Ovulinae

Ovulinae typically have either an ovate (egg-shaped), lanceolate (lance-shaped) or pyriform (pear-shaped) shell. The spire is not prominent, and the funiculum is absent. The anal canal is twisted anteriorly.[1] The extremities are usually short and the outer lip of the aperture has well-developed teeth.[2] The mantle usually completely covers the shell in life. The mantle is typically brightly colored, while the shell is often white, although in some cases the shell is pink or even red. This can easily be seen in photographs of the snails.

Ovulines live parasitically on anthozoans (of the phylum Cnidaria), feeding off of the exterior of the organism. In these cases, the ovuline species in question has almost always evolved a size, shape, and color that mimics the appearance of the cnidarians and camouflages itself with it. Alimentary homochromy, or the process of gaining the pigmentation of a host by feeding on the host, further helps to hide ovulines amongst their prey. Most members of the Ovulines live in tropical and subtropical waters.[3]

Species within the family Ovulidae have been reclassified numerous times throughout the 19th, 20th, and 21st centuries, and this has also affected the classification of the subfamily Ovulinae (Shilder 1932, Allan 1956, Cate 1973, Fehse 2001). Historically, the Ovulids were separated into two subfamilies, Ovulinae and Volvinae, although this is no longer true. The taxonomy has changed often.[2]