lecture 16- bivalve Flashcards
what clade is bivalve
conchifera
what is class bivalve
mussels and oysters and clams and shit
how many spp bivalve
10000
habitat of bivalves
most marine some freshwater
What are bivalves modified for?
burrowing and feeding on fine particles
what is a bivalve shell
two valves hinged dorsally and kept aligned with hinge teeth.
What keeps valves closed
adductor muscles
what are some adaptations of bivalves
bivalve shell
loss of radula
byssus
lateral compression of body
adductor muscles
ligament w hinge of shell
bivalve features
Head
Ctenidia
Foot
Mantle
-head very reduced and lacks radula
-ctenidia modified for filter feeding
-produce byssal threads
-foot modified for burrowing
-mantle ofter modified into siphons
what is weird about scallop mantle
they have eyes in their mantle
juvenile shell
umbo
where is the hinge ligament in respect to umbo
posterior
what happens to the ligament when the adductor muscles contract
the valve closes and the outer part of ligament is stretched and inner part is compressed
what is contained in the hinge area
teeth
what do the teeth do
keep shell from slipping
how many ctenidia do bivalves have
one pair
different types of ctenidia
respiratory ctenidia and filter feeding ctenidia
what are respiratory ctenidia called
protobranch gills
what are filter feeding ctenidia called
lamellibranch gills
lamellibranch gills morphology
filaments arranged in Vs of ascending and descending arms called demibranches
what is the mantle cavity divided into in lamellibranch gills
an exhalent and inhalent chamber
what are the two types of lamellibranch gills
filibranch and eulamellibranch
filibranch gills
adjacent gill filaments attached by tufts of cilia
eulamellibranch gills
adjacent gill filaments attached by bridges of solid tissue
