spawn. The spawning season extends from late fall to early spring. Spawning occurs over a broad area, and data indicate that they use deeper areas further offshore than other sciaenids.
* Fertilization is external, occurring at night in surface waters. Larvae grow rapidly in the warm offshore waters, but growth slows as they move into the cooler inshore and estuarine areas. This movement into colder water is a critical point in spot year class success, due to thermal stress at temperatures less than 10 degrees.
* Low salinity areas of bays and tidal creeks comprise the primary nursery habitat for spot. They are also associated with eelgrass communities.
* Young-of-the-year spot generally reside in tidal creeks and shallow, estuarine areas during the summer. When the water temperature begins to decrease in the fall they move to deeper estuarine waters or the ocean. There is some evidence that juvenile spot overwinter in the Chesapeake Bay in deep water. They are similar to adults in their ability to tolerate a wide range of salinities and temperatures.
The Fishery
Commercial landings for spot exhibit year-to-year fluctuations, which are attributed to the fish’s life history of spot and annual environmental differences on the spawning grounds. There are no apparent long-term trends. Within the Chesapeake Bay, the commercial harvest of spot usually begins during April or May and continues until September or October. The largest commercial catches are reported during fall when spot are migrating out of the Bay, and most spot are landed as bycatch from the pound net fishery in the lower Bay. In Maryland, commercial catches have ranged from 590,000 pounds in the 1950s to less than 100,000 pounds by 1990. Landings in Virginia have historically been higher than those in Maryland, ranging from 8 million pounds in the 1950s to approximately 150,000 pounds by 1990.
In Maryland, spot are one of the species most frequently caught by recreational fisherman. Spot ranked third in a 1980 recreational fishing survey with an estimated catch of more than 1.3 million fish. In Virginia, spot are generally larger, more abundant, and targeted by recreational anglers. Scrap catch, bycatch and discard mortality significantly affect the spot population.
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