Round Whitefish – Profile | Behavior | Lifecycle | Diet | Habitat

Round Whitefish

Round Whitefish, scientific name Prosopium cylindraceum is a member of the Salmonidae family, the round whitefish seldom exceeds 2 kilos and is sought to a restricted diploma by anglers.

Round Whitefish Distribution

The round whitefish happens in arctic drainages and is a wide-ranging species within the northern parts of North America. It has disjunct populations, considered one of which is discovered by the St. Lawrence-Great Lakes basin (aside from Lake Erie), north to the Arctic Ocean east of Hudson Bay.

The difference is discovered all through the northern Canadian provinces and Alaska west of Hudson Bay. It additionally happens in restricted areas straight south of Hudson Bay and in East Twin Lake in Connecticut.


The round whitefish is usually silvery and has a darkish brown to nearly bronze coloring, with a greenish tint on the back. It has black-edged scales, significantly on the back.

The decrease fins are amber shade, turning into barely more orange throughout spawning, and the adipose fin is often brown noticed. Young fish have two or more rows of black spots on the edges which will merge with a row of black spots on the back.

The round whitefish has a small head, a reasonably pointed snout, and a single flap of pores and skin between its nostrils. It additionally has a forked caudal fin, 74 to 108 scales down the lateral line, and 14 to 21-gill rakers.

The round and the lake whitefish might be simply distinguished from one another as a result of the round whitefish has a really cylindrical body, whereas the body of the lake whitefish is laterally compressed.

Round Whitefish Size

Usually about eight to 12 inches long and weighing 1⁄2 pound or much less, the round whitefish can develop to more than 20 inches long and weigh a number of pounds. The all-tackle world document is a 6-pounder taken in Manitoba in 1984.

Round Whitefish Description

Dorsal spines (complete): 0; Dorsal smooth rays (total): 11-15; Anal spines: 0; Anal smooth rays: 10 – 13. Body slender, elongate, nearly cylindrical in cross-section, posteriorly considerably compressed laterally, best depth in entrance of the dorsal fin.

Head comparatively brief; eye average, its diameter lower than snout size; snout pointed, “pinched” or compressed laterally, rounded in lateral view, a single flap of pores and skin current between the nostrils; mouth small, ventral in place, overhung by snout; maxillaries extending posteriorly nearly to anterior margin of the eye in adults. This species has more shade than most coregonids. The general coloration of adults nearly silvery, silvery-white beneath.

Scales particularly on the back, with well-defined, darkish pigmented borders, making them conspicuous. Pectoral fins are amber in shade, slight amber tint additionally to pelvic and anal fins.

Pectoral fins tackle an orange tint throughout spawning, the pelvic and anal fins additionally to a lesser extent. the adipose fin is often brown noticed, significantly in specimens from central and eastern Canada. Two or more longitudinal rows of black spots are current on the edges of the younger specimen.

Round Whitefish Life cycle

Round whitefish have common migrations to and from freshwater tributaries, the place spawning takes place. Spawning websites are layered with various-sized pebbles and are beneath shoreline currents, roughly 1-1.5 meters (m) deep.

Even at this depth, there’s an underwater present, with a velocity of 0.5–1.0 m/s (meters per second), that disperses among the deposited eggs downstream within the tributary system.

Fertilized eggs are 3.10–3.25 mm in diameter and are held in areas between rocks in addition to within the ice crystals of the slushy, tributary flooring. The sexual dimorphism is refined in round whitefish compared to different species within the salmon household.

Males develop outlined pearl organs alongside the aspect of their body and have altered coloration throughout spawning. Its pelvic, pectoral, and anal fins, in addition to its stomach, grow to be anyplace from yellow-orange to pink in shade.

Round-fish are fall spawners, laying their eggs between early October and late November when the water temperature is at or beneath 2.5 °C. The spawning migration begins in August, though the first maturation fish have a tendency to start out-migrating as early as June.

The round-fish expertise their first spawning usually at age seven. These species don’t spawn yearly, however, it’s common for first-year spawners to spawn the next year.

After sexually mature round-fish attain the tributary system, general progress slows down, and annual progress increments lower from 55–65 mm to 40–45 mm resulting from a lower in food consumption.

Round Whitefish

Round Whitefish Habitat

Round whitefish are present in chilly freshwaters of Arctic seas, post-glacial lakes, rivers, and brackish waters. The wide-ranging pilot fish inhabits the northern waters of North America to the northeastern waters of Asia, usually at a depth of 180 to 700+ feet.

In Asia, they generally inhabit the Siberian Yenisei River to the Kamchatka and the Bering Sea. The North American vary of the round-fish contains the Great Lakes (besides Lake Erie), areas of the Arctic Ocean, Hudson Bay, waterways in northern Canadian provinces, arctic brackish waters, and all through Alaska.

Although they’re freshwater species, the round-fish might be present in areas within the Arctic Ocean that have very low salinity, which happens from the abundance of rivers and waterways that vacant into the Arctic Sea. This explains their vast distribution in northern waters.

Round Whitefish Diet

Round whitefish are thought-about benthivores, feeding on benthos and plankton. In addition to the earlier checklist, the generalized feeding sample of the round-fish weight-reduction plan contains amphipods, gastropods, isopods, chironomid larvae and pupae, and numerous aquatic bugs, reminiscent of a spiny water flea (Bythotrephes longimarus).

Round whitefish are secure generalized feeders as a result of the majority of their meals being discovered within the deeper elements of the water.

They are thought-about opportunistic feeders in that round-fish feed on the sort of prey that’s accessible. Among completely different populations, the principle meals supply every group preys on might differ from each other in relation to what sort of meals is accessible.

Other components that affect meals availability are location, neighboring species, and time of year. In completely different bodies of water at completely different occasions of the year, the type and quantity of prey change, and round-fish are tailored to have the ability to feed on what’s seasonally accessible. This functionality permits them to emigrate periodically to and from spawning websites.

Food availability can also be influenced by the abundance of different species sharing and/or across the vary of the round-fish. When species return to their non-spawning body of water after spawning and winter, the round-fish weight-reduction plan consists of more chironomids, isopods, and gastropods.

During the migration to spawning websites, they largely feed on spiny water fleas, black fly larvae, and different aquatic bugs. These species don’t feed throughout spawning, so it is necessary for them to extend their meal consumption to build up energy for storage to outlive by spawning.

Spawning conduct

Spawning takes place through the fall in lakes, in tributary mouths, and infrequently in rivers over gravelly shallow areas. The fish spawn in pairs; their eggs hatch within the early spring.

Other Recommended Reading

Other Names

menominee, round fish, frost fish, pilot fish, grayback; French: ménomini rond.

Round Whitefish Fishing

Few anglers have caught and eaten menominee, however, those that do discover them glorious consuming. They are primarily an industrial species, much like lake whitefish however considerably smaller. Menominee is never seen besides after they enterprise into shallow (6-48 foot deep) waters in April and May and once more in October and November.

They are thought-about a shallow-water species within the Great Lakes however might vary out to depths as nice as 150 feet. Anglers might encounter menominee additionally inhabiting rivers. Learn more about giant gourami.

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