The ovulids are a widespread family, occurring mostly in tropical and subtropical waters, with most species in the Indo-West Pacific region. But a few species live in temperate waters.

Ovulids are carnivorous molluscs that feed on polyps and tissues of Anthozoa (as do the genera Cyphoma and Pseudocyphoma). They live on, and eat, soft corals and sea fans, and they are usually regarded as ectoparasites of these sessile colonial organisms, to which they are anchored by a long and narrow foot. This extreme specialisation in their alimentary regime has caused important morphological modifications to their radula.

Ovulids mostly have smooth shiny shells with a very long aperture and a very low or invisible spire. The shell can be pyriform (shaped like a pear), ovate (egg-shaped) to sub-ovate, cylindrical or lanceolate (lance-shaped). The shell is often monochromatic white, but in some species the shell is pink or reddish.

In a few species of ovulids, the shell quite closely resembles that of cowries. However in many other species, the shells are so elongate that they do not so much resemble the shells of that closely related family.

When these snails are alive, the mantle completely covers the shell almost all of the time. Pictures of living animals usually show the brightly colored and decorated mantle, which looks very different from the often rather plain, shiny surface of the shell. The color patterns of the mantle closely resemble the color patterns of the host species. This is due to the phenomenon of “alimentary homochromy” (obtaining the same color as the host by feeding on the host). This phenomenon gives them a remarkable camouflage ability.