Kingdom Animalia Phylum: Annelida

1. Kingdom AnimaliaPhylum: Annelida Pg 672-735

2. P. Annelida- Annelids • 15000, species of segmented worms • Bilaterally symmetrical • True coelom, divided into parts, one segment disabled  other functions • Setae (SEET-ee) external bristles • Parapodia – fleshy protrusions Divide into three classes based on parapodia • Oligochaeta (AHL-uh-goh-KEET-uh) 2. Polychaeta – (PAHL-i-KEE-tuh) 3. Hirudinea- (HIR-yoo-DIN-ee-uh)

3. Class Polychaeta • 2/3 of all annelids are members • Many bristles, help move • They have antennae and mouthparts • Marine habitats • Strong jaws (predators) eat small animals • Feed on sediment as they burrow • Or use tentacles to search ocean floor

4. Class Hirudinea • Smallest class of annelids • 500 species of leeches • Fresh water, moist vegetation on land • No setae or parapodis • Has sucker that attaches to surfaces- movement • Ability to swim • Carnivores, small invertebrates (parasites) • Secret an anesthetic prevents host from feeling • Secret substances that prevents blood clotting • Ingest 10xs its own weight

5. Class Oligochaeta • “few bristles” and few setae on segment • Live in soil or fresh water • Have no parapodia • Earthworm • Adaptations that enable this animal to a burrowing life?

6. Class Oligochaeta cont. • Structure and movement - divided into more than 100 segments - circular and longitudinal muscles - movement possible by segments, slinky 2. Feeding and digestion - ingest soil as they burrow, sucked into mouth by the muscular pharynx passes down the esophagus to the crop to the thick muscular part called the gizzard anus Role is to decompose dead leaves and other organic materials release nutrients into the soil Loosen the soil for plants Allow air to penetrate into the soil

7. Class Oligochaeta cont. 3. circulation- closed system blood goes toward the posterior end by a ventral blood vessel and then to the anterior end by the dorsal blood vessels Five muscle tubes, aortic arches- link the dorsal and ventral blood vessels near the anterior end of the worm

8. Class Oligochaeta cont. 4. Respiration and excretion Gas exchange goes directly through the skin Only if the skin is moist Nephridia-excretory tubules that helps eliminate cellular wastes and excess water Other wastes are released from the body by pores on the ventral surface

9. Class Oligochaeta cont. 5. Neural Control Chain of ganglia connected by the ventral nerve cord Cerebral ganglia- process info from sensory 6. Reproduction- hermaphrodites, but can not fertilize its own egg Mating occurs when two worms press ventral surfaces together with anterior ends pointing in opposite directions, they are held together by the setae and film from clitellum (thick middle) Sperm is secreted in the mucus and is stored in the seminal receptacle to be later used to fertilize the egg Baby takes 2-3 weeks before hatching

10. P. Mollusca- “soft” • Clams, snails, slugs, and octopuses • Soft bodies and hard shells • 112,000 species • Sedentary filer feeders and fast moving predators • Complete nervous system • Coelomates- true coelom (hollow fluid-filled cavity surrounded by mesoderm) • Trochophore- larval stage, free-swimming

11. Body plan Divided into 2 regions: 1. head-foot- 2. visceral mass- contains the heart and organs of digestion, excretion, and reproduction TERMS: Mantle- layer of epidermis that covers the visceral mass, secrets calcium carbonate (shells) Gills- gas exchange Mantle cavity- space between the mantle and visceral mass Do not have segmentated bodies Bilaterally symmetrical Ganglia- cluster of nerve cells Radula- feeding adaptation, flexible tongue like strip of tissue covered with tough, abrasive teeth that point backwards (cut leaves, scrape algae, drill other snails) Use structural differences to divide mollusks into seven classes 1. Gastropoda 2. Bivalvia 3. Cephalopoda

12. Class Gastropoda • “stomach” and “foot” • Largest and most diverse (40,000 species) • Snails, abalones, conchs- single shell • Slugs and nudibranchs- have no shell • Torsion- larval development • Open circulatory system (gills heart tissues)

13. Class Bivalvia • Aquatic mollusks, clams, oysters, scallops • Bivalves- have shells that can be divided in half, connected by a hinge • Adductor muscles are attached to the inside surface of each valve, when it relaxes the valves opens Each valve has 3 layers that are secreted by the mantle 1. thin outer layer- protection from outside environment 2. thick middle layer- strengthen the shell 3. smooth shiny inner layer – protects soft body Sessile and filter feeders (No Radula) Lack a distinct head 3 sets of ganglia: 1. mouth 2. digestive system 3. foot Some have small eyes on mantle edge (sensory structures)

14. Clams- Bivalves • Mud or sand • Siphons- hollow tubes • Cilia on gills – sends water to Incurrent siphon excurrent siphon, water circulates inside clam (trap food) • Separate sexes • Shedding sperm and eggs in water fertilization is external (trochopore)

