The Tarndale bully revisited with molecular markers:: an ecophenotype of the common bully Gobiomorphus cotidianus (Pisces: Gobiidae)

Genetic differentiation among populations of the Tarndale bully and three other Gobiomorphus species was investigated with mitochondrial DNA sequence variation. Sequences from parts of the mitochondrial cytochrome b gene and control region were obtained for 70 bullies. Specimens of Tarndale bully, known from only five small tarns in the northern South Island of New Zealand, clustered with specimens of common bully from both North Island and South Island locations, and not upland or Cran's bullies. The molecular results are discussed in relation to the morphometric and meristic variation, and the origin of the Marlborough tarns. It is concluded that populations of bullies in the Marlborough tarns are a lake-locked ecophenotype of the common bully and not a phylogenetic species.