1. Sponges, Cnidarians, Worms, Mollusks 2010 (4 phyla)

2. Sponges & Cnidarians -2010

3. Phylum Porifera (sponges) Yes – they’re animals! -are multicellular, heterotrophic, no cell walls, larva stage is free swimming Movement of water through sponges provides mechanisms for feeding, respiration, circulation, and excretion

4. Sponges are very important in providing habitat in aquatic ecosystems.

6. Cnidarians -Have tissues -Cnidarians are soft-bodied, carnivorous animals -They have tentacles with stinging cells (cnidocytes). -Each cnidocyte has a nematocyst in it which is filled with poison. It’s like a tightly coiled poisonous dart. -Cnidarians have radial symmetry -Cnidarians have two body plans – polyp & medusa

8. Polyp: mouth points up (coral) Medusa: mouth on bottom (jellyfish) Cnidarians reproduce sexually & asexually, depending on the species Corals are important cnidarians as the basis of most marine ecosystems. Many are endangered because of man’s activities.

9. WORMS 2010

12. -WORMS- Earthworms are only one kind of worm – there are 3 phyla of worms. These are the phyla of worms for you to know!!! 1)Flatworms2) Roundworms 3) Annelids These roundworms were passed in the stool of a beagle puppy.

13. Flatworms (Platyhelminthes) Soft, flattened worms that have tissues and internal organ systems. They are the simplest animals to have three embryonic germ layers, bilateral symmetry, and cephalization. –Cephalization: having a head end Have only one body opening (food and wastes go in and out the same opening) Can be free living as carnivores or scavengers Many are parasitic (tapeworms, for example) Eyespots do not “see” but they do sense light

14. Reproduction in flatworms is sexual or asexual –Sexual: most are hermaphrodites. This means they have male and female reproductive organs, but pair up to mate. The worms deliver sperm to each other, which fertilize the eggs in each. –Asexual: by fission –(Some parasitic flatworms have complex life cycles that involve both sexual and asexual reproduction in that life cycle.)

15. Planaria – a common flatworm eyespots

17. Roundworms (Nematodes) Most numerous of all animals Slender, non-segmented, tapering ends Range in size from microscopic to a meter in length Can be free-living or parasitic Habitat ranges from soil, salt-flats, aquatic sediments/water, polar to tropics Have two openings – mouth and anus.

18. Roundworms reproduce sexually and have internal fertilization. Many parasitic roundworms also have very complex life cycles that involve 2-3 hosts or several organs within 1 host Roundworms are responsible for many human diseases including trichinosis, filarial infections causing elephantiasis, ascarid infections, and hookworm infections. These are all very painful and can be fatal.

20. Segmented Worms - Annelids -Annelids are worms with segmented bodies. -Annelids have a true body cavity (makes them more closely related to snails and clams than to flatworms and roundworms) -Range from filter feeders to fierce predators -Many are marine worms that filter their food and don’t much resemble worms as we know them

21. Respiration: Aquatic species breathe with gills. This is the Feather Duster Worm

22. Annelids have a closed circulatory system (blood is contained within a network of blood vessels). The dorsal blood vessel acts like a heart in that is pumps the blood throughout the body. NOTE: Flatworms and roundworms do not have a circulatory system but rely on diffusion to carry nutrients and waste throughout their bodies.

23. Aquatic worms breathe through gills, land- dwelling annelids take in oxygen and give off carbon dioxide through their moist skin. Most annelids reproduce sexually. Some have separate sexes and others are hermaphrodites (like the earthworm) Earthworms are important to ecosystems by borrowing through soil, aerating it, mixing it, and they aid in decomposing dead plant matter. Also their feces helps make soil rich in nitrogen, phosphorus, potassium, micronutrients and beneficial bacteria.

24. Anatomy of an earthworm

25. Mollusca Phylum 2010

26. MOLLUSKS Members of the Mollusca Phylum (mollusks) come in all shapes & sizes, from barely visible with the unaided eye, up to 20 meters long! The name Mollusca comes from the Latin work mollusca, which means “soft”. Mollusks are soft-bodied animals that usually have an internal or external shell.

27. BODY PLAN: Mollusks have 4 parts: 1) Foot- used for crawling, burrowing, and as tentacles for capturing prey 2) Mantle-layer of tissue covering mollusks body (like a cloak) 3) Shell- made of calcium carbonate secreted by glands in the mantle (some mollusks lack shell) 4) Visceral Mass-the internal organs

29. Life cycle Although the Mollusk phylum varies widely, they all share similar developmental stages. Example: Trocophore: larva stage of mollusk. Also is characteristic of the Annelid phylum, which suggests a common ancestor which lived more than 550 million years ago. Trocophore larva MouthStomach Cilia Anus

30. FEEDING IN MOLLUSKS: -Mollusks can be herbivores, carnivores, filter feeders, detritivores, or even parasites. -Most have a radula, which is a flexible tongue-shaped structure used for feeding. The radula has hundreds of tiny teeth attached. Herbiverous mollusks like snails use their radula to scrape algae off rock or to eat soft tissue of plants. Carnivorous mollusks use their radula to drill through shells of other animals, then tear up and swallow the prey’s soft tissue

31. Respiratory System Aquatic mollusks breathe with gills, land snails and slugs breathe using a mantle cavity lined with blood vessels – but must be kept moist for respiration to occur.

32. Circulatory System Mollusks have either open or closed circulatory systems. In an open circulatory system, blood is pumped through vessels by a simple heart, but eventually leaves the vessels and works its way through the different saclike spaces where oxygen and carbon dioxide are exchanged.

33. Reproductive system Mollusks reproduce in a variety of ways. –External fertilization (eggs and sperm are released into the water, eggs are fertilized in the open water. –Internal fertilization –Some are hermaphrodites

34. GROUPS OF MOLLUSKS (You’ll need to recognize at least these 3!!!) 1. GASTROPODS: (means Belly-foot). Shelled or shell-less mollusks that move by using a muscular foot located on the ventral side. –Includes snails, land slugs, & nudibranchs (no shells)

35. 2. Bivalves: (2 halves). These have two shells that are held together by one or two powerful muscles. Are usually sedentary, but can move rapidly by flapping their shells when threatened. These are filter feeders. Includes clams, and 2. Bivalves: (2 halves). These have two shells that are held together by one or two powerful muscles. Are usually sedentary, but can move rapidly by flapping their shells when threatened. These are filter feeders. Includes: Clams Mussels Oyster scallops

36. 3. Cephalopods: (means “head foot”). Soft bodied mollusks in which the head is attached to a single foot, the foot is divided into tentacles or arms. –Most active mollusks –Most have internal shells or no shell at all. Exception is the Nautilus, which has a shell. –These have complex sensory organs and can distinguish shapes by sight and textures by touch.

37. Cephalopods include: Squid, cuttlefish, octopus, nautilus Giant squid Cuttlefish Octopus Nautilus

39. Dorsal (top side) Ventral (bottom side) Anterior (head end) Posterior (tail end) Lateral (side)

40. 1. Name A, B, C, D, & E 2. Draw the moose (or some other animal) and label the dorsal, ventral, lateral, anterior, and posterior views in your notes A B CD E Dorsal Posterior Ventral Lateral Anterior