Dividing the monopoly: the most broadly distributed Actinopyga is two species (Holothuroidea: Holothuriidae)

Actinopyga mauritiana stands as one of the most renowned sea cucumbers due to its size, conspicuousness, abundance in intertidal to shallow subtidal waters, and wide distribution. It is documented to range from East Africa to Hawaii and Panama. It is also among the most sought-after species for the bêche-de-mer fishery. However, color, anatomical, and genetic data indicate that it is a complex of two species: the nominal form that ranges across the Indian Ocean, and Actinopyga varians, distributed across the Pacific. Both species live on the outer margin of exposed reefs and prefer oceanic conditions, evident by their abundance on small reefs and islands, and their absence or rarity in protected continental shores and reefs. Despite the substantial separation between the two forms, each shows strong genetic connectivity across its broad range. This paper formally separates the two taxa.