Family Trochidae - top shells

  Order
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  Class
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Gastropoda
  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
  Aquarium
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  First Fossil Record
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  Remark
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Shell pyramidal, conical to globose in shape, with a moderately large, rounded to angular body whorl and often with a flattened base. Umbilicus more or less narrow to closed, sometimes with a calloused plug. Outer surface smooth or sculptured axially and spirally, with beads, nodules, or tubercles. Periostracum sometimes conspicuous. Aperture rounded to squarish, without a siphonal canal, nacreous inside. Columella and margin of the outer lip generally not in the same plane. Operculum corneous, nearly circular, with many coils and central nucleus. Head with a short snout, a pair of conical, often papillate tentacles and cup-shaped, open eyes on distinct stalks. Foot moderately small, often medially grooved, with a large fleshy ridge on either side bearing sensitive tentaculate processes. Mostly littoral and shallow sublittoral, occurring in large numbers on hard substrates like rocky shores or coral reefs. However, there are also species living among eelgrass or on deep-water bottoms of sand or mud. Slow moving animals, browsing on detritus and algae, sometimes filter-feeding (genus Umbonium). Sexes separate, fertilization external. Eggs laid singly in sea water and hatching as free-swimming planktonic larvae, or bound in gelatinous masses and then frequently hatching as crawling juveniles. Larger or most common species of Trochidae are traditionally used as food by coastal populations in Southeast Asia and oceanic islands of the Southwest Pacific. Shells are utilized by the shellcraft industries, sometimes serving as mother-of-pearl or as lime material (Ref. 349).
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  Division
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  Main Ref
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Ref.
[ e.g. 9948]                       
Glossary
                    [ e.g. cephalopods]


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