Range expansion of the invasive hydroid, Cordylophora caspia (Pallas, 1771), in Colorado River reservoirs.

Cordylophora caspia (Pallas, 1771) colonies have significant biofouling potential at hydropower facilities, which can increase maintenance and cause system failure. In 2015, C. caspia colonies were observed at dams along the Lower Colorado River system in Lake Powell UT, Lake Mead NV/AZ, Lake Mohave AZ/NV, and Lake Havasu AZ/CA. The hydroid was serendipitously found on settlement plates deployed for invasive dreissenid mussel monitoring. Species identification was confirmed by taxonomy and molecular analysis, and phylogenetic reconstruction was performed to identify the relationship of sequenced COI fragments relative to those from C. caspia specimens collected at other geographic locations. [ABSTRACT FROM AUTHOR]