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Family Harpidae - harp shells
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Order |
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Class |
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Gastropoda |
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No. of Genera in Ref. |
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No. of Species in Ref. |
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Environment |
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Fresh : No |
Brackish : No |
Marine : Yes |
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First Fossil Record |
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Remark |
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Shell globular-ovate to potbellied in shape, with an inflated body whorl and small conical spire. Surface glossy, with usually vivid colour patterns, and with strong axial ribs ending in sharp points on the shoulder. Spiral sculpture mostly lacking. Periostracum absent. Aperture large, elongate-ovate, inner lip covered by a generally smooth, glossy callus. Columella without folds. Anterior siphonal canal a well marked, short and wide notch. Operculum absent or vestigial. Head small, with a long siphon between 2 slender tentacles that bear conspicuous eyes on their external lateral base. Foot very large and fleshy, divided into 2 parts: anterior part greatly expanded laterally, posterior part elongate and pointed behind. Active, burrowing animals, living in sandy bottoms in depths ranging from low tide levels to the deep shelf zone. Harps can glide rapidly over the substrate by means of the huge, leaf-shaped foot, or can use the anterior part of the foot to burrow, forming a low mound from which the siphon protrudes. Carnivores or occasionally scavengers, preying on small crabs and shrimps, which are trapped by the foot, then coated with mucus and adhering sand grains, and probably killed and partially digested by salivary secretions. When disturbed or attacked, the animal can cast off the hind part of the foot, which continues wriggling to distract the predator. Sexes separate. Eggs laid in capsules connected in a row on a hard substrate, hatching as free-swimming planktonic larvae (genus Harpa) or as crawling juveniles (genus Morum). Although still locally eaten, harps are nowadays mainly collected for their beautiful, highly prized shells (Ref. 349). |
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