Peruvian nudibranchs (Mollusca, Gastropoda, Heterobranchia): an updated literature review-based list of species.

Nudibranchs, as a group, have received limited attention in terms of scientific study along the coastline of Peru. Here, an updated and comprehensive list of nudibranch species found in the Peruvian sea is presented, compiled through an extensive review of relevant literature. This compilation encompasses a total of 31 species, classified into two suborders, 10 superfamilies, 20 families, and 28 genera. With respect to the biogeographic provinces along the Peruvian coast, 23 species inhabit the Warm Temperate Southeastern Pacific province, 18 species occur in the Tropical Eastern Pacific province, and 10 species are found in both provinces, crossing the transitional zone between them. In terms of distribution patterns, two species exhibit a cosmopolitan distribution ( and ), while two species display a circumtropical distribution ( and ). One species exhibits a bipolar distribution in the Eastern Pacific and possesses an amphi-South American distribution (). Additionally, six species exhibit an amphi-South American distribution (, , , , , and ), and two species are endemic to Peru ( and ). This study provides comprehensive information on biogeographical aspects, geographical distributions, and taxonomic updates within the nudibranch species documented in Peru. Furthermore, we discuss the status of species listed in previous literature that have not been confirmed by collections, referring to them as potentially occurring species.