7229

• UCREFRP Catalog Number: 7229
• Author: Kaeding, L. R. and M. A. Zimmerman
• Title: Life History and Ecology of the Humpback Chub in the Little Colorado and Colorado Rivers of the Grand Canyon
• USFW Year: 1983
• USFW - Doc Type: Transactions of the American Fisheries Society
• Copyright Material: NO

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he suggested that these habitats might be used if more desirable habitats were
not available. Therefore, it is assumed that white sucker adults select
moderate stream velocities for spawning.

The fert il i zed eggs adhere to the gravel in riffl es or drift downstream
where they adhere to the substrate in areas with water of slow velocity (Geen
et al. 1966). White sucker fry emerge about 9 to 11 days after hatching and
drift downstream at night.

Specific Habitat Requirements

White suckers tolerate a relatively broad range of environmental condi-
tions. Even though white suckers are generalists, optimum habitat conditions
for the species can be described.

Stream populations of white suckers reach maximum abundance in low to
moderate gradient streams (Stewart 1926). Minckley (1963) and Hocutt and
Stauffer (1975) reported white suckers in streams with an average gradient of
6 m/km; Hocutt and Stauffer (1975) collected 70 white suckers at gradients of
2.8 to 7.8 m/km, 28 suckers at gradients of 10 to 13.4 m/km, and only 5 suckers
at a gradient of 28.4 m/km. Curry (1979) observed white suckers spawning in
streams with gradients of 1.2 to 2.3 m/km.

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Adult white suckers (> 150 mm TL) primarily inhabit pools (Propst 1982b)
and are common in areas of slow to moderate velocity (approximately 40 cm/sec),
although smaller individuals (< 150 mm TL) occur in a greater variety of
habitats than adults (Stewart 1926; Scherer 1965; Pflieger 1975; Propst 1982b).

Stewart (1926) was unable to find white suckers in pools that were
entirely isolated from any inflow; Propst (1982b) supported the idea that
water movement was important because suckers were uncommon or absent at pothole
sites with no flow. Symons (1976) reported that white suckers appeared to
have trouble maintaining equilibrium in fast or turbulent water and that
suckers were sighted more often in artificial streams with slow runs at modal
velocities of 10 to 19 cm/sec. Propst (1982b) did not find white suckers in
pools with flows> 10 cm/sec and Minckley (1963) found white suckers in pools
with flows that were usually near 15 em/sec. Propst (1982b) reported that
substrates in pools inhabited by adult white suckers were a mixture of rubble,
gravel, and sand with a silt overburden.

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Propst (1982b) reported a high correlation between pool cover and white
sucker populations. Minckley (1963) observed that when aggregations of white
suckers in pools were disturbed they moved quickly into debris or other cover.
Cover, including both streamside cover and within-stream cover, is a very
important, if not essential, component of spawning areas for dwarf suckers, C.
c. utawana (Dence 1948). Thompson and Hunt (1930), Oence (1948), and Propst
(1982b) descri bed whi te sucker habi tats with exposed tree roots, numerous
drifts of brush and logs against fallen trees, bridge supports, riprapped and
undercut banks, and large boulders available as cover. Oence (1948) reported
that the dwarf sucker seeks out streams in shaded woods during breeding season.
Thompson and Hunt (1930) described white sucker habitat as commonly shaded by
trees on the bank or by overhanging grass, weeds, and shrubs.

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