False Limpet Shells of the Siphonariidae Family

One False Limpet Shell of the Siphonariidae  Family can be found in this website:

Maura False Limpet Shell
Siphonaria maura

Phylogeny: False Limpet Shells of the Siphonariidae Family are gastropod mollusks in the order Siphonariida. The superfamily Siphonaroidea is the only superfamily in this order and Siphonariidae is the only family in this superfamily. The Family Siphonariidae contains no subfamilies, but it consists of four genera – Aporemodon with one species, Siphonacmea with one species, Siphonaria with one hundred thirty-one species, and Williamia with six species. These shells are also commonly known as Air-breathing Limpets.

Description: False Limpet Shells, as the name implies, resemble the True Limpet Shells of the Lottiidae Family in appearance. They have asymmetrical outlines that are round or oval. The most notable difference between the two is that False Limpet Shells are air breathing. They lack the gill structures that most other mollusks have. Instead, they have either a mantle cavity that functions like gills and lungs, or they have secondary gills located within the mantle cavity. False Limpet Shells are easily identified in that they have a special respiration canal on the interior that runs to the right margin. This canal allows the live snail to clamp down tightly on hard substrate and still circulate air into the mantle cavity. Like True Limpets, False Limpets have a flattened conical shape but they do not have a spiral. The apex is often eroded. The exterior of these shells may be smooth or sculpted with radial ridges. These ridges sometimes extend to the margins, giving the shell the shell  a scalloped edge. Shells in this family tend to be whitish, with varying amounts of brown or gray radial rays or lines. The interior muscle attachment scar has a gap where the respiratory canal passes. False Limpet Shells are small to medium in size, with the larger species reaching around 8.4 cm (3.3 inches) in diameter.

Habitat and Distribution: False Limpet Shells are found on rocks, rubble, coral, and other hard surfaces. They live throughout the intertidal zone, and sometimes slightly above the hightide line. They are found globally in tropical to temperate waters. Seven species from the Siphonariidae Family are found in Mexican waters.

Natural History: False Limpet Shells are grazers that feed primarily on micro algae. In turn they are preyed upon by crabs, fish, and predatory mollusks. They are simultaneous hermaphrodites and reproduce sexually with internal fertilization. The eggs are laid as a gelatinous mass.