Worm Comparison Chart Colwyn Sleep

Platyhelminthes Nematoda Annelids Flatworms Roundworms Segmented worms Classifications Class Turbellaria: aka “Aschelminthes” Class Polychaeta Predators, scavengers, ¨many bristles¨. -heterotrophic -free-living flatworm Class Oligochaeta -incomplete gut, no includes earthworms. suckers or hooks. Class Hirudinea Class Trematoda: includes leeches. “parasitic worms” -incomplete gut, suckers, outer cuticle.

Class Cestodae: “Parasitic worms” -no gut, suckers and hooks on a scolex -body consists of repeating sections called “proglottids.” Body symmetry and -bilaterally symmetrical. -pseudocoelom -bilaterally symmetrical. characteristics -3 layers of tissues with -body cavity partially -three germ layers organs and organelles. lined with mesoderm. -tube-within-a-tube body -no internal cavity. -tube within a tube body plan, and organs. -nervous system of plan -true coelom and longitudinal fibres rather -complete digestive segmentation. than a net. system -body cavity entirely -Reproduction mostly -unsegmented. lined with mesoderm. sexual as -bilateral symmetry. -the coelom is divided hermaphrodites. -cylindrical shape. into separate -mostly feed on animals -three germ layers. compartments by and other smaller life partitions. These septa forms. enable different -Some species occur in compartments to all major habitats, contract or expand including many as independently. parasites of other animals. -cephalization -body cavity filled with mesoderm. Worm Comparison Chart Colwyn Sleep environment (ie. Class Turbellaria: -live in nearly every Class Polychaeta aquatic, terrestrial) Live in the ocean. Some habitat including soil, -some live in tubes that live in fresh water. salt flats, aquatic may be made of sediments, polar calcium, silica (sand) or Trematoda + Cestoda regions, and the tropics protein Parasitic worms that live -don’t like dry places in the liver, lung, heart, Class Oligochaeta or intestine -live in soil and freshwater, some types are found in the ocean

Class Hirudinea Aquatic, mostly freshwater, some marine varieties.

Nervous system Class Turbellaria: -well developed nervous -chain of ganglia -nervous system is two system comprised of a connected by a ventral lateral nerve cords circum-pharyngeal nerve cord. connected by nerve ring and -most body segments transverse nerves and longitudinal nerves that have a single ganglion. cephalization called a extend down through -also have an anterior “nerve ladder.” the body to the various cerebral ganglia (brain) -cephalization consists parts of the gut and the and respond to light, of a brain, reproductive organs. touch, chemicals, chemosensitive organs, -have several ganglia moisture, temperature, and two eyespots. (groups of nerve cells) and vibrations. -chemosensitive organs in the head region but guide the flatworm no true brain. toward food and the -have simple sense eyespots are sensitive organs. to light. -move away from light likely to avoid predation.

Class Trematoda: -nerve cords and anterior ganglia make up the nervous system.

Class Cestoda No nervous system Worm Comparison Chart Colwyn Sleep

Circulatory system Class Turbellaria: -no true circulatory -consists of a dorsal and -not a true system. system. ventral blood vessel -part of the -do not have an internal with five pairs of gastrovascular cavity. transport system and pseudohearts that -nutrients and gases rely on diffusion. connect the two vessels diffuse directly across together behind the the thin cell layers. head region. -The pseudohearts Class Trematoda + pump the blood toward Class Cestoda: the back of the worm -have no circulatory through the ventral system. blood vessel and blood -absorb nutrients returns through the through the dorsal blood vessel. gastrovascular cavity.

Skeletal system None pseudocoelom acts as Hydroelastic skeleton hydrostatic skeleton. -created by septa, the partitions between segments Digestive system Class Turbellaria: The pseudocoelom is Class Oligochaeta Consists of a single filled with fluid and it -food enters the mouth opening to a distributes digested as they burrow and gastrovascular cavity. A foods and dissolved moves into the pharynx. pharynx sucks up food oxygen to the body. It From the pharynx food from the underside of also acts as hydrostatic moves through the the flatworm. The food skeleton. esophagus to the crop is digested in a where it is stored. It gastrovascular cavity. then passes into the The gastrovascular gizzard where muscles cavity circulates grind it down. The food nutrients to the body. then enters the intestine Wastes are expelled where it is chemically through the same digested and absorbed opening. Nutrients can into the blood stream. be carried through the The intestines have a organism by diffusion typhlosole, which is a because the flatworm is fold that increases so thin. surface area for absorption. Undigested Class Cestoda waste exits the anus. No digestive system Worm Comparison Chart Colwyn Sleep

Movement Class Turbellaria: “Undulatory propulsion” Annelids move via -true system -a hypodermis and a alternating contractions -controlled by layer of longitudinal of circular and longitudinal, circular, muscle, with the high longitudinal muscles. and oblique layers of pressure of the system The circular muscles muscle. produce a whip-like encompass the body -sometimes assisted by wriggle nematodes use wall and contractions secreting a layer of to swim. cause the body to mucus. become long and thin. -some larval stages The longitudinal move using cilia while muscles run the length adults move using of the body and cause muscle contractions. the body to shorten and -nervous system fatten. controls muscles used for movement. Class Oligochaete -made possible by Class Cestoda and segmentation. Class Trematoda: -have circular and No muscular system longitudinal muscles. -the worm anchors middle segments using the setae and contracts circular muscles in front of these segments. -hydrostatic fluid in the coelom increases pressure and elongates the worm. -longitudinal muscles then pull posterior segments forward as they contract and shorten.

