Answer in 15 minutes

1. Answer in 15 minutes Write true or false (with correct) 1- Metazoa Included Parazoa and metazoa . 2- Metazoa the animals have unicellular body. 3- Eumetazoa have bilateral symmetry only . 4- Parazoa cellular organization . 5- Parazoa are not differentiated cells in layers. 6- Parazoa have true tissues . 7- As example of parazoa are clams . 8- Triploblastic have 2 layers . 9- Eumetazoa divided to triploblastica and uniblastica . 10- Diploblastica have ectoderm , endoderm & mesoderm tissues. 11- Diploblastic have three tissues . 12- Triploblastic is important for movement . 13- Body cavity lying between the body wall and the internal organs . 14- Body cavity may be rich of Mesenchyme cells . 15- Bilateral animals having distinct body cavity . 16- for example of pseudocoelomates Acanthochiton . 17- Mesenchyme cells are occupying the space between the body wall and the anus of the animals . 18- The body cavity derived from the gut of the embryo . 19- This cavity is lined by mesodermal epithelium .

2. Answer in 15 minutes Write true or false (with correct) 20- Ceolom is Internal fluid-filled cavity . 21- Ceolomates have body cavity lined with mesoderm . 22- pseudocoelomates have body cavity partially lined with mesoderm . 23- Schizocoelous are liquid masses of mesoderm split to form the coelomic cavities As the archenteron . 24- Enterocoelous are not mesoderm buds off from the wall of the archenteron and hollows to become the coelomic cavities .

3. Coelomic Invertebrates By Dr. Ola Abu Samak

4. Lecture 2

5. Syllabus • Introduction • Phylum: Annelida (General charactes) • Nereis • Allolobophra caliginosa • Hirudo medicinalis • Phylum: Arthropoda (General charactes) • Astacus fluviatulis & Neptunus pelagious • Daphnia, Cyclops, Balanus • Scolopendra morsitans, Lycosa ferox • Phylum: Mollusca (General characters) • Acanthochiton spinigira, Helix pomatia • Loligo peadlii, Anodonta sp. • Phylum: Echinodermata (General characters) • Astropecten sp.

6. Annelids

7. Aim • What do know about Segmented worms ? • What do know about Segmentation? • What do know about Symmetry? • What do know about Organ Systems ? • What do know about Mechanism/Modeof Locomotion ? • What do know about Typhlosole ? • What do know about Polychaeta ? • What do know about Body wall in Polychaeta ? • What do know about habitat in Polychaeta ? • What do know about Organ Systems in Polychaeta ?

8. Remember

9. Phylum Annelida General characters

10. Phylum Annelida General characters • Segmented worms • 15,000 species • Triploblastic • Protostome • Bilateral symmetry with cephalisation obscured in some species • Internal body space is partitioned ( فصل بحاجز‏ - قسم‏ by septae • Marine, freshwater and terrestrial (in moist soil/humus) species • Cutaneous respiration • Skin is highly vascularised and must stay moist

11. Phylum Annelida General characters Segmentation • is the subdivision of the body into segments • Two advantages result from embryonic segmentation

12. Phylum Annelida General characters Segmentation

13. Phylum Annelida General characters Segmentation • body space is partitioned by septae

14. Phylum Annelida General characters Symmetry

15. Phylum Annelida General characters Symmetry

16. Phylum Annelida General characters systems

17. Phylum Annelida General characters 1- Muscular System 1-Both longitudinal and circular muscle fibers Allows for coordination of propulsive muscular waves in body wall; peristalsis (حركات تقلصية متتابعة فى قناة أو انبوب ( فى الجسم لدفع الغذاء أو الفضلات 2-Special muscles attached to setae to move setae 3- In polychaetes, oblique muscle groups run into the parapodia for movement Mechanism/Mode of Locomotion peristalsis involving the alternating contractions of longitudinal and circular muscle * layers to change the shape of individual segments * Burrowing and creeping using peristalsis and/or parapodia Note

