Pseudoceros rawlinsonae Bolaños, Quiroga & Litvaitis, 2007

Fig. 9

Material examined.

Yucatan coast, Mexico • 1; Bajos de Sisal; 21.2°N, 90.0°W; 1 m; 22 Feb. 2018; A. Hernández leg.; CRPPY -0029 ; Quintana Roo coast, Mexico • 1; Mahahual; 18.6°N, 87.7°W; 5.3 m; 17 Mar. 2018; A. Hernández leg.; CRPPY -0036 ; Campeche coast, Mexico • 1; Cayo Arcas; 20.2°N, 92.0°W; 9.3 m; 21 Apr. 2018; A. Hernández leg.; CRPPY -0056 • 1; Cayo Arcas; 20.2°N, 92.0°W; 5 m; 25 Apr. 2018; A. Hernández leg.; CRPPY -0085 .

Distribution.

Pseudoceros rawlinsonae has been recorded in the Caribbean Sea: Virgin Islands, Honduras, Jamaica, Bahamas, Curaçao; the Gulf of Mexico, Florida (Bolaños et al. 2007; Litvaitis et al. 2010, 2019); Brazil (Bahia et al. 2014, 2015; Bahia and Schrödl 2018). This is the first record for the coasts of Quintana Roo (Mexican Caribbean), Campeche and Yucatán, Mexico.

Description.

Body shape elongated with rounded anterior and posterior end, 1.2 cm in length and 0.5 cm in width. Pigmentation brownish yellow to black with scattered white dots (Fig. 9 A, D). A white marginal band with grey to black stripes encircles body margin. A characteristic golden yellow or orange marginal line marks external rim. Pseudotentacles simple folds (Fig. 9 A, B). Cerebral eyes arranged in arrowhead shape, tentacular eyes more densely arranged along margins of pseudotentacles. Two frontal eye clusters positioned between two pseudotentacles. Ruffled pharynx in anterior region, oral pore situated centrally. Female and male gonopores separate and located in mid-region of the body, with sucker posterior to them (Fig. 9 C).

Remarks.

Pseudoceros bicolor and P. rawlinsonae are closely related. Externally, the primary distinguishing features between the two are the prominent white submarginal band and the orange rim that characterise P. rawlinsonae . A study by Litvaitis et al. (2010) provided a detailed comparison between both species, examining both morphological and molecular data, specifically through analysis of the 28 S gene.