An unexpected pattern of molecular divergence within the blue penguin (Eudyptula minor) complex

Abstract

The blue penguins (genus Eudyptula) have been subjected to extensive taxonomic revision. In 1976, the genus was reduced from 2 species to a single species (Eudyptula minor) with 6 subspecies, based on a morphometric analysis. Despite the later proposed rejection of the differentiation of subspecies in Eudyptula minor, following analysis of allozymes in some populations, the 6 subspecies have continued to be recognised in some popular and scientific literature. We compared the sequences of 3 mitochondrial gene regions (small ribosomal subunit, cytochrome oxidase b and the control region) from the 6 hypothesised subspecies to examine relationships within Eudyptula. We found evidence for 2 unexpected clades: the 1st consisting of Otago and Australian populations, the 2nd consisting of northern, Cook Strait, Chatham Island, and Banks Peninsula populations. Some support for these 2 clades was also found from a re-analysis of morphometric data and from a preliminary examination of vocalisations.