Presentation on theme: "Sponges, Cnidarians, Flatworms, and Roundworms"— Presentation transcript:
1Sponges, Cnidarians, Flatworms, and Roundworms Chapter 26Sponges, Cnidarians, Flatworms, and Roundworms
2Phylum Porifera (Sponges) Characteristics:Simple body structure with no true tissues; multicellular, (hermaphrodites—animal has both male and female structures), asymmetricalSessile—no movement as adults; are filter feeders (catch food as it floats through them)Have pores that absorb waterSpicules—tiny hard particles of calcium or silicon compounds that make up skeleton
3Phylum Porifera (Sponges) Reproduction: can be asexual (budding) or sexual by releasing sperm that enters other sponges through pores where it will fertilize the egg.After fertilization, larvae will develop. Larvae are immature stages of an animal.
6Review Questions1. What word means that a sponge does not move? Sessile 2. How do sponges eat? By filtering the water around them 3. What tiny, hard particles make up the sponge skeleton? Spicules
7Phylum Cnidaria and Cnetophora CavityBudDiscOuter cell layerJellylike layerInner cell layerTentacleMouthCharacteristicsRadial symmetry with true tissues; cup/bell shapedHave stinging cells called nematocysts to help capture foodSting can be fatal to humansexamples: hydra (very tiny jellyfish-like animal), jellyfish, coral, sea anemonesHas one body opening made of two layers of cells
8Body Form of Cnidarians Has 2 life forms during their life cycle:Polyp- has a tube-shaped body with a mouth surrounded by tentacles.Medusa- has an umbrella-shaped body called a bell.PolypMedusa
9Reproduction in Cnidarians Reproduction: Sexually and asexually through budding
10Review Questions1. What type of symmetry do cnidarians have? Radial 2. What are nematocysts? Stinging cells 3. Give an example of a cnidarian. Coral, jellyfish, sea anemone, hydra 4. What are the 2 life forms of a cnidarian? Polyp & medusa
11Phylum Platyhelminthes “Flatworms” CharacteristicsSimplest animal with bilateral symmetry; have long, thin flat bodies. Usually hermaphroditic.Many are parasitic (ex: tapeworms, liver flukes)
12Phylum Platyhelminthes “Flatworms” ReproductionUsually hermaphroditic and reproduce sexually. During mating, they fertilize each other at the same time.Some can reproduce asexually by regenerating (regrowing) lost parts. (ex: cut planarian: will grow back lost parts!)
14Life Cycle of a Flatworm Adult flukesEmbryosreleasedLarvaSnail hostHumanhost
15Phylum Nematoda “Roundworms” and Rotifera CharacteristicsBilateral symmetry, have both mouth and anusLive in soil, fresh and marine water.Nematodes: roundworms that are often parasiticExamples: Ascaria (intestinal roundworm about 1 ft long), hookworms, trichinella (from undercooked pork), pinworms, heartworms
16Phylum Nematoda “Roundworms” and Rotifera ReproductionMost have separate sexes. Lay eggs.
17FYI: Roundworm parasites of humans Hookworm infections are common in humans in warm climates where they walk on contaminated soil in bare feet.FYI: Roundworm parasites of humansHookworms cause people to feel weak and tired due to blood loss.
18FYI: Roundworm parasites of humans Pinworms are the most common human roundworm parasites in the United States.Pinworms are highly contagious because eggs can survive for up to two weeks on surfaces.
19FYI: AscarisEggs of Ascaris are found in soil and enter a human’s body through the mouth.Ascaris worm coming out of a pig.
20Phylum: ANNELIDA “Segmented worms” Beard wormChristmas tree worm- Also have: (turn to pink sheet)Setae—external bristles for movementCoelom—true fluid-filled body cavityEx: Earthworms, leechesEarthworms loosen soil and make it better for growing plantsReproductionSexual: hermaphrodites (have sperm and eggs), cannot fertilize themselves.Phylum: ANNELIDA “Segmented worms”Description: (PG.16 Purple Sheet)Bilateral symmetry, segmented body, closed circulation (have vessels) and true digestive system, oxygen diffuses through skin
21Phylum: ANNELIDA “Segmented worms” CHARACTERISTICS:Body Temp - EctothermicSymmetry - BilateralDigestive System – CompleteSkeletal System – NoneCirculatory System – ClosedReproductive System –SexualHeart Chambers – Heart BodyEarthwormPhylum: ANNELIDA “Segmented worms”Leeches
22Class Gastropoda (snails & slugs)…2nd largest class after Class Insecta Class Bivalvia “Bivalves” (scallops, oysters, clams, mussels)Class Cephalopoda (squid & octupi)…Only mollusks with brains!Mollusks
23*from Latin word, “molluscus” - soft Phylum: MOLLUSCA*from Latin word, “molluscus” - softDescription:*2ND Largest Phylum of Animals3 Main Body Parts:1. Muscular foot2. Head3. Visceral mass (its insides)FYI: terrestrial and marineReproductionSexual: most have separate sexes, produce gametesGiant clamSea Slug
24Phylum: MOLLUSCA CHARACTERISTICS: Ectothermic Symmetry - Bilateral Digestive System – CompleteSkeletal System – NoneCirculatory System – *OPEN*Reproductive System –SexualNervous System - SimpleHeart Chambers - 2 or 3 in someSquidPhylum: MOLLUSCANautilusoctopus
25Arthropods Subphylum Crustacea (lobsters, crabs, crayfish…GILLS) Class Insecta (all insects have 6 legs)Class Arachnida (spiders & scorpions…all have 8 legs)Class Diplopoda (millipedes)Class Chilopoda (centipedes)Arthropods
26Phylum: ARTHROPODA “Arthropods” CrabsDescription:Have segmented appendages (joints) that allow for flexibilityMolting—since exoskeletons do not grow, arthropods have to shed exoskeleton and form new onePhylum: ARTHROPODA “Arthropods”Bull Ant
27Phylum: ARTHROPODA “Arthropods” CrabsDescription:Mandibles—mouthparts for holding, chewing, sucking, bitingHave segments fused into three main body sections: head, thorax, abdomen; a fusion of the head & thorax = cephalothoraxPhylum: ARTHROPODA “Arthropods”Bull Ant
28Oxygen obtained through: gills, tracheal tubes, or lungs Metamorphosis—series of 4 changes in shape and body structure during development.Incomplete metamorphosis— only has 3 stages; once such an insect hatches, it looks almost like the adult version and is called a nymph
29Many have camouflage to blend in with surroundings
30Body Temp - Ectothermic Symmetry - Bilateral Locust moltingCHARACTERISTICS:Body Temp - EctothermicSymmetry - BilateralDigestive System – CompleteSkeletal System – ExoskeletonCirculatory System – OpenReproductive System –Very diverseNervous System - SimpleHeart Chambers – Muscular Tube“Evil” ButterfliesLobster
32The Arachnids: Ticks & Mites American House Mites
33Egyptian Sea Star Sand Dollars Spiny Cushion Sea StarDescription:Move with tube feet— appendages with suction cups on tipsFYI: Have mouth, stomach, intestines, but no head/brainAll echinoderms have exoskeletons made of calcium carbonate.ReproductionSexually with gametes, asexually with regenerationFeatherStarEgyptian Sea Star Sand Dollars
34Phylum: Echinodermata “Echinoderms” CHARACTERISTICS:Body Temp - EctothermicSymmetry - RadialDigestive System – CompleteSkeletal System – ExoskeletonCirculatory System – OpenReproductive System –Sexual & asexualHeart Chambers – No true heartPhylum: Echinodermata “Echinoderms”