Invertebrates Flashcards
make up about ___ of all animals on earth
97%
many are
aquatic
the simplest of animals
sponges
basal animal
no bilateral symmetry
parazoans
no true tissues
adult sponges are sessile but larvae have
motility (will settle on substrate and grow)
sponges have no
digestive, respiratory, circulatory, reproductive, or nervous systems
sponges reproduce
asexually- through budding
sexual- hermaphroditic, release egg and sperm into the water
annelida
segmented worm- repeated body segments, most advanced worms, complete digestive system, etc.
nematoda
sexually dimrphic worm, pseudocoelomates
platyhelminthes
flat worms
some are free-living, some are parasitic
mollusca
predominately marine, snails clam, octopus
four classes in mollusca
polyplacophora
Gastropoda
Bivalvia
cephalopoda
polyplacophora
chiton- 8 piece shell (valves)
gastropoda
snails, slugs, conchs, nudibranchs
bivalvia
two halves of shell,
clams, oysters, scallops
cephalopoda
octopus, squid, nautilus
cnidaria
jellyfish, sea anemone, corals
primitive nervous system- nerve net
gastrovascular cavity-one opening, serves as both mouth and anus
cnidaria 2 distinct body plans
polyp-sessile
medusa- jellyfish
some display both body plans during the life cycle
anthozoa
corals, sea anemones
polyp body plan
scyophozoa
jellyfish- medusa form is prominent
Arthropoda
jointed legs
dominates the animal kingdom (about 85%)
exoskeleton made of chitin
crustacea
mostly aquatic
gills
covering is carapace
