ANIMAL CLASSIFICATION

1. ANIMAL CLASSIFICATION • Systematics or Taxonomy is the study of the kinds and diversity of organisms. • The modern classification is rooted in the work of Karl von Linne (Carolus Linnaeus). • Modern taxonomists use five taxon or more as: Domain, Kingdom Phylum, Class, Order, Family, genus, and species. • Many zoologists recognize three major

2. groups within the animal kingdom: Mesozoa (Phylum Mesozoa), Parazoa (Phylum Porifera), and Eumetazoa (all other phyla). • The Eumetazoa are further subdivided into: protestomes (Platyhelminthes, Nematoda, Mollusca, Annelida, and Arthropoda), and deuterostomes (Echinodermata, Hemichordata, Chordata, and others) • Protozoa 1. Phylum Sarcomastigophora

3. consists of flagellates and amoeba within a single type of nucleus (with over 18,000 described species Characteristics: a) unicellular or colonial b) locomotion by flagella, pseudopodia, or both c) autotrophic (self-nourishing), saprozoic (living in decaying organic matter), or heterotrophic (obtain energy from organic compounds) d) single type of nucleus

4. Euglena Subphylum Mastigophora Class Phytomastigophorea Genus Euglena

5. Euglena • freshwater • contains chloroplast with pyrenoid which • synthesizes and stores polysaccharide • a pigment shield (stigma) permits light to • strike the photoreceptor from only one • direction • haploid and reproduce by longitudinal binary • fission

6. Subphylum Mastigophora Class Zoomastigophorea Genus Trypanosoma

7. Trypanosoma Large and diverse, includes several species that infect wild and domesticated animals in Africa, particularly hoofed animals, and humans. Most of the African trypanosomes are transmitted by vectors, and the most common vector is the tsetse fly (Glossina sp.). The species that cause human African trypanosomiasis ("sleeping sickness") also infect wild animals and can be transmitted from these animals to humans (zoonotic infections). Most African trypanosomes are restricted to Africa, although a few species have been imported into South America.

8. Subphylum Sarcodina Superclass Rhizopoda Class Lobosea Genus Entamoeba histolytica

9. Amoeba (Entamoeba histolytica) • naked • normally found in shallow water • engulf food by phagocytosis • reproduce by binary fission • particle feeders • some are pathogenic line

10. Phylum Porifera - known as sponges; primarily marine • animals consisting of loosely arranged cells • Assymmetrical or radially symmetrical • Three cell types: pinacocytes, mesenchyme cells, • and choanocytes • Central cavity, or a series of branching channels • No tissue or organs Class Calcarea – spicules composed of CaCO3; spicules are needle-shaped and 3 or 4 rays; ascon, leucon or sycon body forms; marine. Ex. Grantia

11. Grantia sp.

12. Class Hexactinellida • Spiculus composed of silica, usually six-rayed; • spicules often fused into an intricate lattice; • cup or vase-shaped; scycon or leucon body form; • Glass sponges. • Ex. Euplectella (Venus flower basket)

13. Euplectella (Venus flower basket)

14. Class Demospongia • Brilliantly covered sponges with needle-shapec or • 4-rayed siliceous spicules or spongin or both; • leucon body form; • Ex. Spongilla, Cliona • Morphology: • Pinacocytes line the outer surface of a sponge • Pinacocyte may be mildly contractile, their combination • may change the shape of some sponges • In some sponges, pinacocytes are specialized into • tubelike, contractile porocytes which regulate • water circulation

15. Below the pinacocyte layer is a jelly-like mesohyl • composed of mesenchyme cells • Mesohyl is specialized for reproduction, secreting skeletal • elements, transporting and storing food and forming • contractile rings around the openings in the sponge • wall. • Below the mesohyl and lining the inner chamber is a layer • of collar cells or choanocytes which are flagellated • cells that have collarlike ring or microvilli surrounding • a flagellum. The flagellum creates water current • through a sponge and the collar filters microscopic food • particles from the water. • Sponges are supported by a skeleton consisting of micro- • scopic needle like spikes called spicules. Made up of • calcium carbonate or silica, spicules are formed by • ameboid cells. Skelton is made up of spongin.

