Gnesioceros sargassicola Mertens, 1832

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

Gnesioceros sargassicola Mertens, 1832

Fig. 23 A

Material examined.

Quintana Roo coast, Mexico • 2; Mahahual; 18.6 ° N, 87.7 ° W; 7.7 m; 17 Mar. 2018; A. Hernández leg.; CRPPY - 0037 .

Distribution.

Currently, Gnesioceros sargassicola is known from Bermuda ( Hyman 1939) and Florida to Texas, Gulf of Mexico US coast ( Hyman 1954); on Sargassum algae, near the west coast of Africa ( Moseley 1877); Boa Vista Island, Cape Verde ( Laidlaw 1903); Gaira Bay, Colombia ( Quiroga 2008); Curaçao, Bonaire, Little Bonaire, ( Netherlands Antilles, Caribbean), Saint Barthelemy, France Antilles; Bahia Fosforescente, Puerto Rico; Marine Biological Station, Virginia Key, Florida, USA; Central Atlantic Ocean, Sargasso Sea ( Marcus and Marcus 1968). New record for the coasts of Mahahual, Quintana Roo (Mexican Caribbean).

Description.

Dorsoventrally flattened body, anteriorly widened with a shallow constriction after the tentacles, undulated body margins, and a blunt-tailed posterior end, 0.8 cm in length and 0.3 cm in width. Yellowish grey background colouration with numerous, rounded, orange or brown spots. Narrow elongated pharyngeal pouch with a central oral opening (Fig. 23 A ).

Biology.

Associated with Sargassum algae.

Figures

Figure 23. A Gnesioceros sargassicola Photograph in situ of the specimen captured B – E Idioplana atlantica B dorsal view of a live individual photographed on a black background C specimen photographed after fixation D, E specimens photographed in situ with the characteristic pigmentation rings.