ZOOLOGY STUDY GUIDE - Ye. O. Nevedomska - 2013

LECTURE 1. DIVERSITY OF THE ORGANIC WORLD

4. Zoological Classification

The Kingdom Animalia is classified into two subkingdoms:

✵ Protozoa, or Unicellular organisms (Protozoa);

✵ Metazoa, or Multicellular Organisms (Metazoa).

Subkingdoms are distinguished by fundamental features that are generally non-specific, but rather characteristic of various phyla in different combinations. These features include unicellularity or multicellularity, presence or absence of cellular differentiation, Symmetry types, number of germ layers, Nature of the body cavity, presence and nature of segmentation, and the presence or absence of specific Organ Systems, among others. Specific features are also typically taken into account.

Major phyla of the Animal Kingdom and their species diversity on Earth (based on N. H. Sharova, 2002):

✵ Subkingdom Protozoa, or Unicellular organisms (Protozoa):

1. Phylum Sarcomastigophora (Sarcomastigofora) — 25 thousand species;

2. Phylum Ciliates (Ciliophora) — 7.5 thousand species;

3. Phylum Apicomplexans (Apicomplexa) — 4,800 species;

4. Phylum Microsporidia (Microspora) — 800 species;

5. Phylum Myxozoa (Myxozoa) — 875 species;

6. Phylum Labyrinthomorphs (Labyrinthomorpha) — 35 species;

7. Phylum Ascetospora (Ascetospora) — 30 species.

✵ SUBKINGDOM MULTICELLULAR ORGANISMS (Metazoa):

1. Phylum Placozoa (Placozoa) — 2 species;

2. Phylum Sponges (Porifera) — 5 thousand species;

3. Phylum Coelenterates (Coelenterata) — 10 thousand species;

4. PHYLUM COMB JELLIES (Ctenophora) — 120 species;

5. Phylum Flatworms (Plathelminthes) — 15 thousand species;

6. Phylum Roundworms (Nemathelminthes) — 100 thousand species;

7. Phylum Ribbon worms (Nemertini) — 750 species;

8. Phylum Segmented worms (Annelida) — 12 thousand species;

9. Phylum Mollusca — 113,000 species;

10. Phylum Onychophora — 70 species;

11. Phylum Arthropoda — 1.8 million species;

12. Phylum Pogonophora — 150 species;

13. Phylum Tentaculata — 4,230 species;

14. Phylum Chaetognatha — 120 species;

15. Phylum Echinodermata — 6,000 species;

16. Phylum Hemichordata — 100 species;

17. Phylum Chordata — 51,000 species.