Phaenocelis peleca Marcus & Marcus, 1968

Fig. 18

Material examined.

Campeche coast, Mexico • 2; Cayo Arcas; 20.2°N, 92.0°W; 2.2 m; 20 Apr. 2018; A. Hernández leg.; CRPPY -0053 • 1; Cayo Arcas; 20.2°N, 92.0°W; 9.3 m; 24 Apr. 2018; A. Hernández leg.; CRPPY -0077 .

Distribution.

Piscadera Bay, Curaçao, Caribbean Sea (Marcus and Marcus 1968). New record from the Campeche coast and Gulf of Mexico.

Description.

Body shape oval and tapers in the posterior region, 4 cm in length, 2 cm in width. Compact consistency. Milky-translucent colouration, with translucent margin (Fig. 18 A, C). Intestinal branches visible through transparency. Well-differentiated tentacular eyes; cerebral eyes in scattered, elongated clusters; abundant marginal eyes along the entire body margin (Fig. 18 B). Pharynx ruffled, elongated and narrow. Male and female gonopores close to the oral pore. Reproductive system. Male reproductive system (Fig. 18 D, E) consists of a short, curved penis papilla, an elongated prostatic vesicle, and a short seminal vesicle with distally broad seminal ducts. Female reproductive system, poorly developed in the studied specimens (Fig. 18 D, E), consists of an elongated vagina externa, surrounded by cement cells, a vagina interna and Lang’s vesicle.

Remarks.

The specimen of the Gulf of Mexico aligns with the description of Phaenocelis peleca provided by Marcus and Marcus (1968). Nonetheless, Mexican P. peleca specimens are larger than Caribbean ones (4 cm vs 2 cm), but present a short penis papilla compared to that given in the original description. Female apparatus differences are also observed, with the Cayo Arcas P. peleca having an elongated Lang’s vesicle compared to the round one in Caribbean individuals. These differences may be due to specimen size and maturity.