Ommatoplana mexicana (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 : 29-30

Ommatoplana mexicana (Hyman, 1953)

Mexistylochus tuberculatus Hyman, 1953a: 291–293 , figs 25–26 (type locality: Miramar Beach, Guaymas, Sonora, Mexico).

Ommatoplana mexicana – Hyman 1955a: 74 (new combination, new name); 1955b: 9 (new combination). — Faubel 1983: 69 (identification keys). — Brusca 2005: 69 (checklist).

Distribution

Cabeza Ballena Point, Baja California Sur, Miramar Beach, Guaymas, Sonora, Mexico.

Habitat

Benthic.

Remarks

Ommatoplana mexicana was described by Hyman (1953a) as Mexistylochus tuberculatus . However, through a comprehensive review of the reproductive system of two specimens from Saipan Island, Northern Mariana Islands (western Pacific), Hyman (1955a, 1955b) determined that these specimens were assignable to the genus Ommatoplana , and that Mexistylochus is synonymous to Ommatoplana .

Initially Hyman (1953a) did not place the species within the genus Ommatoplana because the original specimen was incomplete.

Ommatoplana mexicana is characterized by an oval body with brown dorsal coloration, with white blunt-ended protuberances (tubercles); marginal eyes distributed throughout the body margin, cerebral eyes, frontal eyes, and tentacular eyes arranged in a circular fashion and with approximately 30 eyes each. The elongate pharynx occupies two-thirds of the body and has approximately 20 pharyngeal lobes. The male reproductive system features a tripartite seminal vesicle, a prominent oval prostatic vesicle located horizontally to the seminal vesicle and an inert conical penis papilla protected by a penis sheath. The female reproductive system features a muscular ductus vaginalis with scalloped inner walls and a pore posterior to the female gonopore, a tubular female atrium, and an elongated vagina oriented towards the posterior region of the body and Lang’s vesicle is absent.