Department of Environmental Conservation

D E C banner


Hiodon tergisus

New York Status: Threatened



The mooneye is a medium-sized fish, usually reaching 11-15 inches in length and 1-2 pounds in weight. It has a flattened slab-sided body that is silvery in color. It has several distinguishing characteristics including: large, prominent eyes; a short snout; smooth, rather than saw-edged, scales on the belly; and a small flap (called a pelvic axillary process) located just above the pelvic fin. In addition, the mooneye has teeth on the tongue and on the middle of the roof of the mouth.

Life History

A spring spawner, the mooneye migrates into medium to large-sized rivers from March through May to deposit its eggs. Adults deposit the eggs over rocks in swift water areas.

The eggs are covered in a gelatinous material similar to frog's eggs. Female mooneye release approximately 10,000-20,000 eggs.

By the end of the first year, a mooneye grows to be four inches in length. In Lake Champlain, the mooneye reaches 12 inches in length by age eight.

The mooneye eats a wide variety of organisms including insects, crustaceans, small fish, and mollusks.

Distribution and Habitat

The mooneye is found in waters from south-central Canada (Hudson Bay Basin) south though the Great Lakes Basin (except Lake Superior), the St. Lawrence River, and the Lake Champlain drainage basin. While the mooneye is thought to be extirpated from New York portions of Lakes Ontario, there remains a modest population in of this fish in Lake Champlain. There are also remnant populations in Black Lake, the Oswegatchie River, Lake Erie, the mouth of Cattaraugus Creek and the St. Lawrence River. The Allegheny River contained this fish before 1900. The mooneye prefers clear water habitat of large streams, rivers, and lakes.

Population Status

Mooneye populations are decreasing both in numbers and in locations where they are found. While the exact causes of population declines are not known, it is due in part to increased siltation occurring in clear water areas where mooneye normally occur.

Management/Research Needs

DEC will continue to protect the mooneye from harvest. In addition, DEC will protect critical mooneye habitat as it becomes identified.

  • PDF Help
  • For help with PDFs on this page, please call 518-402-8924.
  • Contact for this Page
    Bureau of Fisheries
    625 Broadway
    Albany, NY 12233-4753
    Send us an email
  • This Page Covers
  • Page applies to all NYS regions