18. Phylum Annelida General characters Integumentary System (skin) • 1- Cellular epidermis that secretes a mucus • 2-Thickened, non-living transparent cuticle • 3-Cilia present in many forms chitinous setae often present; setae absent in leeches; greater number of setae in • 4-As compared to oligochaetes • Allows for coordination of propulsive muscular waves • Coelom is fluid-filled space

19. Phylum Annelida General charactersIntegumentary System (skin)

20. Phylum Annelida General characters Not all organ systems are metameric (ينقسم إلىمفصصات أو أجزاء متماثلة متتابعة علىامتداد الجسم كجسم دودة الأرض) For example: the digestive system extends the length of the organism and is differentiated along its length . Note

21. Phylum Annelida General characters

22. Phylum Annelida General charactersNervous System • 1-Consists of a brain . • 2- cerebral ganglia with two fused ventral nerve cords . • 3- various ganglia similar to arthropods . • (ganglion in each segment (metameric)) • 4- leeches have an anterior brain of six pairs of fused ganglia and a posterior brain of seven pairs of fused ganglia .

23. Phylum Annelida General characters Sensory Organs • sensory tentacles • Palps • Eyespots in polychaetes • (Especially on prostomium)

24. Phylum Annelida General characters Circulatory System • 1- closed circulatory system that is segmentally arranged with aortic arches (“hearts”) • 2- and ventral and dorsal blood vessels surrounding pharynx for circulating blood • 3- blood contains respiratory pigments including hemoglobin • 4-Blood with haemoglobin as O2-carrying molecule

25. Phylum Annelida General characters Respiratory System (gas exchange) • gas exchange by simplediffusion = cutaneousrespiration and/or • Gills in some polychaetes and/or • parapodia in polychaetes act as gills = example of convergent evolution to appendages • and specializedgillsseen inarthropods

26. Phylum Annelida General characters Digestive System (food/water supply) • Complete digestive system with mouth and anus, not segmentally arranged • well muscularized pharynx in oligochaetes • Crop for storage, Gizzard for grinding and Typhlosolewith increase surface area for absorption in oligochaetes • In oligochaetes, ingested soil may contain high levels of calcium; calciferous glands along esophagus secrete calcium ions into gut to reduce calcium ion concentration and maintain acid-base balance in blood

27. Phylum Annelida General characters Digestive System (food/water supply) • In tube worm polychaetes, specialized feathery arms or radioles use ciliary هدبيaction • Mucous to trap food particles of a digestible size • leeches are parasitic, but also predaceous and scavenging تنظيفon fluids and tissues • terrestrial leeches feed on insect larvae, earthworms and slugs

28. Phylum Annelida General characters Digestive System (food/water supply)Typhlosole

29. Phylum Annelida General characters Immune System • Ameobocytes found in blood

30. Phylum Annelida General characters Excretory System • Well developed metanephridia in most segments that involves removal of wastes from the blood and the coelom . • Generally have metanephridia; some have protonephridia each metanephridium has a ciliated funnel or nephrostome that leads by a small ciliated tubule through the septum in to the segment behind to a nephric tubule that empties into a bladder and waste is excreted out a nephridiopore (opening) . • Aquatic annelids secrete ammonia . • Terrestrial oligochaetes secrete less toxic urea . • Osmoregulation occurs via the body surface and the nephridia .

31. Phylum Annelida General characters Reproductive System • -Monoecious in oligochaetes and leeches (Hirudinae) with internal fertilization and direct development (no larval stage = juvenile worms look like mini adults) • -Dioecious (ثنائي البيت اي ان اعضاء التذكير التناسلية في فرد واعضاء التأنيث التناسلية في فرد اخر) in polychaetes with external fertilization and formation of a trochophore larva. -Asexual = most highly organized animals capable of complete regeneration. - This ability varies considerably within the phylum. - Evolutionarily, regenerative capability has been lost in many species. -Both anterior (tail to head) and posterior (head to tail) • -Segment regeneration has been shown in some species.

