False Cowry Shells of the Ovulidae Family

Four False Cowry Shells of the Ovulidae Family can be found in this website:

Phylogeny: False Cowry Shells of the Ovulidae Family are gastropod mollusks in the Littorinimorpha order. This order is large and very diverse in shape including snail-like, cowry-shaped, and limpet-like. Most are marine species but some are found in freshwater or on land. They all have a twisted shell and a muscular foot that is used for movement. The key characteristic is that they all exhibit torsion, which is a process where the body twists so that the anus, gills, mantle cavity, and reproductive organs all point forward. There are sixteen superfamilies in this large order. The Ovulidae Family is one of three families in the superfamily Cypraeoidea. The Ovulidae Family consists of two stand alone genera and six subfamilies – Aclyvolvinae with one genus and four species, Cypraediinae with two genera and four species, Ovulinae with seven genera and forty-seven species, Pediculariinae with three genera and twenty-one species, Prionovolvinae with twenty-four genera and one hundred forty-one species, and Simniinae with six genera and forty-four species. Shells in this family, along with shells from the Eocypraeidae Family (with only  two valid species, the majority of family members now being extinct), are considered to be Cowry Allies. False Cowry Shells are also commonly known as Egg Shells, Egg Cowries, and Ovulids.

Description: Ovulid Shells resemble cowry shells in that many are egg-shaped, have shiny exteriors, and some have teeth along their elongated apertures. They differ from cowries in that they are generally smaller, their teeth are located only along the outer aperture lip, and although shiny, they are not as shiny as cowries. Ovulids vary in shape from globose to spindle-shaped. Most are thin-shelled. The spire is concealed under the body whorl. All have an anterior and posterior siphon notch or canal and elongated apertures.  Some have very long siphonal canals on each end. Most of these shells are smooth but some are sculpted with pustules, transverse striations, or a transverse dorsal keel. Unlike cowries, most Ovulid Shells are one solid color such as white, gray, pink, purple, bluish, or brown. Some exceptions display banding or blotching. The live animal is usually very colorful. They lack an operculum and periostracum. Ovulid Shells range from very small, around 0.5 cm (0.18 inches) in length to large being over 18 cm (7.1 inches) in length.

Habitat and Distribution: Ovulids are found on soft coral, sea fans, sea pens, and whip corals. They live in the lowest intertidal zone and to depths exceeding 1,000 m (3,280 feet). They are found worldwide in subtropical to tropical seas. Four species are found in Mexican waters.

Natural History: Ovulids are ectoparasitic corallivores that feed on the polyps of their host coral. The mantle of many species match the color and texture of their hosts. By extending their mantle they are camouflaged and the mantle keeps their shells shiny. Some species utilize toxins from their polyp diet, which they store in their mantle, as an additional defense mechanism. Despite these defenses, Ovulid Shells are preyed upon by fish, crabs, and lobsters. Ovulids are gonochoric and reproduce sexually, with internal fertilization. The females lay their eggs within mucus nets that are attached to, or at the base of, their host corals. Larger Ovulids have long been used for food and their shells for ceremonial or ornamental items amongst indigenous peoples. Some species are eagerly sought by shell collectors, to the point of over collecting.