Name _________________________________________________________ Period ________ Score __________
Invertebrates Classification Challenge
Most of the things living on this planet are invertebrates, so getting to know a little about them is a good idea.
Invertebrates are members of the Kingdom Animalia, they are linked together by the fact that they have no backbone or
vertebrae. They do not include the Protozoa (single-celled animals) who are generally considered to be part of the
Kingdom Protista.
Instructions: Read the descriptions of each phylum or Class of organism then decide how to classify the individual
organisms shown on the cards. Make a chart with your group placing the organisms where you think they should go. Fill
in your worksheet placing all of the animals in their correct classification grouping. Answer the questions on your
worksheet.
Porifera
Annelida
Nematoda
Cnidaria
Mollusca/Gastropoda
Arthropoda/Insecta
Mollusca/Bivalve
Arthropoda/Arachnid
Mollusca/Cephalopoda
Arthropoda/Crustacea
Platyhelminthes
Echinodermata
Questions:
1. What does Porifera mean? __________________________________________________________
2. What animals belong to phylum Porifera? ______________________________________________
3. Name one characteristic that is unique to phylum Porifera. ________________________________________
4. Where do animals in the phylum Porifera live? ____________________________________________
5. What does Arthropoda mean? _______________________________________________________
6. What animals belong to phylum Arthropoda? ______________________________________________________
___________________________________________________________________________________________
7. Name one characteristic that is unique to phylum Arthropoda. _______________________________________
8. Where do animals in the phylum Arthropoda live? _________________________________________
9. What does Nematoda mean? ____________________________________________________________
10. What animals belong to the phylum Nematoda? ________________________________________________
11. Name one characteristic that is unique to phylum Nematoda. _________________________________________
12. Where do animals in the phylum Nematoda live? ________________________________________
13. What does annelida mean? __________________________________________________
14. What animals belong to the phylum Annelida? ______________________________
15. Name one characteristic that is unique to phylum Annelida. __________________________________________
16. Where do animals in the phylum Annelida live? _____________________________________________
17. What does Mollusca mean? ___________________________________
18. What animals belong to the phylum Mollusca?
______________________________________________________________________________________
19. Name one characteristic that is unique to phylum Mollusca. __________________________________________
20. Where do animals in the phylum Mollusca live? ________________________________________
21. What does Echinodermata mean? ____________________________________
22. What animals belong to the phylum Echinodermata? ____________________________________________
23. Name one characteristic that is unique to phylum Echinodermata. _____________________________________
24. Where do animals in the phylum Echinodermata live? _____________________________________
25. What does Platyhelminthes mean? ____________________________________
26. What animals belong to the phylum Platyhelminthes? ____________________________________________
27. Name one characteristic that is unique to phylum Platyhelminthes. _____________________________________
28. Where do animals in the phylum Platyhelminthes live? _____________________________________
29. What does Cnidaria mean? ____________________________________
30. What animals belong to the phylum Cnidaria? ____________________________________________
31. Name one characteristic that is unique to phylum Cnidaria. __________________________________________
32. Where do animals in the phylum Cnidaria live? _____________________________________________________
Phylum Porifera: from the Latin “porus”
meaning pore and “ferre” meaning to bear
 Sessile and usually spend their lives
anchored to something underwater
 Body wall is made of 2 layers with no
true body cavity
 Are asymmetrical
 Circulate nutrients through pores and
cells
 Simplest animals besides single celled
animals
 The most ancient invertebrates
Phylum Cnidaria: from the Greek “knide”
meaning needle
 Multicellular, few tissues, no organs
 Have radial symmetry
 Have stinging cells
 All live in the water, usually salt water
 Some are sessile and some are sedentary
 Live in aquatic environments, mostly
marine
 Two forms: medusa and polyp
 Most are carnivorous
 All are filter feeders
 Live in the water; mostly salt water
Phylum Platyhelminthes: from the Greek
“platy” meaning flat and “helminthes”
meaning worm
 Some are free-living, some are parasitic
 Have bilateral symmetry
 Are motile or sedentary
 Have eye spots to sense light
 Have 3 body layers with tissues and
organs
 Dorsoventrally flattened
 Live in every habitat (water, land and
parasitic)
Phylum Annelida: From the Latin “annellus”
meaning ringed
 Has 2 or more body layers and a true
coelom
 Have a ventral nerve cord and a simple
circulatory system
 Most are sedentary or motile
 Bilateral Symmetry
 Digestive system with mouth, gut and
anus
 Nervous system
 No true respiratory system
 Closed circulatory system
 Live in soil and water
Phylum Nematoda: from the Greek “nema”
meaning thread and “eidos” meaning form
 Bilateral symmetry
 2 or more cell layers, tissue and organs.
 One-way digestive system with mouth
and anus
 No circulatory system
 Nervous system present
 Live in every habitat (water, land and
parasitic)
Phylum Echinodermata: from the Greek
“echinos” meaning half and “derma” meaning
skin
 Have radial symmetry
 No true body cavity
 More than 2 cell layers, tissues and
organs
 Body shape varies, but has no head
 Have tube feet or feeding tentacles
 Live in all marine environments
 Open circulatory system, simple
nervous system and no excretory organs
Phylum Mollusca: from the Latin
“molluscus” meaning soft body
 Have a true coelom
Phylum Arthropoda: from the Greek
“arthron” meaning joint and “pous” meaning
foot

Bilateral symmetry

2 or more cell layers with tissues and organs

True coelom

Straight gut with anus

3 to 400 pairs of jointed legs

Open circulatory system with hemocoel
(blood-type substance)

Body is divided into 3 or more sections
 Most are motile, some are sedentary

Has an external skeleton
 Live in most environments

Live in every habitat and feed in every way
 Has 2 or more cell layers, tissues and
organs
 Bilaterally symmetrical
 Gills for gas exchange
 Has a pair of kidneys
 Have a circulatory system, digestive
system and a simple nervous system
Class Bivalve: 2 shells
Class Gastropoda: Stomach is used for a
“foot” for locomotion
Class Cephalopoda: “Foot” has evolved into
tentacles
Class insecta: 3 pair of jointed legs and three body
segments
Class Arachnidan: 4 pair of jointed legs, a
cephalothorax and an abdomen are the 2 body
segments
Class Crustacea: many pairs of jointed legs, some for
walking, some for swimming, many body segments