Iphione Kinberg, 1856 includes tropical marine scaleworm species which live in rocky bottoms, often on the undersurface of coral rubble or rocks, and superficially resemble chitons. The most widely distributed species known is Iphione ovata Kinberg, 1856, originally described from Hawaii and recorded from the Red Sea and Indian Ocean to Western Mexico in the Eastern Pacific. A similar species, I. spinosa Kinberg, 1858, was described from South Africa based on a single specimen, which differed from the Hawaiian I. ovata by its fewer and larger elytral macrotubercles. The examination of over 100 specimens of different size and from various localities has permitted us to clarify ontogenetic variability in I. ovata. Certain specimens studied from the Red Sea to Hawaii and Southeastern Polynesia were sequenced for cytochrome c oxidase I and genetic variation of I. ovata was confined to a single genetic lineage confirming the wide range of the species and lack of cryptic lineages. Based on the available evidence, we confirm the wide distribution of I. ovata along the Indian and Pacific Oceans and include as junior synonyms I. spinosa and I. reticulata Amoureux, Rullier & Fishelson, 1978, originally described from the Red Sea with one small juvenile. A key for identifying all Iphione species from Hawaii is included.
Morphology, elytra, macrotubercles, cytochrome c oxidase I, variability