California Flatworm, Hylocelis californica

California Flatworm, Hylocelis californica. Flatworm collected from a tidal pool in the greater Los Cabos area, Baja California Sur, January 2012. Size: 2.4 cm (1.0 inch) x 1.4 cm (0.6 inches).

Phylogeny:  The California Flatworm, Hylocelis californica (Heath and McGregor, 1912), is a member of the Cryptocelididae Family of Flatworms.

Morphology:  The California Flatworm has unsegmented, soft-bodies that may be gray, tan or whitish in color, with darker, branching lines. These lines start at the center line and progress to the frilled margins. The California Flatworm reach a maximum size of 2.4 cm (1.0 inch) x 1.4 cm (0.6 inches).

Habitat and Distribution:  California Flatworms are fairly abundant being found under large rocks with gravel and sand substrate in the upper middle intertidal zone. They are found in all Mexican waters of the Pacific Ocean.

Synonyms: Alloioplana californica, Planocera californica, Pseudoallioplana californica, and Stylostomum californicum.