Review of the Chrysiptera oxycephala complex of damselfishes (Pomacentridae) with descriptions of three new species from the East Indian Archipelago

The nominal species Chrysiptera oxycephala has been considered a widespread species in the East Indian Archipelago, but genetic analyses and a closer examination of populations throughout the region now show it to be another example of a species complex of closely related parapatric cryptic species and genovariant populations. Three DNA lineages correlate with different color patterns and are described here as new species, including Chrysiptera ellenae (Raja Ampat, West Papua, Indonesia), Chrysiptera maurineae (Cenderawasih Bay, West Papua, Indonesia), and Chrysiptera papuensis(northeastern Papua New Guinea). The original C. oxycephala has the widest distribution, including central Indonesia, Sabah, Philippines, and Palau, as well as a local population in Sulawesi with a divergent mtDNA lineage, but no apparent phenotypic difference (Lembeh genovariant). An additional previously described species, C. sinclairi, is restricted to oceanic insular areas of northeastern Papua New Guinea. The five members of the species complex share most meristic and morphometric features, although some differences are evident in the modes and range of fin-ray counts and the number of scales (combined) on the preorbital and suborbital bones. Nevertheless, color patterns, especially those of small juveniles, distinguish five species, i.e. small juveniles entirely light blue (not persisting into adulthood) in C. ellenae; blue with a dark streak on each scale (and pattern persisting into adulthood) inC. sinclairi; light blue anterodorsally and yellow posteroventrally with a blue streak on upper caudal peduncle in C. maurineae; and light blue anterodorsally and yellow posteroventrally but no blue streak on upper edge of caudal peduncle in C. papuensis and C. oxycephala, but the former has the bicolor pattern with a bright yellow tail persisting into adulthood. The geographic distribution corresponds directly with color-pattern differences and mitochondrial-DNA lineages. The divergence in the control-region mtDNA sequence between the five species in the complex ranges from 2.9–10.9%, with the closest relationship between the species pair of C. maurineae and C. sinclairi, who nevertheless have very different color patterns and also differ in meristics. The two mtDNA lineages within C. oxycephaladiverge by 3%, greater than the difference between C. maurineae and C. sinclairi. These results indicate that genotypic divergence does not necessarily correlate well with phenotypic divergence within cryptic-species complexes of reef fishes