ZOOLOGY PHYLUM PLATYHELMINTHES ANNELIDA and NEMATODA.pdf
- 6. The phylum Platyhelminthes contains over 34,000 animal species. It is difficult to characterize the phylum precisely because of the absence of synapomorphic characteristics.
- 7. Some general characteristics of the phylum Platyhelminthes include the following: • Flat BodyBilateral Symmetry • Single OpeningLack of Respiratory and Circulatory Systems • Nervous System • Mostly Hermaphroditic • Mostly Parasitic • Regeneration
- 9. THE PHYLUM PLATYHELMINTHES IS DIVIDED INTO FOUR CLASSES: 1. Class Turbellaria consist of mostly free-living flatworms 2. Class Monogenea, 3. Class Trematoda, and 4. Class Cestoidea contain species that engage in some form of symbiosis.
- 10. CLASS TURBELLARIA Members of the class Turbellaria are mostly free-living bottom dweller in freshwater and marine environments, where they crawl on stones, sand, or vegetation. Turbellarians are named for the turbulence that their beating cilia create in the water. Turbellarians are predators and scavengers
- 11. Turbe
- 12. The digestive tract of turbellarians is incomplete- it has a mouth opening but lacks an anus. Other turbellarians have digestive tracts that are lobed. The turbellarian pharynx functions as an ingestive organ.
- 13. Triclad Turbellarian Reproductive System. Note that this single individual has both male and female reproductive organs.
- 14. CLASS MONOGENEA Monogenetic flukes are so named because they have only one generation in their life cycle; that is, one adult develops from one egg. Monogeneans are mostly external parasites (ectoparasites) of freshwater and marine fishes, where they attach to the gill filaments and feed on epithelial cells, mucus, or blood.
- 16. CLASS TREMATODA The approximately 10,000 species of parasitic flatworm in the class Trematoda are collectively called flukes, which describes their wide, flat shape. Almost all adult flukes are parasites of vertebrates, whereas immature stages may be found in vertebrates or invertebrates, or encysted on plants. Many species are of great economic and medical importance.
- 19. CLASS CESTOIDEA The most highly specialized class of flatworms are members of the class Cestoidea, commonly called either tapeworms or cestodes.
- 21. . Adult tapeworms range from 1 mm to 25 m in length. Two unique adaptations to a parasitic lifestyle characterize tapeworms: (1) Tapeworms lack a mouth and digestive tract in all of their life- cycle stages; they absorb nutrients directly across their body wall. (2) Most adult tapeworms consist of a long series of repeating units called proglottids. Each proglottids contains one or two complete sets of reproductive structures
- 22. The outer body wall of tapeworms consists of a tegument similar in structure to that of trematodes. It plays a vital role in nutrient absorption because tapeworms have no digestive system. The tegument even absorbs some of the host’s own enzymes to facilitate digestion. With the exception of the reproductive systems, the body systems of tapeworms are reduced in structural complexity.
- 25. Phylum Annelida
- 28. Characteristics of the phylum Annelida include: Body metameric, bilaterally symmetrical, and worm-like Spiral cleavage, trochophore larvae (when larvae are present), and schizocoelous coelom formation Paired, epidermal setae (chaetae) Closed circulatory system Dorsal supra pharyngeal ganglia and ventral nerve cord(s) with ganglia
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- 31. THE
- 32. THE PHYLUM ANNELIDA IS DIVIDED INTO FOUR CLASSES • Class Polychaeta • Class Oligochaeta • Class Hirudinea
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- 34. FIREWORMS They feed on soft and hard coral polyps and small crustaceans.
- 35. Fireworms They feed on soft and hard coral polyps and small crustaceans.
- 36. TUBEWORMS Tube worms live in tubes and are mostly found in the sea.
- 37. BEARD WORMS have long tentacles and live in deep-sea environments
- 38. CLAM WORM It has many small bristles on its body that help it move and dig. Clam worms live in the sea, usually in sand or mud. They can swim and feed on small animals or plants.
- 39. THE
- 40. THE
- 45. THE
- 47. PHYLUM NEMATODA
- 49. Nematodes or roundworms are some of the most abundant animals on the earth-some 5 billion may be in every acre (4,046 m2) of fertile garden soil.
- 50. Many nematodes are parasites of plants or animals; most others are free living in marine, freshwater, or soil habitats. Some nematodes play an important role in recycling nutrients in soils and bottom sediments.
