Notoplana annula Marcus & Marcus, 1968

Fig. 21

Material examined.

Campeche coast, Mexico • 5; Cayos sumergidos del Oeste; 20.4°N, 92.2°W; 5 m; 10 Sep. 2017; A. Hernández leg.; CRPPY -0009 • 8; Cayos sumergidos del Oeste; 20.4°N, 92.2°W; 0 m; 10 Sep. 2017; A. Gutiérrez leg.; CRPPY -0010 • 1; Cayos sumergidos del Oeste; 20.4°N, 92.2°W; 0 m; 11 Sep. 2017; A. Hernández leg.; CRPPY -0012 • 5; Cayos sumergidos del Oeste; 20.4°N, 92.2°W; 11 m; 11 Sep. 2017; A. Gutiérrez leg.; CRPPY -0016 • 2; Cayos sumergidos del Oeste; 20.4°N, 92.2°W; 13 m; 14 Sep. 2017; A. Gutiérrez leg.; CRPPY -0017 • 1; Cayos sumergidos del Oeste; 20.4°N, 92.2°W; 13 m; 14 Sep. 2017; A. Gutiérrez leg.; CRPPY -0023 .

Distribution.

Recorded in Piscadera Bay and Fuik Bay, Curaçao and Virginia Key, Florida (Marcus and Marcus 1968). New record in the Gulf of Mexico: Campeche, Mexico.

Description.

Body shape elongated and smooth, 0.7 cm in length and 0.3 cm in width. Pigmentation varies from whitish beige to greenish hues. Intestinal extensions well-branched, not anastomosing, extending to body margin, with contents visible due to transparency (Fig. 21 A). Tentacular eyes form rounded cluster located in the brain, crossed by two, parallel, elongated clusters of cerebral eyes. Marginal eyes absent (Fig. 21 B). Pharynx elongated, tapering along midsection of body. Male and female gonopores positioned posterior to the pharynx in the second 1 / 2 of the body.

Heading as above. Male copulatory system comprises an elongated seminal vesicle with two broad sperm ducts proximally (Fig. 21 C, D). Prostatic vesicle interpolated, connected via a narrowing to the ejaculatory duct and the penis papilla. Ejaculatory duct with thin, long, curved stylet covered with a penial sheath. Atrium wide proximally and tubular distally. Female apparatus comprises a wide, densely ciliated female antrum, a ciliated external vagina with a sinuous course, the internal vagina, and Lang’s vesicle. Cement glands open into the vagina externa and oviducts into the vagina interna (Fig. 21 C, D).