9425 - Laserfiche WebLink

Home Browse Search

Reproduction. Roundtail chub spawn in spring and summer on the descending limb of the spring snowmelt hydrograph (Vanicek and Kramer 1969, Carlson et al. 1979, Karp and Tyus 1990b, Brooder et al. 2000, Brooder 2001). Vanicek and Kramer (1969), Vanicek et al. {1970), and Bestgen (19$5) concluded that water temperature was the most significant environmental factor associated with onset of spawning. Brooder (2001) found that spring flooding facilitated successful reprcxiuction and recruitment in the u Verde River. Spawning is associated with water temperatures ranging from 14 to PPS 24 °C, with 18 to 20 °C most commonly noted (Sigler and Miller 1963, Vanicek and Kramer 1969, Holden 1973, Constant 1981, Bestgen 1985, Kaeding et al. 1990, Karp and Tyus 1990b, Brooder et al. 2000). Spawning usually occurs over gravel in deep pools and runs (Neve .1976, Muth et al. 1985, Brooder et al. 2000), and eggs are adhesive and demersal (Sigler and Miller 1963, Constant 1981, Muth et al. 1985, Kaeding et al. 1990)• Neve (1976) and Brooder et al. (2000} observed several males attending each female in Fossil Creek and the Verde River, respectively. Average depth of spawning observed by Brooder et al. (2000) in the Verde River was 31.6 cm, and average current velocity was 43.8 cm/s. Usually, breeding females are slightly Larger than males (Neve 1976, Bestgen 1985, Muth et al. 1985, Karp and Tyus 1990b, Brooder et al. 2000). Roundtail chub typically mature between ages 3-5 at 150 to 300 mm in total length (Bestgen 1985, Sigler and Sigler 1996, Brooder et al. 2000). Average life span is probably 8-10 years or more in larger systems and less in smaller tributaries (Bestgen 1985, Sigler and Sigler 1996, Brooder et al. 2000). Fecundity varies with fish size. In spring-fed Fossil Creek, Arizona, Neve (1976) found female G. robusta ranging from 100 to 260 mm TL to contain between 1,000 and 4,300 mature eggs. Bestgen (1985) described reproducing females from Turkey Creek, New Mexico that were 2-4 years old,100-18I mm TL, and containing a total of 600-13,546 eggs greater than 3 mm in diameter. Ripe females collected from the larger East Fork of the Gila River averaged 4-7 years old or more, 299-368 mm TL, and contained 14,163- 45,124 eggs, suggesting that body size and reproductive strategies were likely different Final Report September 2002 21