- 51. Characteristics of the phylum Nematoda 1. Triploblastic, bilateral, vermiform (resembling a worm in shape; long and slender), unsegmented, pseudocoelomate 2. Body wall round in cross section with longitudinal muscles only 3. Ecdysis of the collagenous cuticle accompanies growth of juvenile stages 4. Complete digestive tract; mouth usually surrounded by lips bearing sense organs 5. Excretory system usually composed of collecting tubules or renege cells
- 53. Ascaris lumbricoides: Giant Intestinal Roundworm of Humans As many as 800 million people throughout the world may be infected with Ascaris lumbricoides. Adult Ascaris live in the small intestine of humans.
- 54. Enterobius vermicularis (Human Pinworm) Pinworms are small roundworms that are very common in humans. At night, the female pinworms leave the rectum and go to the area around the anus to lay eggs. These eggs cause itching. When someone scratches the itch, the eggs get on their hands or bedclothes. If the eggs are swallowed (for example, by touching the mouth after scratching), they hatch in the stomach. The larvae then move to the small intestine, grow, and eventually make their way to the large intestine. There, the adult pinworms mate, and the females start laying more eggs, repeating the cycle.
- 56. NECATOR AMERICANUS: THE NEW WORLD Hookworm. The adults live in the small intestine, where they hold onto the intestinal wall with teeth and feed on blood and tissue fluids.
- 58. TRICHINELLA SPIRALI: PORKWORM Live in the mucosa of the small intestine of humans and other carnivores and omnivores (e.g., the pig). In the intestine, adult females give birth to young larvae that then enter the circulatory system and are carried to skeletal (striated) muscles of the same host.
- 60. THE FILARIAL WORMS In tropical countries, over 250 million humans are infected with filarial worms. Two examples of human filarial worms are Wuchereria bancrofti and W. malayi. These elongate, threadlike nematodes live in the lymphatic system, where they block the vessels. Because lymphatic vessels return tissue fluids to the circulatory system, when the filiarial nematodes block these vessels, fluids and connective tissue tend to accumulate in peripheral tissues. This fluid and connective tissue accumulation causes the enlargement of various appendages, a condition called elephantiasis.
- 65. PHYLUM PLATYHELMINTHES, PHYLUM ANNELIDA, PHYLUM NEMATODA: LEECHES PHYLUM ANNELIDA FILARIAL WORMS PHYLUM NEMATODA FLATWORMS PHYLUM PLATYHELMINTHES CLASS TUBELLARIA PHYLUM PLATYHELMINTHES
- 66. PHYLUM PLATYHELMINTHES, PHYLUM ANNELIDA, PHYLUM NEMATODA: Class Monogenea PHYLUM PLATYHELMINTHES Class Polychaeta PHYLUM ANNELIDA Class Hirudinea PHYLUM ANNELIDA PORKWORM PHYLUM NEMATODA
- 67. PHYLUM PLATYHELMINTHES, PHYLUM ANNELIDA, PHYLUM NEMATODA: Fireworms PHYLUM ANNELIDA Flukes PHYLUM PLATYHELMINTHES Class Trematoda PHYLUM PLATYHELMINTHES CESTODES PHYLUM PLATYHELMINTHES
- 68. PHYLUM PLATYHELMINTHES, PHYLUM ANNELIDA, PHYLUM NEMATODA: Hookworm PHYLUM NEMATODA Class Oligochaeta PHYLUM ANNELIDA Class Cestoidea PHYLUM PLATYHELMINTHES Filarial worm PHYLUM NEMATODA
- 69. PHYLUM PLATYHELMINTHES, PHYLUM ANNELIDA, PHYLUM NEMATODA: Earthworms PHYLUM ANNELIDA Tubeworms PHYLUM ANNELIDA Pinworm PHYLUM NEMATODA Tapeworms PHYLUM PLATYHELMINTHES
- 70. PHYLUM PLATYHELMINTHES, PHYLUM ANNELIDA, PHYLUM NEMATODA: Fanworms PHYLUM ANNELIDA Beardworms PHYLUM ANNELIDA Round worms PHYLUM NEMATODA Clam worm PHYLUM ANNELIDA
- 71. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 72. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 73. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 74. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 75. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 76. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 77. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 78. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda
- 79. Phylum Platyhelminthes, Phylum Annelida, Phylum Nematoda