White Sucker

Catostomus commersonni (Lacépede) The common white sucker has an elongated, cylindrical body with large, generally silvery, scales.

The snout is blunt and the inferior mouth has thick lips which have two or three rows of tubercles.

Coloration may be variable, but it is generally olivaceous, and darker at spawning time.

Breeding males have a black lateral band, a salmon-coloured or rosy Flush beneath the lateral band, and tubercles on the anal fin and the lower portion of the tail lin.

Young fish usually have three black spots on the sides of the body: one immediately behind the head, one below the dorsal lin, and one at the back of the caudal lin.

Distribution:
In northern Canada, the white sucker is distributed from the Mackenzie River, Hudson Bay and Labrador to the Maritime Provinces, and in the United States, southward on both sides of the Appalachians to Georgia, Arkansas and Colorado.

ln Ontario, it occurs in almost all lakes and rivers from the Great Lakes to Hudson Bay.

Habitat:
The white sucker spends most of its time on the bottom of clear, shallow water of small to large streams and lakes.

Habits:

Movements: After spawning, the adults return to quieter waters.

Postlarvae or immaturely developed fry soon follow and, in early spring.

Swarms of these may be found along the borders of the lake.

As transformation to the young lish stage takes place, they may move into shallow, shoreward vegetation.

In April or May, the white sucker ascends streams to spawn in moderate to swift riffles, in gravelly and stony areas, when the water temperature is above 40°F.

The spawning grounds may be similar and in close proximity to those used by the walleye, but the sucker spawns later and in shallower water.

Observations have also shown that spawning takes place in the shallow water of lakes.

Enormous numbers of eggs are scattered at random over the spawning grounds; it has been estimated that an adult female will lay 30,000 eggs.

The first food of the young sucker is plankton or minute, free-floating and free-swimming life in the water but, as a change in the structure of the mouth takes place, a bottom feeding habit is developed.

Bottom ooze is fed upon extensively during the early period of bottom feeding; the protrusible mouth is well adapted for sucking food off the bottom.

After a length of two inches is reached, insects begin to show in larger and larger numbers in the diet.

The sucker is principally insectivorous and, because of this, it competes with trout and bass, species of prime importance.

Other food items are aquatic plants, molluscs and worms.

Food is not normally taken during the spawning season.