Mexican Aphrodite Worm, Aphrodita mexicana

Mexican Aphrodite Worm, Aphrodita mexicana. Sea mouse provided by the commercial fishermen of the greater Los Cabos area, Baja California Sur, October 2009. Size: 5.5 cm (2.2 inches) x 2.4 cm (0.9 inches). Productive discussions with Dr. Richard Brusca, Tucson, AZ, noted and this identification should be considered tentative.

The Mexican Aphrodite Worm, Aphrodita mexicana (Kudenov, 1975) is a member of the Aphroditidae Family of Sea Mice, that is also known as the Gulf Sea Mouse and the Mexican Sea Mouse and in Mexico as gusano afrodita Mexicano. They obtain their common name from a thick layer dorsal notosetae (felt-like hairs) that gives them a mouse appearance.

The Mexican Aphrodite Worm is best described as a short worm with a fir coat. Their bodies are flattened with an elliptical profile are composed of ringed segments and their body cavities are filled with coelemic fluid affording them with rigidity. They are covered with dorsal setae (“many bristles”) and ventral nerosetae that are an iridescent golden brown in color. Their body has approximately 46 segments with the outer body margin outlined in spines. They are characterized by the relationship of the elytra to the notosetae, the palps, the length of the prostromium, the number of body segments and their color.The Mexican Aphrodite Worm reaches a maximum length of 12.5 cm (4.9 inches).

The Mexican Aphrodite Worm resides buried within mud and sand substrate and are found at depths between 46 m (150 feet) and 122 m (400 feet). They are normally covered with fine silt making them difficult to locate. The Mexican Aphrodite Worm is of scientific interest because they are one of the few marine species, in addition to Sea Cucumbers, that utilize anal respiration. They may be scavengers or predators that consume crustaceans or other polychaetaes. In turn they are preyed upon by various fishes. This Sea Mouse reproduce sexually, with external fertilization. Sea Mice of the Pacific have been poorly studied and very little is known about this specific species and its behavioral patterns.

In Mexican waters the range of the Mexican Aphrodite Worm has not been well documented but they are known to be endemic to the Sea of Cortez and along the coast of the mainland south to Guatemala.

From a conservation perspective the Mexican Aphrodite Worm has not been formally evaluated.  They are often caught as a by-catch by deep-water shrimp trawlers and are of limited interest to most.