Limpet

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iLimpets
Patella vulgata limpets in their natural habitat (here northwestern Galicia). One animal was separated from the rock and turned over for the photograph to have a view of the underside and muscular foot.
Scientific classification
Kingdom: Animalia Phylum: Mollusca Class: Gastropoda Order: Patellogastropoda Lindberg, 1986
Suborders
See text.

Limpets are marine molluscs in the order Patellogastropoda with flattened, cone-shaped shells. They live throughout the intertidal zone, from the high zone (upper littoral) to the shallow subtidal on the rocky coasts of most oceans. Limpets can be commonly found attached to rocks, looking like little disks or bumps on the rock surface. They attach themselves to the substratum using pedal mucus and a muscular "foot", which enables them to remain attached through dangerous wave action and which also seals against the rock to protect from desiccation during low tide. Limpets forage by grazing on algae found on rock surfaces. They scrape films of algae from the rock with a radula, a ribbon-like tongue with rows of teeth. Limpets move by rippling the muscles of their foot in a wave-like motion.

Some limpets have a hole at the top, through which gaseous exchange can occur. Most limpets are less than 3 in (8 cm) long, but a West Mexican Limpet grows to be 8 ins (20 cm).

Contents 1 Homing behaviour 2 Predators and threats 3 Taxonomy 4 References

[edit] Homing behaviour

Some species of limpets return to the same spot on the rock known as a "home scar" just before the tide recedes.^{[citation needed]} In such species, the shape of their shell often grows to precisely match the contours of the rock surrounding the scar. This behaviour presumably allows them to form a better seal to the rock and may help protect from either predation or desiccation. It is still unclear how limpets find their way back to the same spot each time, but it is thought that they follow a mucus trail left as they move. Other species, notably Lottia gigantia seem to "garden" a patch of algae around their home scar. They will aggressively push other organisms out of this patch by ramming with their shell, thereby allowing their patch of algae to grow for their own grazing.

[edit] Predators and threats

Limpets are preyed upon by a variety of organisms including shore-birds and humans. They can be long lived, with tagged specimens surviving for more than 10 years. If the limpet lives on bare rock then it grows at a slower rate but can live for up to 20 years.^{[citation needed]}

Limpets found on sheltered shores (limpets that are less frequently in contact with wave action, and thus less frequently in contact with water) have a greater risk of desiccation due to the effects of sunlight, water evaporation and the wind. To avoid drying out they will clamp to the rock they inhabit, minimizing water-loss from the rim around their base. As this occurs chemicals are released that promote the vertical growth of the limpet's shell.

[edit] Taxonomy

• Suborder Lepetopsina
  • Superfamily Lepetopsoidea
    • Family †Damilinidae
    • Family Lepetopsidae
    • Family Neolepetopsidae
• Suborder Nacellina
  • Superfamily Acmaeoidea
    • Family Acmaeidae
      • Genus Acmaea
      • Genus Notoacmea
      • Genus Pectinodonta
      • Genus Problacmaea
    • Family Lepetidae
    • Family Lottiidae
  • Superfamily Nacelloidea
    • Family Nacellidae
      • Genus Macklintockia
      • Genus Naccula
      • Genus Nacella
• Suborder Patellina
  • Superfamily Patelloidea
    • Family Patellidae
      • Genus Cellana
        • • Species Cellana ampla
          • Species Cellana ardosioea Hombron & Jacquinot, 1841
          • Species Cellana capensis Gmelin, 1791
          • Species Cellana craticulata Suter, 1905
          • Species Cellana conciliata Rainbow limpet
          • Species Cellana denticulata Martyn, 1784
          • Species Cellana eucosmia Pilsbry, 1891
          • Species Cellana exarata Hawaiian blackfoot ‘opihi
          • Species Cellana flava Hutton, 1873
          • Species Cellana grata Gould, 1859
          • Species Cellana melanostoma Pilsbry, 1891
          • Species Cellana nigrolineata Reeve, 1854
          • Species Cellana ornata Dillwyn, 1817
          • Species Cellana radiata
          • Species Cellana rota
          • Species Cellana sandwicensis
          • Species Cellana stellifera Gmelin, 1791
          • Species Cellana strigilis Powell, 1955
          • Species Cellana talcosa Gould, 1846
          • Species Cellana testudinaria Linnaeus, 1758
          • Species Cellana toreuma Reeve, 1855
          • Species Cellana tramoserica Holten, 1802
      • Genus Helcion
        • Subgenus Ansates
          • Species Helcion pellucidus
          • Species Helcion tella
        • Subgenus Helcion
          • Species Helcion pectunculus
        • Subgenus Patinastra
          • Species Helcion dunkeri
          • Species Helcion pruinosus
      • Genus Helioniscus
        • • Species Helcion tella
      • Genus Patella
        • Subgenus Olana
          • Species Patella cochlear
        • Subgenus Patella
          • Species Patella baudonii
          • Species Patella caerulea
          • Species Patella compressa
          • Species Patella depressa
          • Species Patella ferruginea
          • Species Patella gomesi
          • Species Patella lowei
          • Species Patella miniata
          • Species Patella moreleti
          • Species Patella piperata
          • Species Patella rustica
          • Species Patella ulyssiponensis
          • Species Patella variabilis
          • Species Patella vulgata
        • Subgenus Patellida
          • Species Patella granularis
        • Subgenus Patellona
          • Species Patella adansonii
          • Species Patella canescens
          • Species Patella granatina
          • Species Patella lugubris
          • Species Patella oculus
          • Species Patella plumbea
        • Subgenus Scutellastra
          • Species Patella argenvillei
          • Species Patella barbara
          • Species Patella chapmani
          • Species Patella exusta
          • Species Patella flexuosa
          • Species Patella kermadecensis
          • Species Patella laticostata
          • Species Patella longicosta
          • Species Patella peronii
          • Species Patella tabularis
          • Species Patella tucopiana
      • Genus Rhodopetala
        • • Species Rhodopetala rosea

[edit] References

• University of Hawaii Educational page from Christopher F. Bird, Dep't of Botany. Photos and detailed information distinguishing the different varieties.
• Acmaeidae at the NCBI taxonmy website