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Molluscs - Coggle Diagram
Molluscs
Bivalves
Calcium shell that is bivalved, or in two sections.
Adductor muscles used to close the shell, relax when opening is required. Very strong
Mantle secretes calcium shell, separated into 2 for that bivalved shell.
Filter feeders, use gills and ciliary motion to brush food into oesophagus
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Sessile in most cases, some can move like scallops, muscular foot is inside the shell and not used in locomotion. Instead used to clean the internals from pseudofeces
Gastropods
Helix, in the sense that organs are twisted 180, causes the anus to sit above the mouth on the head of a gastropod
Contains nudibranchs which have lost the ability of shell secretion in the mantle. Possess rhinophores for chemosensory ability
Eyes and stalks, mantle secretes external calcium based shell
Radula on a hard tissue structure, odontophore or something, which forces the radula forward and drags food into the oesophagus, like a tongue. Looks like many barbed ribbon type features.
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Cephalopods
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Jet propulsion, inhalation of water forcefully expelled via muscular contraction of the mantle to move quickly through the water. Fins splay outwards on the mantle for hydrodynamic efficiency
Muscular foot evolved into arms and tentacles. Possess a complex brain, tentacles in octopus possess individual brains.
High evolutionary factors in the cephalopods, from advanced eyes (photoreception, chromatophores)
Mantle does not secrete a shell, some have an internal gladius, some do secrete a shell (nautili) but often non present.
Scaphopods
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No gills, gas diffuses through the mantle. Enters the same way as gases exit.
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Polyplacophores
Plated shells labelled as valve, can be covered by the mantle also referred to as girdle.
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