Microgadus tomcod Walbaum, 1792, Artedi.
OTHER COMMON NAMES
Three separate dorsal fins, two separate anal fins. Dorsal and anal fins separated by gaps and rounded in outline. Chin barbel present. Pelvic fins with one elongate ray. Caudal fin rounded. Olive brown to green dorsally, paler ventrally, with darker mottling on sides.
Once reported to occur along the coast of North America from Labrador to North Carolina, the tomcod now occurs only as far south as the Hudson River in New York, where it is common.
The tomcod is a coastal fish, ascending rivers into habitats with very low salinities, and living near or on the bottom. It is strictly riverine in the Hudson River, but also can survive landlocked in lakes. Young stages are found in estuaries throughout its range, but not those with limited (or no) freshwater input.
No migrations to offshore waters, but tomcod prefer colder temperatures and move into deeper waters during summer, returning to shallow waters during fall and winter.
FEEDING ECOLOGY AND DIET
Feeds mostly on small crustaceans (especially shrimps and amphipods), worms, small molluscs, squid, and very young fishes.
Tomcod spawning is accomplished during winter, and involves elaborate courtship
of small groups. Most egg deposition occurs well upstream, in the lowest salinities available, and eggs are weakly adhesive. In the Hudson River, 93–99% of spawners are young-of-the-year fish approaching their first birthday. Larvae hatch at 0.2–0.24 in (5–6 mm) total length and grow rapidly during their first spring. Growth is then depressed during summer and resumes in the fall.
SIGNIFICANCE TO HUMANS
Tomcod is a popular sport and food fish, mostly in Canada and New England states. In addition to a limited hook and line fishery, tomcod are taken with bag nets, pocket nets, and weirs.
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