Mitochondrial DNA analysis of round goby (Neogobius melanostomus) and tubenose goby (Proterorhinus marmoratus) in the Great Lakes basin

Among the most recent introductions of exotic species into the Laurentian Great Lakes were the round goby and tubenose goby, which have appeared within the last 10 years. The source(s) of these gobies may be from natural populations in the Black, Azov, or Caspian seas. We used the mitochondrial cytochrome b gene to examine several aspects of the invading goby population: (i) to begin characterizing genetic diversity in the invading population; (ii) to investigate a possible source population using round gobies from the Black Sea; and (iii) to use sequence data to examine phylogenetic relationships within the Gobiidae, for which no sequences had previously been determined, and to compare these sequences with those from other fish. Five round goby haplotypes and one tubenose goby haplotype were identified. Round goby haplotype frequencies suggest that the population in the Great Lakes basin does not originate from a site sampled in the Black Sea near Varna, Bulgaria. Comparisons of the cytochrome b sequences of round goby, tubenose goby, and other previously sequenced fish gave the expected phylogenetic relationships.