Taxonomy and distribution of the Malheur mottled sculpin, Cottus bendirei

The taxonomy of mottled sculpins (Cottus bairdi complex) in Harney Basin, O regon was reviewed and diagnostic characters were evaluated. The literature and current data support recognition of two species, Malheur mottled sculp in (C. bendirei) and Columbia mottled sculpin (C. hubbsi). Counts of body p rickles on the left side, completeness of lateral line and relative head si ze were used to classify Harney Basin individuals. Both species occurred in northern Harney Basin and hybrids were found at contact zones in Silver an d Silvies rivers. Cottus hubbsi appeared dominant in mainstem Silvies R, wi th C. bendirei upstream and in isolated creeks. Cottus bendirei was the onl y species in southern Harney Basin. Both species also occurred outside Harn ey Basin in the Malheur and Snake rivers, lower Columbia Basin, and probabl y the upper Columbia Basin. An alternative hypothesis, that these forms rep resent a single polymorphic species or ecotype, was tentatively rejected be cause the congruence of morphology and distribution was consistent with two species meeting in a narrow hybrid zone. A better understanding of reprodu ction, development and the dynamics of sculpin hybrid contact zones is need ed to resolve the question.