Class Polycaeta -have many setae (bristle-like appendages) that help the polychaetes have traction as they move. - In some marine worms they are arranged like a paddle and are called parapodia. Worm Comparison Chart Colwyn Sleep respiratory system Class Turbellaria: -no true respiratory Class Polycaeta (method and Not a true system system. -Parapodia assist in structures) Part of the -breathe through their respiration as annelids gastrovascular cavity. body walls. breath through their Nutrients and gases -pseudocoelom is filled body wall by diffusion diffuse directly across with fluid and it and parapodia expand the thin cell layers. distributes dissolved the surface area of the The gastrovascular oxygen to the body. animal. cavity circulates oxygen -cuticle is permeable to to the body. both water and gases, Class Oligochaeta respiration occurs by -no specialized Class Trematoda: diffusion through it. respiratory organs -no respiratory system -oxygen and carbon as they live in tissues dioxide diffuse through -gas exchange occurs the skin and into small through the blood vessels when the gastrovascular cavity. skin is moist. Excretory system Class Turbellaria: -liquid wastes are excretory system (method and -use specialized cells collected by two tubes consists of nephridia structures) called “flame cells” for and removed from the (filtering organ) in each excretion. These sac- body through an segment like cells beat the water excretory pore. with cilia to keep water -undigested remains are Class Oligochaeta to keep it moving eliminated out of the -a pair of nephridia in through excretory anus. each segment filter the canals and out blood end excrete excretory pores. wastes out the excretory -indigestible wastes pore. leave the same way -cellular wastes and they came in through excess water are mouth. eliminated through nephridia. Class Trematoda: -flame cells for excretion

Class Cestoda No excretory system Worm Comparison Chart Colwyn Sleep

Feeding method and Class Turbellaria -often carnivorous. Class Polychaeta structures -mouth is midway along -some eat decaying -predatory worms have the ventral surface on organic matter, some specialized mouth parts the end of a muscular live on the organic and jaws protrusible pharynx. matter, others eat -tube worms are filter -pharynx pushes food bacteria and fungi. feeders into the gastrovascular -parasitic roundworms cavity. attach to and suck -feed on small animals juices from plants and and the remains of animals. larger dead animals -excrete metabolic waste through their Class Cestoda body walls by diffusion. -absorb food by diffusion through their skin Worm Comparison Chart Colwyn Sleep

Reproduction Class Turbellaria: -separate sexes Class Oligochaeta methods -hermaphrodites, but (dioecous), a few are -hermaphrodites with reproduce via “cross- hermaphroditic. male organs located in fertilization”. Two -the female has long the head and female flatworms align so that coiled ovaries that organs located within they simultaneously produce thousands of the clitellum. fertilize each other. eggs every day. -cross-fertilize by -also capable of -eggs are stored in a aligning head regions regeneration, if cut uterus. with clitellums. lengthwise, a planarian -the vagina leads to an -clitellum secretes a will grow into two external opening. mucus layer to protect separate animals. If cut -the male has one testis sperm as it transfers. down the center, but not that is coiled and -each earthworm injects completely, they will produces sperm. sperm into the mucus develop two heads. -sperm cells pass which moves into a through the sperm duct seminal receptacle Class Cestoda though an opening at -after several days each -carried out by the posterior end of the worm secretes a tube of specialized body worm. mucus and chitin (thick sections called -sperm is released into carbohydrate) which Proglottids. the vagina resulting in picks up the worms -hermaphroditic and can internal fertilization. eggs and stored sperm. fertilize their own eggs. -after fertilization, shell -sperm and egg are -zygotes are passed out glands secrete a shell then expelled through a of host's body with around the egg for slime tube and feces. protection. fertilization takes place. -larvae hatch in water -females lay eggs over -the tube closes up to and in grass. a prolonged time period form a protective case Larvae are eaten by a for 2-3 weeks until the herbivore then burrow young worms hatch. through the wall of the intestine into the blood stream. Intermediate hosts contain tapeworm cysts that when ingested by the final host the cyst hatches out as a scolex which then grows proglottids. Worm Comparison Chart Colwyn Sleep surprising facts Trematode worms Earthworms act as The Phylum name infects snails and decomposers, maintain Annelida means produce mimicry that the fertility of soil, ¨Ringed in Form¨ attracts the bird host. release nutrients into the soil, loosen and A leech can ingest 10 aerate the soil. times its own weight in blood. Once finished eating, a leech will drop off and will not need to eat again for up to a year.