The arroyo chub (Gila orcuttii) is a cyprinid fish found only in the coastal streams of southern California, United States. The shape of the arroyo chub is somewhat chunky, with a deep body and thick caudal peduncle. The eyes are larger than average for cyprinids. Coloration ranges from silver to gray to olive green above, shading to white below, usually with a dull gray band along each side. The dorsal fin has 8 rays, while the rounded anal fin has 7. Males have larger fins than females, and, during the breeding season, patches of on the upper surfaces of the pectoral fins. This is a small fish, with most adults in the 7–10 cm length range, and a maximum of 12 cm.