32. Phylum Annelida General characters Reproductive System • Hermaphrodites - with cross fertilization • Clitellum is a special region at the anterior end of the worm that 1-secretes a mucus cocoon, 2-both during mating (to hold the worms together) 3-protective coat around eggs • Trochophore is typical larval stage

33. Phylum Annelida General characters Major Classes

34. Phylum Annelida General characters Polychaeta • 1- (pol'e-ke'ta) (Gr. polys, many, + chaiti?, long hair). • 2- About 5300 species. • 3- Segmented inside and out; parapodia used in locomotion with many large number of chitinous bristles setae • 4- Distinct head with eyes • 5- palps, and tentacles • 6- No clitellum • 7- Separate sexes • 8- Trochophore larva usually present • 9- Mostly marine. • 10- Examples: Nereis

35. Phylum Annelida General characters Polychaeta • Well - developed head . • *Prostomium is well equipped with sensory and feeding structures . Jaws Teeth Postomial tentachels Peristomial palps Peristomial tentachels

36. Phylum Annelida General characters Polychaeta Body wall • It consists of an outer cuticle which is secreted by :

37. Phylum Annelida General characters Polychaeta • 1- Bristle worms • 2- Mostly marine • 3- Most free-living (living in substrate or free-swimming), but some live in mucus-supported tubes that are surrounded by substrate • 4-Many are active predators, while others are filter feeders

38. Phylum Annelida General characters Polychaeta Habitat • Many crawl on or burrow in the seafloor. • A few drift and swim in the plankton. • Polychaetes include carnivores, scavengers, and planktivores. • The brightly colored fanworms trap planktonon feathery tentacles.

39. Phylum Annelida General characters Polychaeta systems

40. Phylum Annelida General characters Polychaeta Nervous System • 1-dorsal brain • (brain is fund above the pharynx in the head whis is consists of a pair of supra pharynx geal ganglia. • - it is connected with a pair of sub pharyngeal ganglia by acircumpharyngeal commissure on either side which from aring around the pharynx) . • 2- ventral, with a pair of ganglia • 3-solid nerve cord, with ganglia in each segment. • 4-Endocrine- hormones secreted by nervous system. • The brain gives off:- • A- An optic nerve to each eye • B- Palpal nerve to each palpus • C- Atentacular nerve to each group of tentacles. • 5- Three pairs of nerves arise from each of ganglia of the ventral nerve chain • - One pair to 1- the parapodia • 2- the anterior segment • 3- the muscles of the segment

41. Phylum Annelida General characters Polychaeta Nervous System

42. Phylum Annelida General characters Polychaeta Digestive system

43. Phylum Annelida General characters Polychaeta Digestive system • 1- The mouth opens into the pharynx which forms assort of proboscis . • (This is accomplished by protractor and retractor muscles ). • 2- The pharynx leads into a slender esophagus which have digestive gland . • 3 - Straight stomach following the esophagus it extending to the anus .

44. Phylum Annelida General characters Polychaeta Digestive system • Feeding: • Clamworms (Nereis) crawl about on marine surfaces hunting for food using well-developed sensory structures. Once located, prey are seized with chitinous jaws on a rapidly everted, muscular pharynx

45. Phylum Annelida General characters Polychaeta Digestive system • Digestive system • Includes a muscular pharynx that can be everted through the mouth Note

46. Phylum Annelida General characters Polychaeta Circulatory System • Closed system • Use hemoglobin as oxygen carrier.

47. Phylum Annelida General characters Polychaeta Circulatory System • 1- The blood is contained in contractile tube ( the blood vessels ). • 2- There is a dorsal vessel , that lies between the two dorsal longitudinal muscles bands ( which carried blood anteriorly ). • 3- A ventral vessel below the intestine which carries blood posteriorly. • 4- In each segment , the longitudinal vessels are connected on either by right and left transverse vessels to form networks of capillaries in parapodia.

48. Quiz

49. Answer

50. Phylum Annelida General characters Polychaeta Respiratory system • Although many of the smaller polychaetes lack respiratory structures, the larger one do possess gills • Gills are usually modifications of the parapodia