Larval stages of the lake chub, Couesius plumbeus

Three collections of Couesius plumbeus eggs were laboratory reared. Larvae were described with emphasis on external morphology. They were characterized by (1) 25 to 30 preanal myomeres, (2) a diagonal row of melanophores across the surface of the breast, and (3) a concentration of melanophores on the distal hypaxial portion of the caudal peduncle. Larval characteristics were compared with those of its breeding associate Rhinichthys cataractae and other sympatic cyprinids which have similarly high preanal myomere counts.