Fishes of Canada's National Capital Region

Species Accounts

Hiodontidae - Mooneyes - Laquaiches

The Mooneyes are found only in North American fresh waters in central Atlantic, Arctic and Gulf of Mexico drainages. There are only 2 species, both found in Canada, with 1 in the NCR.

These moderate-sized fishes are similar in appearance to Herrings but have teeth on the tongue, roof of the mouth and jaws, and a dorsal fin far back over the elongate anal fin. There are 7 pelvic fin rays, a pelvic axillary process, 7-10 branchiostegal rays, a subopercular bone is present on the side of the head and scales in the lateral line number 51-62. There is a ventral keel to the body but no scutes as in herrings. Scales are cycloid. The swimbladder is connected to the skull. The eyes are large and far forward on the head near the rounded snout. There are adipose eyelids. There is a single pyloric caecum.

A unique feature is that eggs are ovulated directly into the body cavity and not carried externally via oviducts as in most bony fishes.

Mooneye / Laquaiche argentée
Hiodon tergisus Le Sueur, 1818

Taxonomy

Other common names include Toothed Herring, River Whitefish, Freshwater Herring, Cisco and White Shad. Locally called whitefish (Hopkins, 2000).

Key Characters

This species is the only member of its family in the NCR and is characterised by having a fleshy ventral keel from the pelvic to the anal fins, a dorsal fin origin in front of the anal fin origin, a long anal fin, a pelvic axillary process, no adipose fin, teeth in the jaws, and the mouth extending at most to mid-pupil level.

Description

Colour

Colour is olive to brown on the back with a steel-blue sheen, flanks are silvery and the belly white. Fins are dusky, and a black stripe margins the leading edge of the pectoral fin. Spawning males and females have a pinkish hue on their fins and bellies. The eyes are golden above and silvery below.

Size

Reaches 47.0 cm and 1.1 kg. A Bay of Quinte, Ontario fish weighed 0.65 kg and is the Canadian fishing record.

Distribution

Found from the James Bay lowlands of northeastern Ontario and adjacent Québec, south through the Ottawa River basin to the upper St. Lawrence and Lake Champlain, and lakes Ontario and Erie. Also in Lake of the Woods, southern Manitoba and Saskatchewan and the North and South Saskatchewan, Battle and Red Deer rivers of Alberta. In central U.S.A. south to the Gulf coast. In the NCR long known only from the Ottawa River but now recorded from the South Nation River at Casselman (29 May 2004).

Origin

This species entered the NCR from a Mississippian refugium.

Habitat

Mooneyes are found in both running and still shallow waters of lakes and rivers and appear to be sensitive to turbidity. They are usually taken at less than 11 m depth. Their preferred temperatures are 22-27°C. There is a migration up rivers to spawn in the spring.

Age and Growth

Males mature as early as 3 years while females are mature at 4-5 years, generally. Talajic (1980) studied this species in the Ottawa River above and below Ottawa. Life span is up to 13 years in the Ottawa River using scales for ageing verified by reading otoliths and vertebrae. Females live longer than males, the latter reaching 11 years in the Ottawa. Females mature at age 4 above and below Ottawa while males mature at 3 years (below Ottawa) and 4 years (above Ottawa). Females outnumber males by 2.2:1 (below Ottawa) and 3.4:1 (above Ottawa). Males and females showed no significant differences in length, weight and age although fish below Ottawa were significantly smaller than fish above Ottawa at an age. Growth is similar to other mooneye populations in Canada.

Food

Food includes insects, crustaceans such as crayfish and plankton, molluscs and small fishes. Ottawa River Mooneyes fed on ants, mayflies, dragonflies and beetles based on stomach contents (McAllister and Coad, 1975). Talajic (1980) found that the most important foods in the Ottawa River were Ephemeroptera, Trichoptera, Diptera and Coleoptera with smaller amounts of other aquatic insect larvae and, rarely, minnows, clams, spiders and crustaceans. Flying ants were also found in large numbers. Food depended on availability, varying through the year. Feeding often occurs at the surface in the evening and during the night when insects fallen on the water surface are taken aided by the light-sensitive eyes.

Reproduction

Spawning takes place in April-June and each female may produce up to 20,000 buoyant, blue-grey eggs of 2.1 mm diameter deposited over rocks and gravel in running water. Ripe females have been caught at the beginning of June near the mouth of the Gatineau River (McAllister and Coad, 1975) and Talajic (1974) found spawning from mid-May to mid-June at 10-14ºC. Talajic (1974) recorded up to an average of 9000 eggs of average diameter 2.24 mm, with the largest eggs to 2.98 mm.

Importance

This species is of limited commercial importance, mostly on the U.S. side of Lake Erie. Various Herrings and Whitefishes have been listed erroneously as Mooneye in catch statistics. Commercial fisheries for mooneyes above and below Hull from the Québec side of the Ottawa River is documented by Pluritec (1982b), assuming "Laquaiche aux yeux d'or" is a mis-nomer for this species. Ontario Ministry of Natural Resources (OMNR) and Gouvernement du Québec Faune et Parcs (1999) report one license is issued for this species in the Ottawa River (Carillon to Ottawa-Hull). It is caught by anglers who specialise in catching this unusual sport species using flies, worms, grasshoppers, minnows or lures on light tackle. It is best eaten spiced, smoked or fried with butter and onions as it is dry and tasteless when fresh

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© Brian W. Coad (www.briancoad.com)