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fish), the pattern includes an extended winter period that lasts from November through <br />April. During this time, razorback suckers were primarily located in pools (61%) and slow <br />runs (24%) and were occasionally found in low-velocity eddies (11%) associated with <br />pools. <br />Spring <br />In April or May razorback suckers begin to move in search of spawning sites. Use <br />of pools dropped off entirely during May while use of slow runs (36%) and backwaters <br />(45%) increased. Flooded gravel pits become available during June and razorback suckers <br />tend to seek out these sites for staging or spawning activities. Gravel pit ponds accounted <br />for 43% of June observations. <br />Summer <br />There is no clear distinction between spring and summer periods for razorback <br />sucker. July is a transitional month between the spring spawning period (late April through <br />late June) and the late summer growing season (August through October). As seasonal <br />flows decrease in July, flooded gravel pits become increasingly unavailable while <br />backwaters, formed at the base of de-watered side channels, appear. Radio-telemetered <br />razorbacks were located in such backwaters 36% of the time during July. Their use of <br />pools and slow runs also increased during July. Along with the spring months of May and <br />June, July was the only period that razorback suckers were sometimes found inhabiting <br />shoreline habitat (7-9% of observations). During August-October, pools and slow runs <br />were used almost exclusively, with the two habitats receiving approximately equal usage. <br />Other Life History Attributes <br />Reproduction <br />The timing of razorback sucker spawning appears to be related to a suite of <br />environmental variables that vary substantially among basin locations and among years <br />within locations. Spawning occurs earlier in the lower basin than in the upper basin. In <br />? <br />8