After the in-class discussion about body plans, you will use a dichotomous key to identify several organisms to their correct phylum.
Identify each of the following 15 specimens, filling in the requested information in your worksheet:
Animal Body Plans: Specimen 1
Animal Body Plans: Specimen 2
Animal Body Plans: Specimen 3
Animal Body Plans: Specimen 4
Animal Body Plans: Specimen 5
Animal Body Plans: Specimen 6
Animal Body Plans: Specimen 7
Animal Body Plans: Specimen 8
Animal Body Plans: Specimen 9
Animal Body Plans: Specimen 10
Animal Body Plans: Specimen 11
Animal Body Plans: Specimen 12
Animal Body Plans: Specimen 13
Animal Body Plans: Specimen 14
Animal Body Plans: Specimen 15
1
- 1a.
- Has no digestive system or tissues
- loosely organized water-filtering animals
- Special cells: choanocytes
- no apparent symmetry
……………………………………………………………………..Phylum Porifera
- 1b.
- Has a digestive system
- True tissues
- Some body symmetry
…………………………………………………………………..……….. 2
2
2
- 2a.
- Digestive system uses a single opening that serves as both mouth and anus (incomplete or partially complete gut).
………………………………………………………………………………………….. 3
- Digestive system uses a single opening that serves as both mouth and anus (incomplete or partially complete gut).
- 2b.
- Digestive system has mouth and anus as separate openings (complete gut).
…………………………………………………………………………………. 5
- Digestive system has mouth and anus as separate openings (complete gut).
3
3
- 3a.
- Body has circular layout (radially symmetrical)
- Outer ectoderm, inner endoderm (diploblastic).
………………………………………………………….………..…..….. 4
- 3b.
- Body very flat, with mirror-‐image right and left sides (bilaterally symmetrical)
- Has three definite cell layers (triploblastic) but no coelom (acoelomate)
- Flatworms and tapeworms.
………………………………………………………Phylum Platyhelminthes
4
4
- 4a.
- Body has radial symmetry and tentacles with stinging cells (cnidae)
- Planula larva.
……………………………………………………………………Phylum Cnidaria
- 4b.
- Superficially look like jellyfish, but with at most 2 tentacles (biradial symmetry)
- Moves using comb-‐like rows of cilia visible on sides (ctenes)
- No stinging cells, but have cells that produce glue-‐like substance (colloblasts)
- Comb Jellies.
……………………………………………………………..Phylum Ctenophora
5
5
- 5a.
- Body cavity is a pseudocoelom formed by the blastocoel (pseudocoelomates)or there is no body cavity (acoelomate).
……………………….…………….,,………………………….……….. 6
- Body cavity is a pseudocoelom formed by the blastocoel (pseudocoelomates)or there is no body cavity (acoelomate).
- 5b.
- Body cavity is a true coelom lined by mesoderm (coelomates).
………………………………………………..…………………..……… 8
- Body cavity is a true coelom lined by mesoderm (coelomates).
6
6
- 6a.
- Animal doesn’t shed and replace an outer covering as it grows (no ecdysis)
…………………………..………………………………………………..7
- Animal doesn’t shed and replace an outer covering as it grows (no ecdysis)
- 6b.
- Very basic worm shape, often pointed at each end
- Range of sizes, but most are tiny
- Often parasites
- Posses a tough outer cuticle that it sheds and replaces as it grows (ecdysis).
- Roundworms.
………………………………………………………………….. Phylum Nematoda
7
- 7a.
- Tiny, usually in fresh water, commonly with a “wheel organ” of cilia around the mouth
- May be anchored with foot-‐like graspers or swimming
- Rotifers.
………………………………………………………………………Phylum Rotifera
- 7b.
- Worm-‐shaped animals with a unique proboscis housed in a fluid filled chamber (rhynchocoel) that is not part of the digestive tract
- Pilidium larva
- Ribbon Worms.
…………..……………..……………………………Phylum Nemertea
8
8
- 8a.
- Animal develops following the protostome developmental pattern.
……………………………..…………………………………………….. 9
- Animal develops following the protostome developmental pattern.
- 8b.
- Animal develops following the deuterostome developmental pattern.
……………………..………………………………….…………………14
- Animal develops following the deuterostome developmental pattern.
11
9
- 9a.
- Animal has a lophophore.
…………………………………….……..………..…………………….12
- Animal has a lophophore.
- 9b.
- Animal does not have a lophophore.
……………………………………..……….…………………………..10
- Animal does not have a lophophore.
9
10
- 10a.
- Body is segmented.
……………………………………………………………………………11
- Body is segmented.
- 10b.
- Body is not segmented
- Animals posses a radula
- Trochophore larva.
……………………………….…………………….… Phylum Mollusca
10
11
- 11a.
- Body a series of segments, creating a ringed appearance
- Trochophore larva
- Segmented Worms
………………………………………………………………….. Phylum Annelida
- 11b.
- Body segmented with an external skeleton (exoskeleton) and many movable joints
- Exoskeleton periodical shed and replaced during growth (ecdysis)
- Jointed appendages
- Arthropods.
………………………………………………………………. Phylum Arthropoda
12
12
- 12a.
- Animal has a two-‐part shell reminiscent of a clam;
………………………………………………….. Phylum Brachiopoda
- Animal has a two-‐part shell reminiscent of a clam;
- 12b.
- Not as above.
………………………………………………………..……….…………13
- Not as above.
13
13
- 13a.
- Tube dwelling worm-like animal
- Actinotroph larva
……………………………..……..…………….…..Phylum Phoronida
- 13b.
- Animal is colonial usually encased in a hard exoskeleton with pores through which the lophophore extends
- Cyphonautes or coronate larva
…………………………………..…… Phylum Ectoprocta (Bryozoa)
14
14
- 14a.
- Body has five-part, radial symmetry (pentaradial symmetry)
- Unique water vascular system
- Endoskeleton
- Larvae are bilaterally symmetrical
………………………………………………………………….. Phylum Echinodermata
- 14b.
- Bilateral symmetry in adults and larvae
- Notochord, dorsal, hollow nerve cord, pharyngeal slits and muscular post-‐anal tail in life cycle
- Chordates
…………………………………………………………………………… Phylum Chordata