Xenophora pallidula (pallid carrier snail) 3 : 無料・フリー素材/写真
Xenophora pallidula (pallid carrier snail) 3 / James St. John
| ライセンス | クリエイティブ・コモンズ 表示 2.1 |
|---|---|
| 説明 | Xenophora pallidula (Reeve, 1842) - pallid carrier snail from the Philippines. (umbilical view; 12.7 cm across at its widest)The gastropods (snails & slugs) are a group of molluscs that occupy marine, freshwater, and terrestrial environments. Most gastropods have a calcareous external shell (the snails). Some lack a shell completely, or have reduced internal shells (the slugs & sea slugs & pteropods). Most members of the Gastropoda are marine. Most marine snails are herbivores (algae grazers) or predators/carnivores.The xenophorid snails (a.k.a. carrier snails), especially those in the genus Xenophora, are remarkable for their tendency to pick up other shells, skeletal fragments, rocks, or corals (sometimes still alive) from their surrounding environment and cement these objects to their own shells. The result looks like a pile of shells on the seafloor. Often, sponges and serpulid worm tubes are found encrusting the xenophorid shell - they contribute to the illusion that a xenophorid is simply a patch of seafloor. Xenophora carrier snails do this as a camouflage defense against predators. Decorator crabs are arthropods that engage in similar camouflage behavior (storage.montereybayaquarium.org/storage/animals/520x260/d...). Xenophorids are principally detritivores and occur on unconsolidated, fine-grained to coarse-grained to rubbly substrates.In the above photo, numerous attached shells are present. Most of the objects that have been picked up by this individual are shells from other gastropod species, but there are also a few bivalve shells, plus a long worm tube.Classification: Animalia, Mollusca, Gastropoda, Xenophoroidea, Xenophoridae----------------Some info. from Harasewych & Alcosser (1991) and Hill (1996).----------------More info. at:en.wikipedia.org/wiki/Xenophoraanden.wikipedia.org/wiki/Xenophora_pallidula |
| 撮影日 | 2007-07-25 14:45:08 |
| 撮影者 | James St. John |
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