S.M.Joshi College, Hadapsar. Worms Tamboli A.Z. Department of Zoology S.M.Joshi College, Hadapsar. F.Y .B.Sc.

DO NOW Write down your homework Take out your foldable On the back of your foldable answer this question What made scientists put worms in a different category from cnidarians and sponges?

Worms What are the major classifications of worms? Flatworms – Platyhelminthes Roundworms – Nematoda Segmented - Annelida Name 5 characteristics of all worms.  Invertebrates, Long narrow bodies without legs, bilateral symmetry, have tissues, organs, and body systems  How does a worm with both male and female parts usually reproduce? Mating – transfer of sperm  How do worms reproduce asexually?  Can sometimes grow individual worms from pieces

Worms Sense organs, mouth at anterior Long, slender body allows rapid movement / control of direction Three phyla Flatworms - Platyhelminthes Roundworms - Nematoda Segmented worms - Annelida

Characteristics of all worms. Inverts Bilateral symmetry Have a brain Simplest organisms with a brain Cells, Tissues, Organs, and Body Systems Long narrow bodies without legs Reproduce Sexually and Asexually

FAT WORMS - Platyhelminthes What characteristics do all flatworms share? Flat, soft as jelly  What may parasitic flatworms do to their host? Lives inside a host and takes food from it. Give an example of a parasitic flatworm. Tapeworm – absorbs food from the host’s digestive system  Give an example of a free-living flatworm.  Planarian – is free living because it can survive outside its host How do planaria get food? Scavengers – feeding on dead or decaying material. Glides onto its food and inserts a feeding tube. Digestive juices break down food outside of the body. Food is sucked up through this tube, and waste also exits this tube.

Phylum Platyhelminthes: Flatworms planarian Thin (few mm thick) Bilaterally symmetrical Single opening to pass food and waste Pharynx extends out to suck in food Free-living or parasitic Regeneration

Class Turbellaria: Free-living flatworms Marine / freshwater Carnivores or scavengers Light sensitive eyespots Pharynx brings food into gastrovascular cavity Planarian

Class Trematoda: Parasitic flatworms “Flukes” Infect internal organs of host Some live on outside of host

Schistosomiasis --- Blood fluke Affects 200 million people Schistosoma egg in liver

Schistosomiasis larvae Intermediate host Eggs clog blood vessels in liver, spleen, lungs, intestines Intermediate host

Class Cestoda: Tapeworms Parasitic; flat and long Need no digestive system scolex proglottids

Taenia Tapeworms can grow to several meters in length in the intestine

Tapeworm life cycle tapeworm attaches inside host intestine zygotes larval cysts

Roundworms - Nematoda How are roundworms different from cnidarians or flatworms They have a one-way digestive system that is tube like with a mouth and an anus.  Describe the body of a roundworm. Small, have a mouth and anus, many have transparent bodies, round

Phylum Nematoda: Roundworms Free living or parasitic Digestive tract has two openings

Disease- causing roundworms: Trichinella Transmitted by consuming improperly cooked pork Trichinosis Disease caused by trichnella

Disease-causing Roundworms: Elephantiasis Worm infects blood and lymph vessels Transmitted by mosquitoes Tropical parts of Asia Swelling caused by blockage of lymph vessels

Disease-causing Roundworms: Ascaris Parasitic roundworm Affects humans, cats, dogs, horses, pigs, chickens Cause severe malnutrition Spread by eating food or water contaminated with Ascaris eggs Intestine filled with Ascaris

Hook Worms Enter the body through the skin on the soles of the feet Live in the blood and intestines

Hookworms Necator Hookworms penetrate the bottoms of bare feet. Do not go barefoot. This patient presented with a hookworm infection involving the toes of the right foot, which is also known as “ground itch”. Usually the first sign of infection is itching, and a rash at the site where skin touched contaminated soil or sand, which occurs when the larvae penetrate the skin, followed by anemia, abdominal pain, diarrhea, loss of appetite, and weight loss..

Pinworm (Enterobius) 0.5 inches long

Guinea Worms Dracunculus medinensis

Guinea Worms

Segmented Worms - Annelida Describe the body of a segmented worm. Have a mouth and anus that are separated by segments  Name 3 characteristics of all segmented worms. All have a nerve cord, digestive tube, and a closed circulatory system.  What is a closed circulatory system Blood moves within a closed network of tubes called vessels.

Phylum Annelida: Segmented Worms Body divided into segments by internal walls, “septa” In many annelids, segments specialize for specific function: Eyes Antennae Respiration Example: earthworm

Earthworm Over 100 segments Closed circulatory system All fluids contained within small tubes Oxygen enters through skin Gizzard – grinds dirt and soil Setae – bristles that are located on the underside aid in movement Mucus – slippery substance that helps the earthworm move

Aerating the soil

Examples to know: *Phylum Platyhelminthes (flatworms) Planarian, free living Tapeworm, parasitic Flukes: ex. Schistosoma, parasitic, causes Schistosomiasis *Phylum Nematoda (roundworms) Trichinella, parasitic, causes trichinosis filarial worms, parasitic, causes Elephantiasis (filariasis) Ascaris, parasitic hookworms, parasitic pinworms, parasitic Guinea worms, parasitic *Phylum Annelida (segmented worms) earthworm, free living Nereis, free living leech

Closing – Crumble and Toss Get a piece of paper How does the structure of the segmented worm affect its function? Planarian?

Words to know Scissors ( no scapel), forceps, dissecting pins Anterior – Head end Posterior – Butt End Ventral – Stomach side (light color) Dorsal – Back side ( Dark Blood Vessel)

What am I?