The largest-bodied freshwater gastropods (adults
usually much greater than 2 cm in shell length) belong
to the related families Viviparidae and Ampullariidae.
The former family, including the common
genera Viviparus and Campeloma, among others,
is distinguished by bearing live young, sometimes
parthenogenically. (Eggs are actually held until
they hatch internally, so the term “ovoviviparous”
is more descriptive.) Viviparids have the ability to
filter feed, in addition to the more usual grazing
and scavenging habit. The Ampullariidae, tropical
or sub-tropical in distribution, includes Pomacea,
which lays its large pink egg mass above the water,
and Marisa, which attaches large gelatinous egg
masses to subsurface vegetation. Ampullariids have
famous appetites for aquatic vegetation. The only
ampullariid native to the U.S.A. is the Florida apple
snail, Pomacea paludosa (Say, 1829), although
other ampullariids have been introduced through
the aquarium trade.
The largest-bodied freshwater gastropods (adultsusually much greater than 2 cm in shell length) belongto the related families Viviparidae and Ampullariidae.The former family, including the commongenera Viviparus and Campeloma, among others,is distinguished by bearing live young, sometimesparthenogenically. (Eggs are actually held untilthey hatch internally, so the term “ovoviviparous”is more descriptive.) Viviparids have the ability tofilter feed, in addition to the more usual grazingand scavenging habit. The Ampullariidae, tropicalor sub-tropical in distribution, includes Pomacea,which lays its large pink egg mass above the water,and Marisa, which attaches large gelatinous eggmasses to subsurface vegetation. Ampullariids havefamous appetites for aquatic vegetation. The onlyampullariid native to the U.S.A. is the Florida applesnail, Pomacea paludosa (Say, 1829), althoughother ampullariids have been introduced throughthe aquarium trade.
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