16. Body forms of a sponge • 1) Ascon – vase-like; ostia are the outer opening of porocytes • and lead directly to a chamber called the spongocoel; • choanocytes line the spongocoel. • 2) Sycon – the sponge walls appear folded; water enters • a sycon sponge through openings called dermal pores; • dermal pores are the openings of the incurrent canals • and connect to the radial canals; choanocytes line the • radial canals and the beating of choanocyte flagella • moves water from the ostia through incurrent and • radial canals, to the spongocoel and out the osculum. • 3) Leucon – have an extensively branched canal system; • water enters the sponge through the ostia and moves • to the incurrent canals which lead to choanocyte-lined • chamber; the exit point of water is called oscula.

17. Reproduction Most are monoecious (both sexes occur in the same individual); asexual reproduction involves the formation of gemmules (contain masses of ameboid cells). • Phylum Cnidaria – hydra, anemone, jellyfish, coral • Radial, or biradial symmetry • Diploblastic tissue level organization • Gelatinous mesoglea between the epidermal • and gastrodermal tissue layers • Gastrovascular cavity • Nervous system in the form of a nerve net • Specialized cells called cnidocytes, used in • defense, feeding, and attachement

18. Class Hydrozoa – majority are marine; have colonial polyps in which individuals may be specialized for feeding, producing medusae by budding or defending the colony Ex. Obelia, Hydra Hydra Obelia

19. Class Scyphozoa – “true jellyfish”, all are marine; often deliver dangerous stings; Their primary food include small plankton organisms such as mollusks, rotifers, crustaceans, tunicate larvae, copepods, etc; Ex. Aurelia aurita Aurelia aurita

20. Class Cubozoa – live in warm tropical waters; some possess dangerous nematocyst. Ex. Chironex flecken (sea wasp) Class Anthozoa – marine, colonial, solitary, and lack medusae; Ex. Sea anemone, corals. Corals are invertebrates that are in symbiosis with an algae; they have an alternation of generations during their life cycle (this cycle alternates from a polyp to medusa stage). However, the class anthozoa's medusa stage is absent because they become sessile once they fix themselves in one place. They only move during their developing stages. To obtain food, corals filter feed, feeding on invertebrates and fishes.

21. Corals and Coral reefs

22. Phylum Ctenophora –sea walnuts or comb jellies; marine, • have a spherical form, although several groups • are flattened and/or elongate; bands of cilia called • comb rows are present for locomotion. • Diploblastic tissue-level of organization • Biradial symmetry • Gelatinous mesoglea between the epidermal and • gastrodermal tissue layers • Gastrovascular cavity • Nervous system in the form of a nerve net • Class Tentaculata – with tentacles; Ex. Pleurobranchia • Class Nuda – without tentacles; Ex Beroe

23. Pleurobranchia Beroe

24. Phylum Platyhelminthes – “flatworms” • Usually flattened dorsoventrally, triploblastic, acoelomate, • bilaterally symmetrical, unsegmented worms • Incomplete gut usually present; gut absent in Cestoidea • Cephalization present, with an anterior cerebral ganglion • and usually longitudinal nerve cords • Protonephridia as excretory/osmoregulatory structure • Hermaphroditic, complex reroductive systems

25. Class Turbellaria – mostly free-living and aquatic; predaceous, monoecious with reproductive systems adapted for internal fertilization. Ex. Dugesia Dugesia

26. Class Monogenea – monogenetic flukes; mostly ectoparasites on vertebrates; Ex.

27. Class Trematoda – all are parasitic; several holdfast devices present; gut is present and most are monoecious Ex. Paragonimus westermani

28. Class Cestoidea – are tapeworms and gut parasites of vertebrates; structurally more specialized than the flukes, having scolex and attachment organs, a neck region, and a strobila which consists of a chain of segment; gut is absent and the reproductive system is repeated in each proglottid. Tapeworm

29. Phylum Nemertea – elongate flattened worms found in marine • and sand, are called “proboscis worms” because they • have long proboscis. • Triploblastic, acoelomate, bilaterally symmetrical • unsegmented worm, possessing a ciliated epidermis • containing mucous gland • Complete digestive tract and with an anus • Protonephridia present • Cerebral ganglion, longitudinal nerve cords, and • transverse commissures • Closed circulatory system • Body musculature organized into 2 or 3 layers • Dioecious

30. Nemertes

31. Phylum Gastrotrichia – microscopic aquatic animals with a head, neck, and trunk; numerous adhesive glands are present; hermaphroditic; parthenogenesis is common in freshwater species.

