Red-colored Keyhole Limpet Shell, Fissurella rubropicta

Red-colored Keyhole Limpet Shell, Fissurella rubropicta. Shell collected off the beach in the greater Cabo San Lucas area, Baja California Sur. March 2014. Size: 2.5 cm (1.0 inch) x 1.4 cm (0.6 inches). Collection, photograph and identification courtesy Bob Hillis, Ivins, Utah.

Phylogeny: Red-colored Keyhole Limpet Shell, Fissurella rubropicta (Pilsbry, 1890), is a gastropod mollusk that is a member of the Fissurellidae Family of Keyhole Limpet Shells. The genus Fissurella is one of forty-five genera in this family, and there are fifty-five species in this genus. They are also known as the Red-painted Keyhole Limpet Shell and in Mexico as Lapa  Pintado de Roja.

Description: The Red-colored Keyhole Limpet Shell have an ovate, high, conical, profile. The shell is slightly wider in the center and narrower at both ends. The oval keyhole is set slightly forward of the shell’s center. The exterior is sculpted with rough, radial ribs. The exterior of the shell has black and red ribs on a white background. The interior of mature shells is white with red or purple staining around the keyhole. Immature specimens are pale green, with red around the keyhole. Red-colored Keyhole Limpet Shells reach a maximum length of 3.0 cm (1.2 inches) in length and 1.7 cm (0.7 inches) in height.

Habitat and Distribution: Red-colored Keyhole Limpet are found attached to rocks in the intertidal zone, and to depths up to 35 m (115 feet). They are a subtropical to tropical Eastern Pacific species that are found in all Mexican waters of the Pacific Ocean with the exception that they are absent from north of Cedros Island, Baja California, along the central and northwest coasts of the Baja Peninsula.

Ecology and Behavior: Red-colored Keyhole Limpets are herbivorous grazers  that feed primarily on algae. They are gonochoric and reproduce sexually, through broadcast spawning, with external fertilization. Their engagement in any type of commensal, parasitic, or symbiotic relationship has not been formally documented. The Red-colored Keyhole Limpet has not been formally evaluated from a conservation perspective. However, they are fairly common with a relatively wide distribution and should be considered to be of Least Concern.

Synonyms: None