WORMSWORMS

FlatwormsFlatworms

Phylum: PlatyhelminthesPhylum: Platyhelminthes Bilateral symmetryBilateral symmetry CephalizationCephalization Acoelomates-without colelomAcoelomates-without colelom

Speckled FlatwormSpeckled Flatworm

Clings onto lower Clings onto lower rocks.rocks.

Eats amphipods Eats amphipods by engulfing them by engulfing them with mucus and with mucus and swallowing them swallowing them whole!whole!

Blood FlukeBlood Fluke

Form and FunctionForm and Function

Feeding: Feeding: Carnivores, parasiticCarnivores, parasitic Mouth with pharynx (muscular Mouth with pharynx (muscular

tube that moves food and waste)tube that moves food and waste)

Respiration, Circulation, Respiration, Circulation, ExcretionExcretion

Use diffusion for transportUse diffusion for transport Some have flame cells to filter and Some have flame cells to filter and

remove wasteremove waste Many flame cells form tubes that Many flame cells form tubes that

lead to pores on the skinlead to pores on the skin

Response Response

Ganglia for control (nerve cells).Ganglia for control (nerve cells). Eyespot – detect light.Eyespot – detect light. Some have specialized cell to Some have specialized cell to

detect chemicals,food,etc.detect chemicals,food,etc.

MovementMovement

CilliaCillia Muscle cellsMuscle cells

ReproductionReproduction

HermaphroditesHermaphrodites Asexual by fissionAsexual by fission

Groups of FlatwormsGroups of Flatworms

TurbellariansTurbellarians

Free-livingFree-living Marine or fresh Marine or fresh

waterwater

FlukesFlukes

ParasiticParasitic Infect internal Infect internal

organsorgans Blood flukes-Blood flukes-

works its way into works its way into your intestinesyour intestines

Multiple hostMultiple host

Schistosomiasis-Schistosomiasis-fluke eggs clot fluke eggs clot blood vessels, blood vessels, causing swelling causing swelling of tissue.of tissue.

Caused by human Caused by human waste in water waste in water supply.supply.

TapewormsTapeworms

ParasiticParasitic Lives in intestinesLives in intestines Long and flatLong and flat Scolex- suckers or Scolex- suckers or

hookshooks

RoundwormsRoundworms

UnsegmentedUnsegmented Most are Most are

freelivingfreeliving Digestive tract Digestive tract

with two openingswith two openings

Form and Form and FunctionFunction

FeedingFeeding

Most are carnivoresMost are carnivores Use mouth parts and spines to Use mouth parts and spines to

catch foodcatch food Some eat algaeSome eat algae Some are decomposersSome are decomposers

Respiration, Circulation, Respiration, Circulation, ExcretionExcretion

No internal transport- diffusionNo internal transport- diffusion

Response Response

Ganglia from head Ganglia from head Simple structures to detect Simple structures to detect

chemicalschemicals

MovementMovement

Hydrostatic skeletonHydrostatic skeleton Muscles and fluid in the Muscles and fluid in the

pseudocoelom work together to pseudocoelom work together to produce movementproduce movement

ReproductionReproduction

SexuallySexually Internal fertilizationInternal fertilization

Human DiseaseHuman Disease

TrichinosisTrichinosis

Lives in intestines Lives in intestines of mammalsof mammals

1. Females 1. Females burrow into burrow into intestinal wall intestinal wall

2. Eggs into 2. Eggs into larvae travel to larvae travel to organs by organs by bloodstream.bloodstream.

Filarial WormsFilarial Worms

Live in blood Live in blood vesselsvessels

Transmitted by Transmitted by mosquitoesmosquitoes

Can block the Can block the movement of movement of fluidsfluids

ElephantiasisElephantiasis

AscarisAscaris

1. Eggs hatch in 1. Eggs hatch in intestinesintestines

2. Burrow into 2. Burrow into bloodstream to lungsbloodstream to lungs

3. Travel to air 3. Travel to air passages, then passages, then swallowedswallowed

4.Carried to the 4.Carried to the intestinesintestines

AnnelidsAnnelids

Body segmentsBody segments True coelom lined True coelom lined

with mesodermwith mesoderm

Form and FunctionForm and Function

Feeding and digestionFeeding and digestion Filter feeders to predatorsFilter feeders to predators In earthworm pharynx to In earthworm pharynx to

esophagus to crop to gizzard to esophagus to crop to gizzard to intestineintestine

Circulation- closed system, Two Circulation- closed system, Two major blood vesselsmajor blood vessels

Dorsal runs to the head, Ventral to Dorsal runs to the head, Ventral to the tailthe tail

Respiration- Through the skin, gills Respiration- Through the skin, gills in aquatic annelidsin aquatic annelids

Excretion- Nephridia filters fluid in Excretion- Nephridia filters fluid in the coelom, anus for the digestive the coelom, anus for the digestive tracttract

Movement- Hydrostatic, setaeMovement- Hydrostatic, setae Reproduction- Most are sexual, Reproduction- Most are sexual,

HermaphroditesHermaphrodites Clitellum used to form mucus ringClitellum used to form mucus ring

GROUPS OF GROUPS OF ANNELIDSANNELIDS

Oligochaetes- EarthwormsOligochaetes- Earthworms

Hirudinea- LeechesHirudinea- Leeches

PolychaetesPolychaetes

Sandworms, Sandworms, bloodwormsbloodworms

Earthworm Earthworm DissectionDissection

External ViewExternal View

Internal StructureInternal Structure

PharynxPharynx

Aortic ArchesAortic Arches

Seminal VesicleSeminal Vesicle

Seminal ReceptacleSeminal Receptacle

SeptumSeptum

CropCrop

GizzardGizzard

IntestineIntestine

Ventral Nerve CordVentral Nerve Cord

Dorsal Blood VesselDorsal Blood Vessel