Studied by 11 people
arthropoda
what phylum are crustaceans in?
80
insects and crustacea make up what percent of animal species
their hard exoskeleton
what are crustaceans names for
2 pairs of antennae
main distinguishing feature of crustaceans
having 2 branches
what does biamous mean?
marine
habitat of most crustaceans
pair of mandibles and 2 pairs maxillae
in addition to antennae what is on the crustacean head?
less
do derived crustaceans have more or less segments than ancestral forms?
crustaceans
closest arthropod relative to insects
genus Calanus
probably the most abundant animals in the world
head, thorax, abdomen
typical major body tagmata
cephalothorax
\n In most crustaceans, one or more thoracic segments are \n fused with the head. What is this segment called?
16-20
how many body segments do current crustaceans have?
carapace
dorsal cuticle found in many crustaceans that may \n cover most of body including thoracic and abdominal segments or just the cephalothorax in some species.
chitin, protein, and calcareous material
what is the cuticle made of?
flexibility
what do joints allow?
telson
end of abdomen ends that bears anus
tergum
Dorsal cuticular plates
pleurites
lateral plates
sternum
ventral plates
dioecious
are most crustacea monoecious or dioecious?
seminal receptacle
where is sperm introduced to females
ventral side of abdomen
where do female crustaceans hold eggs
Hemocoel
major space in arthropods that came from persistent blastocoel which is filled with blood
basis and coxa
two parts of protopods
biamous plan
what basic plan is seen in crayfish appendages?
serial homology
condition where biamous appendages are homologous but may have been modified to have different functions
muscular and nervous
what systems in the thorax and abdomen show segmentation
antagonistic
Most muscles arranged as _________ groups (perform opposite functions) with flexors drawing limb toward the body and extensors straightening a limb out.
open
what type of circulatory system?
1
how many chambers in crustacean heart?
arteries, no veins
do crustaceans have arteries or veins
Hemolymph
name for crustacean blood
pigments
why can hemolymph be different colors
antennal glands
green glands in excretory system
ganglia
Double ventral nerve cord has a pair of ______ for each segment to control appendages, muscles, and other parts
ommatidia
photoreceptor units that make up compound eyes
cornea
covers each eye
facets
small squares and hexagons in cornea called that focus light.
nauplius
Common larval form with uniramous first antennules. First larval form after the egg
exocuticle and endocuticle
what two layers is the procuticle divided into?
endocuticle
dissolved by enzymes during molting
exocuticle and epicuticle
layers of cuticle shed by animal during ecdysis
takes large gulp of water to crack shell at joint
how does an animal break cuticle in ecdysis?
ecdysis
the shedding of the old cuticle
molting
the physiological process of making a larger cuticle
suspension feeding, predation, scavenging
feeding habits found in crustaceans
2
how many parts to a crayfish stomach?
order isopoda
one of the few truly terrestrial crustaceans that also have \n marine and freshwater forms
do not have insect cuticle to conserve water
why must isopods live in moist environments?
photophore
light-producing organ that gives krill bioluminescence
they are external
what is unique about the gills of krill?
order decapoda
Approximately 18,000 species which includes crayfishes, lobsters, crabs, and true shrimp
broader, reduced
Crabs have a __________ cephalothorax and __________ abdomen as compared to crayfish or lobsters.
eyes and statocysts
largest sense organs in crustceans
distal retinal, proximal retinal, reflecting pigment
3 sets of eye pigment cells
ommatidium
optical units made up of the three eye pigments that form the compound eye
monoecious
Barnacles are _________ but generally cross-fertilize
sacs on abdomen
where do most crustaceans brood eggs?
epidermis
what secretes cuticle
intermolt phases or instars
growth phase of molting where animals grow with soft tissue increasing in size until there is no space within the cuticle
premolt phase
molting phase where body fills cuticle and epidermal cells enlarge prior to ecdysis
vasa deferentia
located on the median side at the base of the fifth pair of walking legs in crayfish
oviducts
located on the median side at the base of the third pair of walking legs in crayfish
seminal recepticle
located at the midventral line between fourth and fifth pair of walking legs
Note 
Flashcard (41)