Stylochus mistus Ramos-Sánchez, Carrasco-Rodríguez, García-Madrigal & Bastida-Zavala, 2021

Stylochus mistus Ramos-Sánchez et al., 2021: 304–309, figs 2a–f, 3a–g, 4a–g, 5a–c (type locality: Tangolunda, Bahías de Huatulco, Oaxaca, Mexico).

Distribution

Tropical Eastern Pacific. Central coast of Oaxaca: Tangolunda Bay, Bahías de Huatulco, Oaxaca.

Habitat

Fouling. The polyclads were found inside the shells of Paraconcavus pacificus (Pilsbry, 1916), which were part of the fouling of a marine sensor (SeapHOx ®), at a depth of approximately 20– 25 m.

Remarks

Stylochus mistus has a beige background color with scant orange to light brown pigmentation, and black transverse spots which, when fused, give the appearance of lines, mainly in the anterior marginal region of the body. The nuchal tentacles are orange, and the body margin is orange or pink. The species has marginal, tentacular, and cerebral eyes. Its gonopores are separated. The male reproductive system features prominent prostatic vesicle, which is oval, and polyglandular, an elongayed and prominent seminal vesicle, and a short the penis papilla. The female reproductive system features a scarcely developed, narrow, and short vagina, oriented towards the anterior region of the body, and lacks a Lang’s vesicle.