The polyclads (Platyhelminthes: Polycladida) from the Tropical Eastern Pacific: Commented checklist and description of a new species Author Ramos-Sánchez, Mariela Doctorado en Ciencias Biológico Agropecuarias, Área Ciencias Biológico Agropecuaria y Pesquera, Ciudad de la cultura “ Amado Nervo ”, Tepic, Nayarit, 63000, Mexico. & Laboratorio de Sistemática de Invertebrados Marinos (LABSIM), Universidad del Mar, campus Puerto Ángel, Ciudad Universitaria, Puerto Ángel, Oaxaca, 70902, Mexico. text European Journal of Taxonomy 2024 2024-10-17 962 1 1 67 https://europeanjournaloftaxonomy.eu/index.php/ejt/article/download/2683/12419 journal article 10.5852/ejt.2024.962.2683 2118-9773 40171C5B-90EB-4641-91FF-EA8CA2C60D23 Boninia oaxaquensis Ramos-Sánchez, Bahia & Bastida-Zavala, 2020 Boninia oaxaquensis Ramos-Sánchez, Bahia & Bastida-Zavala, 2020: 51–56 , figs 2a–i, 3a–b, 4a–e ( type locality: Panteón Beach, Puerto Ángel, Oaxaca , Mexico ). Distribution Central coast of Oaxaca : Agua Blanca, San Agustinillo, Panteón, Estacahuite Beaches and Cacaluta Bay. This is the first record of the genus for the Tropical Eastern Pacific. Habitat Benthic, littoral to sublittoral ( 2–10 m ). Specimens of Boninia were collected under rocks, frequently in tide pools, in groups of three to six specimens on each rock and alongside chitons and seaweeds. Remarks Boninia oaxaquensis is assigned to the genus Boninia based on prostatoid organs symmetrically surrounding the male gonopore. Boninia oaxaquensis presents 14–66 (n = 24, μ = 36, SD = 26) cerebral eyes and 36–126 (n = 24, μ = 78, SD = 45) marginal eyes, has between 16–24 (n = 24) prostatoid organs arranged in one girdle, and its habitat is in the littoral to sublittoral zone ( 2–10 m ), under rocks in tide pools and sublittoral rocks. Currently, the genus comprises seven valid species B. antillarum ( Hyman 1955c ) , B. divae Marcus & Marcus, 1968 , B. mirabilis Bock, 1923 , B. neotethydis Curini-Galletti & Campus, 2007 , B. oaxaquensis , B. uru Tsuyuki, Oya & Kajihara 2022 , and B. yambarensis Tsuyuki, Oya & Kajihara 2022 . Authors such as Bock (1923) , Hyman (1955a) , Marcus & Marcus (1968) , Curini-Galletti & Campus (2007) , and Ramos-Sánchez et al. (2020) have suggested that the key diagnostic characters for defining species within the genus are: the number of prostatoid organs, the arrangement and number of their girdles, which are distributed on each side of the penis papillae, the distribution and number of cerebral eyes and marginal eyes, and the habitat.