Phaenoplana caetaria Perez-Garcia, Norena & Cervera 2018

Phaenoplana caetaria Pérez-García, Noreña & Cervera, 2018 Fig. 15 Material examined. Specimen found in the field, Station 16, 19 May 2015, 13 mm; specimen found in the field, Station 16, 19 May 2015, 21 mm; specimen found in the field, Station 17, 19 April 2015, 24 mm. Type locality. Punta Carnero, Cádiz, Spain. Description. Stylochoplanidae with elongated body, wider anteriorly, and folded within the margins. Length between 24 mm and 13 mm (19.3 ± 5.69). Colour of the dorsal surface light brown with yellowish spots (Fig. 15 A, C). Ventral surface pale brown. Tentacles absent. Tentacular and cerebral eyes arranged in two clusters, with approximately 15 tentacular eyes and 27 cerebral eyes in each cluster (Fig. 15 B, D). Pharynx ruffled, positioned slightly anteriorly, between the first and second thirds of the body. Opening of the mouth in the last third of the pharynx. Genital pores separated. Male copulatory apparatus composed of a true seminal vesicle, an interpolated prostatic vesicle, and a penis papilla with a penis rod. Female complex consists of a well-developed external vagina (vagina bulbosa) and reduced Lang’s vesicle (for more details, see Pérez-García et al. 2019). Remarks. After the original description of Phaenoplana caetaria (Pérez-García et al., 2019), Oya and Kajihara (2019) described a new species of Phaenoplana from Japan (P. kopepe), increasing the number of species in this genus to six. In this context, P. kopepe is differentiated from P. caetaria by the presence of tentacles, a muscular bulb that surrounds the prostatic vesicle, the shaft of the penis, and the male atrium, a character that is missing in P. caetaria, which shows instead a very characteristic twisted penis rod. Representatives of Phaenoplana have a predominantly Pacific distribution (5 known species) compared to the Mediterranean or Atlantic (two species), although the record of P. caetaria shows a clear expansion of the specific distribution of Phaenoplana. Biology. This species is found under stones in the intertidal area of La Ballenera and Punta Carnero Beach, Cadiz, Spain.