15. Class Cephalopoda • Octopuses, squids, cuttlefishes, chambered nautiluses • “head-foot” • Free-swimming, predatory • Tentacles- with suction cups • Jaws that look like parrots beak • More advanced nervous system • Closed circulatory system • Male transfers sperm to female mantle cavity with tentacles • Develops from an egg to juvenile (no trochopore) • Chromatophores- dark fluid for distractions

16. P. Echinoderms (spiny skin) • Sea stars, sand dollars, sea urchins, and sea cucumbers • Shallow coastal waters 10,000 m deep • Vary in size • Bright colors • Radially symmetrical • No head or cephalization • Have a bilateral symmetry larva • Deuterostomes – (anus first)

17. 4 major characteristics • Radial symmetry called pentaradial- body parts extend from the center along five spokes • Endoskeleton composed of calcium carbonate plates known as ossicles • Water-vascular system- network of water0filled canals inside their body • Small movable extensions of the water-vascular system called tube feet – they aid in movement, respiration, feeding, excretion

18. Classes • C. Crinoidea- kri-NOYD-ee-uh “lily-like”, sea lilies, feather stars • C. Ophiuroidea- OH-fee-yoor-OYD-ee-uh “snake tail” basket stars and brittle start, largest class • C. Echinoidea – EK-uh- NOYD-ee-uh “spin like” sea urchins and sand dollars, have ridged exoskeleton called a test • C. Holothuroidea- HOH-loh-thuh-ROYD-ee-uh “water polyp” sea cucumbers • C. Asteroides AS-tuh-ROYD-ee-uh “star like” sea star or starfish** economically important because they feed on oysters, clams (human food)

19. Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish • External structure- • composed of several arms (5- 24) • Two rows of tube feet under each arm • Body is flattened • Oral surface- mouth side, under side • Aboral surface – opposite to mouth side • Covered with short spines • Tiny pincers called pedicellariae, keep it free from of foreign objects

20. Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish 2. Water-Vascular System- Net work of water-filled canals that are connected to the tube feet • Water enters through pores in the madreporite (sieve-like plate on aboral surface) • Water passes down the stone canal- tube that connects the madreporite to the ring canal (encircles the mouth) • Radial canal carries water to the tube feet (valves keep it from flowing back up) • Ampulla- sacs on feet contract forcing water into the feet

21. Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish 3. Feeding and digestion a. mouth short esophagus cardiac stomach ( can turn inside out through its mouth when it feeds) pyloric stomach (connects to a pair of digestive glands in each arm) nutrients are absorbed into the coelom by walls of digestive cavity and excess is excreted by anus on aboral surface b. they are carnivores, mollusks, worms

22. Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish 4. Other body systems a. no circulatory, excretory or respiratory organs b. gas exchange and waste excretion by diffusion in walls of tube feet and skin gills c. no head and no brain d. have a nerve ring and radial nerves e. nerve net and touch-sensitive cells

23. Asteroides AS-tuh-ROYD-ee-uh Sea star or star fish 5. Reproduction and development a. separate sexes b. each arm has a pair of ovaries or testes c. 200 million eggs in one year d. external fertilization- e. fee-swimming larva bipinnaria f. 2 months metamorphosis g. regenerate arms, long time

24. P. Arthropoda “jointed foot” • Segmented animals • Appendages • Exoskeleton (protection and support) • High degree of cephalization • Compound eyes- has many light detectors • All have open circulatory system • Molting- sheds its exoskeleton and make a new one • Divided into five subphyla on basis of differences in development and in the structure of appendages • Trilobita 2. Crustacea 3. Chelicerata 4. Myriapoda 5. Hexapoda

25. Subphylum Crustacea • 38,000 known species, vary in size • Ocean, lakes, rivers, and land • Some sessile, some have legs, swim • Have two pairs of antennae • Pair of jawlike chewing mouthparths (mandibles) • Skin to gills for respiration • Embryo becomes a free-swimming larva called a naupius

26. Crayfish • Order Decapods “ten feet” • Have five pairs of legs – locomotin • External structure- a. two major sections- 1. abdomen- 6 segments 2. cephalothorax-head(5)thorax(8) Tagmata- segments fused together to make one larger structure b. antennae- 2 pairs, feelers, taste c. chelipeds- back legs with pinchers d. swimmerets- create water currents and function in reproduction e. telson/uropods- posterior end is paddle like tail

27. Crayfish cont: 2. digestion- esophagus to stomach where teeth grind food into paste and the digestive glands secret enzymes for digestion and absorption extra exits anus 3. respiration- feather like gills, as it walks legs circulate water across gills 4. circulation- open circulatory system

28. Crayfish cont: 5. Excretion- water is removed by excretory organs called the green glands dilute fluids are excreted by a pore at the base of the antennae 6. Neural control/ sensory organs- similar to annelids Have pair of ganglia, sense vibration and chemical in water by sensory hairs, compound eye