Pericelis ernesti Hyman, 1953

Ramos-Sánchez, Mariela, 2024, The polyclads (Platyhelminthes: Polycladida) from the Tropical Eastern Pacific: Commented checklist and description of a new species, European Journal of Taxonomy 962 (1), pp. 1-67 : 39-40

Pericelis ernesti Hyman, 1953

Marcusia ernesti Hyman, 1953a: 296–298 , figs 32–33 (type locality: Gulf of California, Mexico).

Pericelis ernesti – Hyman 1955d: 263 (new combination). — Soutullo et al. 2021: 373, fig. 6b–e (new record from Playa Carbón Beach, in Las Baulas National Marine Park of Guanacaste, Costa Rica, 10°20′53.4″ N, 85°51′44.5″ W). — Tsuyuki et al. 2021: 1–15 (mention only).

Marcusia ernesti – Lamothe-Argumedo et al. 1997: 15 (new record from Guaymas, Sonora, Mexico).

Distribution

Punta Marcial, Cabo Pulmo National Park, Baja California Sur; Puerto Peñasco, Sonora; Clarión Island, Revillagigedo Island, Manzanillo, Colima, México; Playa Carbón Beach, in Las Baulas National Marine Park of Guanacaste, Costa Rica.

Habitat

Benthic.

Remarks

Pericelis ernesti was initially established by Hyman (1953a) within the suborder Acotylea (family Cryptocelidae ) as Marcusia ernesti . Hyman (1953a) described it as a very peculiar acotyleo that presents characteristics of the suborder Cotylea , such as the distribution of the marginal eyes and the presence of a cement bag in the cement glands, which are emptied by a pair of ducts (see Hyman 1953a: 287), structures that sensu Hyman (1953a) are characteristic of the genera Pericelis and Enchiridium Bock, 1913 (suborder Cotylea ). Hyman (1955d: 263) later transferred the species to the genus Pericelis (family Pericelidae , suborder Cotylea ) based on the arrangement of the eyes, the coloration pattern (reticulate), the presence of a ventral sucker, and the reexamination of the male and female reproductive system. Faubel (1984b) subsequently reestablished the species as M. ernesti and transferred it to the family Anonymidae Lang, 1884 , but did not mention the criteria for the reestablishment of the species, only mentioning that Hyman (1953a) overlooked the presence of a sucker. Prudhoe (1985) established Marcusia Hyman, 1953 as a junior synonym of the genus Pericelis , but did not substantiate the criteria for this decision. On the other hand, Cuadrado et al. (2021), through a molecular analysis based on the 28S marker, validated the separation of Marcusia (represented by Marcusia alba ) from the genus Pericelis . This finding contrasts with Tsuyuki et al. (2021) who determined Marcusia as a junior synonym of Pericelis based on a molecular analysis based on the concatenation of the 18S and 28S genes. Therefore, the present study suggests a comprehensive review of the biological material of the 12 species of Pericelis .