Bursidae

Bursidae, commonly known as frog shells, are a family of medium-sized to large sea snails, marine gastropod mollusks in the superfamily Tonnoidea. The shells of these snails are usually thick and heavy, with a distinctive, bulbous, or “frog-like” appearance. This characteristic morphology has given them their common name. The family includes about 35 described species in four genera.

Bursa tuberosissima

Warty Frog Shell – Bursa bufonia

Characteristics

The shells of Bursidae are generally characterized by:

  • A thick, solid, and often heavy construction.
  • A rounded, bulbous, or "frog-like" shape.
  • A short spire with a wide aperture.
  • A distinct siphonal canal, which is often long and curved.
  • A smooth, glossy, or sculptured surface.
  • Coloration ranging from brown and gray to yellow and orange, often with intricate patterns.

The animal within the shell is a carnivore, feeding on other mollusks, especially those belonging to the families Muricidae and Nassariidae. They use a radula, a chitinous ribbon covered with teeth, to rasp away at their prey's shells. The shells of Bursidae are also known for their strong, durable structure, making them prized by shell collectors.

Environment

Bursidae snails are found in tropical and subtropical waters worldwide. They typically inhabit rocky and sandy bottoms, coral reefs, and seagrass meadows. Some species are known to burrow in the sediment. Bursidae are generally found in shallow waters, although some species can be found at depths of up to 100 meters.

Genera

The family Bursidae comprises four recognized genera:

  • Bursa Röding, 1798
  • Eburna Röding, 1798
  • Gyrineum Link, 1807
  • Ranella Lamarck, 1799

References

  • Bouchet, P.; Rocroi, J.-P.; Frýda, J.; Hausdorf, B.; Ponder, W.; Valdés, Á.; Waren, A. (2005). "Classification and nomenclator of gastropod families". Malacologia 47 (1-2): 1–397.
  • Gofas, S.; Le Renard, J.; Bouchet, P. (2001). "Mollusca, in: Costello, M.J. et al. (Ed.) European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification". Collection Patrimoines Naturels 50: 180–213.
  • Neville, A. C. (1979). Biology of the Mollusca. Academic Press.