Hardhead
(Mylopharodon conocephalus)

Mylopharadon conocephalus, known as the hardhead, is a freshwater ray-finned fish from the family Cyprinidae, the carps and minnows, which is endemic to California. It is the sole member of the monotypic genus Mylopharadon.

The hardhead has an elongated, slender body which is brown to dusky bronze above, the larger fish being darkest, with silver sides. The dorsal fin has its origin behind that of the pelvic fin, It has 69-81 scales on its lateral line; the dorsal fin has 8 rays. The jaws are not extendable and there is a premaxillary frenum. The snout is long and pointed, ending with the large, terminal mouth which reaches back to the front of the eye. It has 2.5-4.2 pharyngeal teeth.

It grows to around 30 centimetres (12 in) standard length.

The juvenile fish are silvery. The adult males grow small white nuptial tubercles on the head and on a band extending from the head to the caudal peduncle in the Spring spawning season.

The range of the hardhead includes much of the drainage basin of the Sacramento and San Joaquin in California, and within the range it is widely distributed in the foothill streams. The Kern River, Kern County, is the southernmost part of the range and it reaches north to the Pit River drainage in Modoc County.

It is absent from the Clear Lake basin and from most of the streams draining into San Francisco Bay, other than the Napa River and Russian River, where it is not common.