ANNELIDA…The EARTHWORM!

Phylum -Class -

Family -Genus -Species

-

AnnelidaOligochae

taLumbricid

aeLumbricu

sterrestris

PartPart

ProstromiumProstromium

MouthMouth

BrainBrain

PharynxPharynx

EsophagusEsophagus

HeartsHearts

Seminal receptacleSeminal receptacle

Seminal vesiclesSeminal vesicles

FunctionFunction

Digs dirtDigs dirt

Food enters hereFood enters here

Sends/receives nerve Sends/receives nerve messagesmessages

Pushes food alongPushes food along

Brings food to intestineBrings food to intestine

Pumps bloodPumps blood

Holds sperm from another Holds sperm from another wormworm

Makes spermMakes sperm

SystemSystem

DigestiveDigestive

DigestiveDigestive

NervousNervous

DigestiveDigestive

DigestiveDigestive

CirculatoryCirculatory

ReproductiveReproductive

ReproductiveReproductive

PartPart

CropCrop

GizzardGizzard

KidneyKidney

IntestineIntestine

Dorsal Blood VesselDorsal Blood Vessel

Ventral Blood VesselVentral Blood Vessel

Ventral NerveVentral Nerve

ClitellumClitellum

OvariesOvaries

FunctionFunction

Stores foodStores food

Grinding foodGrinding food

Filters blood (wastes)Filters blood (wastes)

Absorbs food into blood Absorbs food into blood (long)(long)

Brings blood forwardBrings blood forward

Blood to posterior Blood to posterior

Connects brain to bodyConnects brain to body

Band making slime to Band making slime to hold eggshold eggs

Make eggsMake eggs

SystemSystem

DigestiveDigestive

DigestiveDigestive

CirculatoryCirculatory

DigestiveDigestive

CirculatoryCirculatory

CirculatoryCirculatory

NervousNervous

ReproductiveReproductive

ReproductiveReproductive

PartPart

SetaeSetae

CuticleCuticle

NephridiumNephridium

FunctionFunction

Bristles for hold in Bristles for hold in burrowburrow

Skin-used to Skin-used to breathe (water)breathe (water)

Removes Liquid Removes Liquid WasteWaste

SystemSystem

MovementMovement

RespirationRespiration

ExcretoryExcretory

Sugar maple forest before earthworm invasion

After earthworm invasionhttp://www.nrri.umn.edu/worms/forest/index.html

3 ecological groups of earthworms

Epigeic example: Lumbricus rubellus (leaf worms)

Endogeic example: Aporrectodea caliginosa (angle worms)

Anecic : Lumbricus terrestris nightcrawlers

7

Body Structure: Coelom

Phylum Annelida8

Digestive System

Phylum Annelida10

Circulatory System Continuous network of

vessels; 5 muscular aortic arches

Dorsal blood-Aortic Arches-Ventral blood

Blood contains hemoglobin, which increases oxygen carrying ability

Phylum Annelida12

Excretory & Nervous System

Nervous system

Phylum Annelida13

Reproduction• Hermaphrodites

• Eggs are produced when two earthworms inseminate each other during mating.

• There are two male openings, and two pairs of small sacs, the sperm receptacles. During mating, these receive sperm from the other partner.

• The eggs, formed in a pair of ovaries, are released from the oviducts into one of two tiny pores

Reproduction continued

• Fertilization can be internal or external

• Breeding is usually seasonal (spring or fall)

• Mating occurs usually when the ground is wet following rain. Earthworms may emerge and travel over the surface of the ground before they mate

Reproduction continued….• The two worms join the lower surfaces of

their anterior ends, with heads pointing in opposite directions. Mucous is secreted until each worm is enclosed in a tube of slime.

• The worms then separate and egg-laying and fertilization occur later.

• Egg-laying starts when the gland cells of the clitellum secrete a mucous ring that is moved forward over the body of the worm

Reproduction continued….

A Worm is Born• Egg cocoons are

deposited in the soil.

• The fertilized eggs develop directly into young worms, which then escape through the egg membrane and an Annelid is born!

Worm Anatomy

External Anatomy:

Internal Anatomy

Please have your Earthworm colorfun and lab on your desk

EXTERNAL Dorsal Anterior Mouth Ventral Posterior Clitellum Setae

INTERNALPharynxEsophagusCropGizzardIntestineDorsal BVAortic archesVentral BVSeminal vesiclesVentral nerve cord

Review your colorfun and be ready to dissect tomorrow!