Simple Animals

Mollusks

Arthropods

Amphibians

Invertebrates with bodies divided into segments

Unsegmented soft bodied creatures with hard shells

Have hard exoskeletons and jointed legs and segmented bodies

Lay eggs in water and can live on land and water
   

Crustaceans

Arachnids

Insects

  
    Hard external shell which protects the body.  The head has antennae and the abdomen has the key organs plus legs for crawling and swimming - many also have claws for crawling and eating Have 8 eyes and 8 appendages, the top 4 for grabbing prey and the bottom for walking.  Spin webs, have no antennae Have 6 legs, and 2 pairs of wings with 3 section bodies, the head, thorax and abdomen.  Also have mandibles and antennae on their heads and also have compound eyes  
         

Reptiles
          [meaning "to creep"] have scales [or modified scales], breathe air, and usually lay eggs and are  cold blooded
salamander vertebrate
tadpole vertebrate
orb snail single shell
gilled snail single shell
pouched snail single shell
freshwater mussel double shell
fingernail clam double shell
crayfish 10 or more legs
fairy shrimp 10 or more legs
isopod aquatic sowbug
backswimmer 3 pairs of legs leathery wings
waterboatman 3 pairs of legs leathery wings
fisherspider 4 pairs of legs
watermite 4 pairs of legs
amphipod or scud 10 or more legs
waterstrider 3 pairs of legs leathery wings
marshtreader 3 pairs of legs leathery wings
giant waterbug 3 pairs of legs leathery wings
water scorpion Rentra 3 pairs of legs leathery wings
water scorpion Nepat 3 pairs of legs leathery wings
caddisfly larva no legs no wings no obvious tail
scavenger beetle 3 pairs of legs hard beetlelike wings
predacious diving beetle 3 pairs of legs hard beetlelike wings
whirligig beetle 3 pairs of legs hard beetlelike wings
crawling water beetle 3 pairs of legs hard beetlelike wings
predacious diving beetle nymph no wings no obvious tail
alderfly nymph no wings no obvious tail
dragonfly nymph no wings no obvious tail
springtail no wings no obvious tail
mayfly nymph no wings 3 tails
mosquito or midge pupa, no legs, has tentacles, brushes or tails
phantom midge, no legs, has tentacles, brushes or tails
soldierfly no legs, has tentacles, brushes or tails
mosquito larva, no legs has tentacles, brushes or tails
damselfly nymph no wings 3 tails
midge larva no legs wormlike
bristleworm no legs wormlike
tubifex worm no legs wormlike
leech no legs wormlike
threadworm no legs wormlike
daphnia waterflea no legs microscopic
copepod cycops no legs microscopic
clamshrimp no legs microscopic
horsehair worm no legs wormlike
planaria no legs wormlike
frog vertebrate amphibian
hydra no legs microscopic
dragonfly nymph eats leeches
leech - great dragonfly nymph food
frog