Mollusca

E17151

Mollusca is a large and diverse phylum of invertebrate animals that includes snails, clams, squids, and octopuses, typically characterized by soft bodies often protected by a hard shell.


Statements (60)
Predicate Object
instanceOf phylum
taxonomic rank
belongsToClade Lophotrochozoa
development many species have a trochophore larval stage
many species have a veliger larval stage
ecologicalRole important filter feeders in aquatic systems
important herbivores in many ecosystems
prey for many marine and terrestrial predators
some species are top predators (cephalopods)
economicImportance source of human food
source of pearls
source of shells for ornament and trade
fossilRecord extends back to the Cambrian period
habitat freshwater environments
marine environments
terrestrial environments
hasApproximateSpeciesCount hundreds of thousands of fossil species
over 80000 described living species
hasCharacteristic body typically divided into head, visceral mass, and muscular foot
cephalopods have a closed circulatory system
coelomate body plan
many forms have a mantle that secretes the shell
many species exhibit torsion during development (in gastropods)
many species have a radula for feeding
many species have complex sensory organs
many species have gills for respiration
most species have a complete digestive tract
most species have a nervous system with paired nerve cords
most species have an open circulatory system
often protected by a calcareous shell
protostome development
soft-bodied animals
some species respire through lungs or body surface
usually unsegmented body
hasCommonName molluscs
mollusks
includesClass Bivalvia
Cephalopoda
Gastropoda
Monoplacophora
Polyplacophora
Scaphopoda
includesRepresentative chitons
clams
cuttlefish
mussels
octopuses
oysters
slugs
snails
squids
isA bilaterian animal group
invertebrate group
isOneOf largest phyla of animals
kingdom Animalia
notableFeature cephalopods exhibit advanced nervous systems and complex behavior
reproduction many species have separate sexes
mostly sexual reproduction
some species are hermaphroditic
taxonRank phylum

Referenced by (6)

Please wait…