Interplana sandiegensis

Interplana sandiegensis (Boone, 1929) Planocera sandiegensis Boone, 1929: 33, pl. 2 fig. 6, p1. 3 fig. 10 (type locality: La Jolla, California, United States). Alloioplana sandiegensis – Hyman 1953a: 349–350, figs 111–113 (new combination). — Brusca 1980: 70 (identification keys); 2005: 69 (new record from Corona del Mar, California; Espíritu Santo, San Gabriel Bay, Baja California Sur, Mexico). Interplana sandiegensis – Faubel 1983: 104 (new combination). Distribution Corona del Mar, San Diego Bay, La Jolla, California; Punta Marcial reef, Baja California Sur; Puerto Peñasco, Sonora, Mexico. Habitat Benthic. Remarks Interplana sandiegensis was initially included in the genus Planocera characterized by the absence of a seminal vesicle, Hyman (1953a) later transferred it to the genus Alloioplana. However, as Alloioplana is characterized by the absence of nuchal tentacles and Lang’s vesicle, Faubel (1983) subsequently transferred the species to the genus Interplana. Interplana sandiegensis has a light brown coloration and dark brown spots, with an olive-green variant in some specimens; an oval body rounded anteriorly and slightly pointed posteriorly, nuchal tentacles, tentacular and cerebral eyes, and a pharynx located in the central region of the body, slightly oriented towards the anterior region of the body. The male reproductive system features an elongated oval seminal vesicle, an oval interpolated prostatic vesicle, and a cirrus sac armed with elongated sclerotized teeth located in the dorsal and ventral region of the cirrus (Hyman 1953a: 348, fig. 112). Faubel (1983) described this structure as a complex feature of the penis papilla (“complicated armed penis stylet”) and named it a stylet. The female reproductive system has a bulbous vagina positioned anterior to the female gonopore and a tripartite Lang’s vesicle positioned posterior to the female gonopore.