Wide-mouth Coral Shell, Galeropsis monodonta
Wide-mouth Coral Shell, Galeropsis monodonta. Shell collected off the beach in the greater Los Cabos area, Baja California Sur, May 2015. Size: 2.0 cm (0.8 inches) x 1.2 cm (0.5 inches).
Phylogeny: The Wide-mouth Coral Shell, Galeropsis monodonta (Blainville, 1832), is a member of the Muricidae Family of Rock Shells. The genus Galeropsis is one of one hundred ninety-eight genera in this family, and this is the only species in this genus. They are also known as the Monodonta Coral Shell and as Quoy’s Coral Shell. In Mexico they are known as Caracol del Coral de Boca Ancha. The species name monodonta comes from the Greek words meaning “one tooth” and refers to the single tooth found in some individuals in this species. The alternative name “Quoy”, as well as the synonymized genus Quoyula, are named after Jean René Constant Quoy. Quoy was a surgeon, naturalist, and artist who served on French voyages of exploration in the early 1800’s. Quoy is credited with noting the importance of sketching marine invertebrates while still alive before loss of natural colors.
Description: The Wide-mouth Coral Shell is a medium-sized shell that has three or four whorls, and a short and blunt spire. They can be somewhat flattened in profile. The aperture is large and ovate. Some individuals have a tooth at the anterior end of the inner column. The exterior of the shell is chalky, rough, and sculpted with spiral ridges. They are white in color. The interior is smooth and white with varying amounts of pink and/or purple around the perimeter. Wide-mouth Coral Shells reach a maximum of 3.5 cm (1.4 inches) in length and 2.1 cm (0.8 inches) in height.
Habitat and Distribution: Wide-mouth Corals are found on coral in the intertidal zone, and at depths up to 33 m (100 feet). They are found in tropical waters of the Indian and Pacific Oceans and they have been introduced to the Mediterranean Sea. They are found in all Mexican waters of the Pacific Ocean, including the Revillagigedo Islands, with the exception that they are absent from north of Guaymas, Sonora, in the Sea of Cortez.
Ecology and Behavior: Wide-mouth Corals are corallivores that feed on coral polyps, especially corals in the Pocillopora genus. They are gonochoric and reproduce sexually, with internal fertilization. Their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented. From a conservation perspective the Wide-mouth Coral has not been formally evaluated. However, they are fairly common with a very wide distribution and should be considered to be of Least Concern.
Synonyms: Coralliophila madreporara, Coralliophila madreporaria, Coralliophila madreporarum, Coralliophila monodonta, Purpura madreporarum, Purpura monodonta, Purpura monodonta, Quoyula madreporarum, Quoyula monodonta, and Rhizochilus madreporarum.