Pseudoceros bicolor Verrill, 1901

Cuadrado, Daniel, Hernández-Gonzalez, Alejandro, Noreña, Carolina & Simões, Nuno, 2024, Polyclads (Platyhelminthes) in the southern Gulf of Mexico: unveiling biodiversity and descriptions of two new species, ZooKeys 1221, pp. 103-144 : 103-144

Pseudoceros bicolor Verrill, 1901

Fig. 8

Material examined.

Yucatan coast, Mexico • 1; Arrecife Alacranes; 22.4 ° N, 89.7 ° W; 3 m; 4 Nov. 2017; A. Hernández leg.; CRPPY - 0008; Campeche coast, Mexico • 1; Cayos sumergidos del Oeste; 20.4 ° N, 92.2 ° W; 10 m; 14 Sep. 2017; A. Hernández leg.; CRPPY - 0015 • 1; Cayos sumergidos del Oeste; 20.4 ° N, 92.2 ° W; 11.1 m; 13 Sep. 2017; D. Ortigosa leg.; CRPPY - 0027 • 1; Cayos sumergidos del Oeste; 20.4 ° N, 92.2 ° W; 11.7 m; 14 Sep. 2017; D. Ortigosa leg.; CRPPY - 0028; Yucatan coast, Mexico • 1; Bajos de Sisal; 21.2 ° N, 90.0 ° W; 1 m; 22 Feb. 2018; A. Hernández leg.; CRPPY - 0032; Quintana Roo coast, Mexico • 1; Mahahual; 18.6 ° N, 87.7 ° W; 7.7 m; 17 Mar. 2018; A. Hernández leg.; CRPPY - 0039; Campeche coast, Mexico • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 6.4 m; 19 Apr. 2018; A. Hernández leg.; CRPPY - 0048 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 2.2 m; 20 Apr. 2018; A. Hernández leg.; CRPPY - 0052 • 2; Cayo Arcas; 20.2 ° N, 92.0 ° W; 2.2 m; 20 Apr. 2018; A. Hernández leg.; CRPPY - 0054 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 2.2 m; 20 Apr. 2018; A. Hernández leg.; CRPPY - 0055 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 2.2 m; 21 Apr. 2018; A. Hernández leg.; CRPPY - 0061 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 2.2 m; 22 Apr. 2018; A. Hernández leg.; CRPPY - 0063 • 2; Cayo Arcas; 20.2 ° N, 92.0 ° W; 6.3 m; 22 Apr. 2018; A. Hernández leg.; CRPPY - 0067 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 7.5 m; 23 Apr. 2018; A. Hernández leg.; CRPPY - 0069 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 5.9 m; 23 Apr. 2018; A. Hernández leg.; CRPPY - 0070 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 5.3 m; 23 Apr. 2018; A. Hernández leg.; CRPPY - 0072 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 5.3 m; 24 Apr. 2018; A. Hernández leg.; CRPPY - 0074 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 9.9 m; 25 Apr. 2018; A. Hernández leg.; CRPPY - 0081 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 7.7 m; 25 Apr. 2018; A. Hernández leg.; CRPPY - 0084 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 3.4 m; 18 Aug. 2018; A. Hernández leg.; CRPPY - 0106 • 1; Cayo Arcas; 20.2 ° N, 92.0 ° W; 3.4 m; 18 Aug. 2018; A. Hernández leg.; CRPPY - 0107 .

Distribution.

Recorded in the Birds Islands, Bermuda ( Verrill 1901); Curaçao ( Marcus and Marcus 1968); the Caribbean coast of Colombia ( Quiroga et al. 2004 a); Florida, Virgin Islands, Jamaica, Belize, Honduras, Caribbean coast of Panama ( Rawlinson 2008; Litvaitis et al. 2019); Brazil ( Bahia and Padula 2009; Bahia et al. 2014, 2015; Bahia and Schrödl 2018). New record for the coasts of Campeche, Yucatán, and Quintana Roo (Mexican Caribbean), Mexico.

Description.

Body shape elongated with rounded anterior and posterior end, 2.5 cm in length and 1 cm in width. Dorsal pigmentation ranges from yellow to dark brown, with scattered white dots on its dorsal surface and with a yellowish or pale green marginal rim. Conspicuous dark marginal band interrupted by transverse white stripes (Fig. 8 A, B, D ). Pseudotentacles are simple folds with two clusters of eyes between them. Cerebral eyes arranged in the shape of an arrowhead, marginal eyes very numerous (Fig. 8 C ). Male and female gonopores located in the mid-region of the body, sucker posteriorly (Fig. 8 B, E ).

Remarks.

The pigmentation observed in P. bicolor in Yucatan aligns with the morphotype seen in Brazil ( Litvaitis et al. 2010: fig. 4 N). Preliminary analysis of the sequences obtained for the species (Suppl. material 1: table S 2) suggests that Mexican specimens appear to have a closer genetic relationship to those in Brazil than those in the Caribbean Sea and nearby regions. A comparative molecular analysis will help to understand their genetic relationship with other morphotypes described in the literature.

Figures

Figure 8. Pseudoceros bicolor A dorsal view B ventral view, sucker, oral pore, pharynx, male gonopore, female gonopore and intestine C detail of tentacular eyes, pseudotentacles D P. bicolor in situ E sagittal section, prostatic vesicle, seminal vesicle, male gonopore, stylet, vagina, female gonopore, female atrium Azan stained.