REPRODUCTIVE-BIOLOGY OF THE QUILLBACK, CARPIODES-CYPRINUS, IN A SMALL PRAIRIE RIVER

Quillback (Carpiodes cyprinus (Lesueur)) spawning migrations were monitored in 1984 and 1985 in the Ochre River, Manitoba. Quillback migrations were limited by both water temperature and discharge. Upstream spawning migrations began after water temperatures reached 5-degrees-C but only when discharges were high. Quillback migrated up to 32 km upstream from Dauphin Lake during periods of high discharge but only 2-3 km upstream if discharges were low. Quillback probably are annual spawners and spawned from mid-April to mid-June at water temperatures between 7 and 18-degrees-C. Fecundity ranged from 46 600 to 360 000 ova in females of 912-3410 g wet weight. Fecundity had a linear relationship to quillback wet weight. Relative gonad weight, ova diameter, and dry weight of ova all increased with increasing female weight. Fertilized ova hatched after 13-17 calendar days or 220.7-229.8 degree-days. The mean total length of newly hatched larvae was 7.95 mm. Tubercle distributions were similar to previously described patterns except that, in addition, Dauphin Lake quillback bore tubercles on the dorsal surface of the head, the anal and caudal fins, and the cornea of the eye.