crayfish dissection

arthropods

arthropods

organisms with an exoskeleton and jointed appendages and the ability to molt, regenerate and undergo metamorphosis

organisms that are considered anthropods

crabs, lobsters, crayfish, spiders, & insects

abdomen

rear section of the body behind the legs.

covered by individual segments, it contains the intestines

cephalothorax

fused front section of the body that includes the head and chest and covers the majority of internal organs

carapace

shell piece covering the front section of the crayfish body

cheliped

large, front claw of the crayfish used for defense and feeding

compound eye

contains many lenses and sees multiple images

telson

center section of the crayfish tail

uropod

side section of the crayfish tail

swimmerete

small legs under the abdomen that are used for swimming and holding the eggs

open circulation

organisms possess a heart but no blood vessels. Organs are bathed in body fluid that flows back into the heart through a hole

anterior

front of the organism

posterior

rear of the organism

exoskeleton

hard covering, without skin, that protects soft insides

spiracles

respiration opening on abdomen of insects

ganglia

nerve clusters

green glands

organ found in the head that gets rid of wastes

mandibles

inside mouth parts

maxilia

middle mouth parts

maxillipeds

outer mouth parts

metamorphosis

change in body form

scavenger

organism that eats everything

crayfish has three teeth in stomach to help chew different types of food.

appendages

extensions on the crayfish body used in moving, sensing, eating and breathing

molting

process of shedding the old, small shell and growing a larger shell

what is the main difference between the cephalothorax and abdomen

the abdomen is flexible and has individual plates while cephalothorax is fused & not flexible

function of the chitinous teeth

shred food

why is it more important for gills to have large surface area

to bring in more O2

what in the human body is the same function as green glands

kidney- excrete wastes

what is the green gland used for and where is it located

green gland is responsible for excretion of wastes

it is in the head

besides swimming what is the swimmerets used for

holding eggs, mating

why is the crayfish classified as segmented animal?

they have separate parts of the body

what parts of crayfish are unlike humans

gills attached to legs

teeth in stomach

green glands in face

open circulatory system

what are the functions of the large pincers

catch prey

defense

why does the crayfish hide after it “molts”

soft body makes them vulnerable

how is crayfish respiratory system dependent on their walking legs

every time they walk they breathe

legs are attached to gills

how many gills does the crayfish have

14 sets

how are the antennae, chelipeds, other walking legs, and swimmerets related?

appendages

what structure are used for capturing prey and securing and eating foods

claws, chelipeds