32. Phylum Rotifera – small animals, abundant in freshwater habitats; ciliated “corona” in the anterior region of the body; triploblastic, bilateral unsegmented, complete digestive system; body covered by a cuticle called “lorica”; feed on plankton organisms; reproduce by parthenogenesis. Brachionus

33. Phylum Kinorhyncha – minute worms living in marine habitats bodies composed of 13 or 14 zomites, which have cuticular scales, plates, spines. Ex. Echinoderes Echinoderes

34. Phylum Nematoda – roundworms, triploblastic, bilateral vermiform; unsegmented, pseudocoelomate; complete digestive tract; live in aquatic and terrestrial environments; many are parasitic and of medicinal and agricultural importance. Ex. Ascaris lumbricoides (intestinal round- worm), Trichinella spiralis (porkworm) Ascaris lumbricoides

35. Phylum Nematomorpha – elongate worms commonly called horsehair worms or Gordian worms Phylum Acantocephala – “spiny-headed worms” because of their spiny proboscis; endoparasites in vertebrates Phylum Loricifera – microscopic animals which have spiny head and thorax; live in gravel and marine environments; Ex. Nanaloricus mysticus Phylum Priapulida – cucumber-shaped, wormlike animals; live buried in the sand and mud in marine habitats; Ex. Priapulus caudatus

36. Phylum Mollusca – soft-bodied animals Body of 2 parts: head-foot and visceral mass Mantle that secretes a calcareous shell and covers the visceral mass Mantle cavity functions in excretion, gas exchange, elimination of digestive wastes, and release of reproductive products Protostome characteristics, including trochophore larvae, spiral cleavage, and schizocoeleous coelom formation Coelom reduced to cavities surrounding the heart, nephridia, and gonads Open circulatory system in all but one class (Cephalopoda) Radula usually present and used in scraping food

37. Class Bivalvia – bivalves such as mussels and clams; Ex. Mytilus Class Gastropoda – Snails and coiled shells; Ex. Nerita Class Cephalopoda – squids and octopus; foot modified into a circle of tentacles and a siphon; Ex. Octopus, Loligo, Nautilus

38. Phylum Annelida – segmented worms; triploblastic, coelomate animals, shows metamerism, have complete digestive tract Class Polychaeta – “tubeworms”; predators, scavengers, or filter-feeders; mostly marine and possess parapodia with numerous setae. Ex. Nereis, Sabella Class Oligochaeta – “earthworms”; includes primarily freshwater and terrestrial annelids; possess few setae, lack head and parapodia; scavengers; Ex. Tubifex Class Hirudinea – “leeches”; complex arrangement of body-wall muscles, and the loss of septa influence patterns of locomotion; predatory and feed on body fluids, such as blood of vertebrates Ex. Hirudo

40. Phylum Arthropoda – “jointed legs” animals • Metamerism modified by the specialization of body • region for specific functions (tagmatization) • Chitinous exoskeleton • Paired, jointed appendages • Growth is accompanied by ecdysis or molting • Ventral nervous system • Coelom reduced to cavities surrounding gonads and • excretory organs • Open circulatory system • Complete digestive tract • Metamorphosis often present

41. Subphylum Trilobitomorpha Subphylum Chelicerata Class Arachnida – spiders, mites, ticks, scorpions Subphylum Crustacea – mostly aquatic; head with 2 pairs of antenna, I pair of mandible, 2 pairs of appendages; biramous appendage Class Branchiopoda – “water fleas” Class Malacostraca – lobsters, crayfish, crabs, shrimps Class Cirripedia – barnacles Class Copepoda – copepods Subphylum Uniramia Class Hexapoda - with three pairs of legs; usually two pairs of wings; with body, head, thorax and abdomen; insects

42. Phylum Echinodermata – postradial symmetry; have an endoskeleton of interlocking calcium carbonate and ossicles; have a water vascular system that is used for locomotion, food gathering, attachment, and exchanges with the environment Class Asteroidea – sea stars Class Ophiuroidea – brittle stars and basket stars Class Echinoidea – sea urchins, heart urchins, sand dollars Class Holothuroidea – sea cucmbers

43. Phylum Hemichordata – live on marine sediments; includes the acorn worms and the pterobranchs Ex. Balanoglossus Phylum Chordata – marine, freshwater and terrestrial habitats; a notochord, pharyngeal slits, a dorsal tubular nerve cord, and a post anal tail are all present at some time in life histories Subphylum Urochordata- sea quirts, tunicates Subphylum Cephalochoradata – Amphioxus Subphylum Vertebrata – lampreys, hagfishes, sharls, bony fishes, frogs, reptiles, birds, mammals