The Hippasterinae is a subfamily within the Goniasteridae, consisting of five genera and 26 species, which occur in cold-water settings ranging from subtidal to abyssal depths. All known genera were included in a cladistic analysis resulting in two most parsimonious trees, supporting the Hippasterinae as monophyletic. Our review supports
Sthenaster emmae gen. et sp. nov. as a new genus and species from the tropical Atlantic and two new
Evoplosoma species,
Evoplosoma claguei sp. nov. and
Evoplosoma voratus sp. nov. from seamounts in the North Pacific.
Hippasteria caribaea is reassigned to the genus
Gilbertaster, which previously contained a single Pacific species. Our analysis supports
Evoplosoma as a derived deep water lineage relative to its continental-shelf,shallow water sister taxa. The genus
Hippasteria contains approximately 15 widely distributed, but similar-looking species, which occur in the northern and southern hemispheres. Except for
Gilbertaster, at least one species in each genus has been observed or is inferred to prey on deep-sea corals, suggesting that this lineage is important to the conservation of deep-sea coral habitats. The Hippasterinae shares several morphological similarities with
Circeaster and
Calliaster, suggesting that they may be related.
