4: Mollusca part 1 Flashcards
- second largest animal phylum
- soft-bodied
- eucoelomate
- majority small
Mollusca
contains the feeding (mouth), sensory (photoreceptors), and locomotor organs
head-foot
- contains digestive, circulatory, respiratory, reproductive organs
- found above the foot
visceral mass
mollusca class that has complex eyes
cephalopods
- extendable tonguelike organ
- found in all mollusks except bivalves and most solenogasters
- had filelike teeth made of chitin
radula
supports the radula
odontophore
- adapted for movement or attachment to surfaces
- usually on ventral surface
- movement is typically waves of muscle contraction
foot
foot modifications:
Attachment disc in ___
Hatchet foot in ___
Siphon in ___
limpets; bivalves; cephalopods
- tissue that extends outward from the visceral mass
- secretes the shell
- contains sensory receptors
- capelike; wraps around the body
- where respiratory organs develop from
mantle
- space between the visceral mass and mantle
- houses respiratory organs such as gills and lungs
- digestive, reproductive, excretory system products emptied here
mantle cavity
- secreted by the mantle
- calcium comes from environment
shell
3 layers of shell
- periostracum
- prismatic layer
- nacreous layer
two layers made of calcium carbonate
prismatic and nacreous
periostracum is shell layer made of ___
conchiolin
mollusks 2 kidneys
metanephridia
bivalves and gastropods additional larval stage
- free swimming (some)
- early foot, shell, mantle visible
veliger
8 classes of mollusk
- caudofoveata
- solenogastres
- polyplacophora
- monoplacophora
- gastropoda
- cephalopoda
- bivalvia
- scaphopoda
mollusca class:
- shell-less wormlike animals
- have an oral shield & radula
- dioecious
- resemble the likely common ancestor of all mollusks
caudofoveata
mollusca class:
- similar to caudofoveates
- no radula or gills
- monoecious
- often feed on cnidarians
solenogastres
mollusca class:
- “many plates”
- commonly known as chitons
- dorsoventrally flattened
- dorsal shell made up of 8 plates
- have radula, mostly dioecious, no veliger stage
- head/cephalic sensory organs reduced
polyplacophora
chemoreceptive sense organs found near the anus in polyplacophoras
osphradia
mollusca class:
- “one plate”
- one caplike shell covering the dorsal side
- simple radula
- some organs are serially repeated
monoplacophora
mollusca class:
- “boat feet”
- tusk/tooth shells
- mantle is tube shaped
- single conical shell open on both ends
- lack ctenidia
scaphopoda
where gas exchange occurs through the mantle
ctenidia
