Mitella Limpet Shell, Lottia mitella: The Mitella Limpet Shell is a black shell with a raised white cap that has a dark rounded hourglass in the middle and alternating dark and white lines extending into the margin. The shell surface is smooth with an eroded apex. The internal surface is a dark with irregular dark and white bars around the fringes.
Note: this shell also appears in the literature as Acmaea mitella and Collisella mitella but both the Acmaea and Collisella Genus were consolidated into the Lottia genus in 2007.
They reach a published maximum size of 1.3 cm (0.5 inch) x 1.0 cm (0.4 inches) x 0.6 cm (0.25 inches); however the bottom pictured shell below is significantly larger.
The Mitella Limpet Shell is very similar to the Checkered Limpet Shell but has more ribs (45 to 47 versus 30 to 32).
In Mexican waters they are only known from Mazatlán south to Guatemala around the coast of the mainland with the collection below documenting a significant range extension for this species.
The Mitella Limpet Shell is a medium sized member of the Lottiidae Family, which are the True Limpets known in Mexico as Lapas. The members of the family are characterized by having a horseshoe-shaped muscle scar (the scar left by the margin of the mantle and the foot retractor muscles) and conical shells. The coiling of the shell has been completely lost and internally they have only a single ctedinum (breathing apparatus). They reside primarily on rocks in protected areas in the mid-intertidal zone. They feed on algae which they scrape off the substrate with their radula (tongue).