Harp Shells of the Harpidae Family
Two Harp Shells of the Harpidae Family can be found in this website:
Phylogeny: The Harp Shells of the Harpidae Family are gastropod mollusks in the Neogastropoda order. Neogastropods are characterized by having a long siphon canal, a well-developed siphon notch, and a specialized radula. Many species in this order have a narrow aperture. Neogastropods are primarily marine snails and most of the well-known shell families are in this order. They are temporarily placed in the Neogastropoda incertae sedis superfamily (incertae sedis is Latin for uncertain seating, meaning they are not sure where it goes). Harpidae is one of four families within this superfamily. There are two subfamilies in the Harpidae Family – Harpinae (which has two genera and twenty species) and Moruminae (which has one genus and forty-two species).
Description: The Harpidae Family consists of two groups of shells, the Harp Shells and the Morum Shells. Harp Shells are egg-shaped and have a polished exterior. Their body whorl makes up the great majority of the shell, and they have low spires. They are sculpted with strong axial ribs, which may form points where they join the shoulder. Some species also have spiral ridges. The shells are beautifully decorated with scalloped patterns that may include dark brown, purplish brown, lavender, rose, and tan. The aperture is large and flared with a notch at the bottom. The inner lip is smooth and covered with glossy callus. The columella lacks folds. These shells do not have a periostracum or an operculum. The animal is larger than the shell and the foot extends well beyond the shell. Morum Shells differ from Harp Shells in that they may have a higher spire and a more narrow aperture, which may have dentition (“teeth”) along the outer lip. The largest species in the Harpidae Family reach a maximum of 13.0 cm (5.1 inches) in length.
Habitat and Distribution: Harps are found on sand and mud substrates. They live in the lower intertidal zone and to depths over 250 m (820 feet). They are found worldwide in subtropical and tropical seas. Four species from the Harpidae Family are found in Mexican waters.
Natural History: Harp Shells bury in sand during the day and emerge at night as nocturnal predators. They feed primarily on crabs, shrimp, and carrion. They feed by covering their prey with their foot and enveloping it in mucous. The prey is partially digested by salivary secretions. In turn they are preyed upon by crabs, fish, and predatory mollusks. As a defense mechanism, Harp Shells have the ability to amputate a rear portion of their foot. The amputated foot continues to wiggle, distracting the predator, while the Harp Shell crawls away. Harp Hhells may be gonochoric or simultaneous hermaphrodites. They reproduce sexually, with indirect fertilization (males deliver sperm packets, which the female uses to fertilize the eggs externally). The eggs are laid in protective capsules. Harp Shells are edible and are the target of small commercial fisheries in some regions. They are also eagerly sought by shell collectors because of their elegant shells.