WORM DISSECTION

KIDSPIRATION by Riedell

CLASSIFICATION Kingdom: Phylum: Class: ANIMALIA Annelida “little rings” OLIGOCHAETA “few bristles”

SETA (plural: setae) BRISTLES on VENTRAL surface http://www.pgjr.alpine.k12.ut.us/science/whitaker/Animal_Kingdom/Earthworm/Earthworm.html

SETAE- Provide traction http://www.greatbluemarble.com/robin_pulling_worm_ground_md_wht.gif http://www.dof.virginia.gov/images/anim-worm-crawl.gif

Segmentation Compartments allow individual parts to move independently Damage insurance If one section is damaged, others can still function http://sps.k12.ar.us/massengale/earthworm_dissection.htm BIODIDAC

Cartoon by: Gary Larson

WHICH END IS WHICH? CLITELLUM = ring Doesn’t go all the way around Image by Riedell/VanderWal©2005 CLITELLUM = ring Doesn’t go all the way around Closest to anterior end Makes mucous for reproduction

2 opening digestive system Image by Riedell/VanderWal©2005 Image by Riedell/VanderWal©2005 MOUTH ANUS Prostomium covers/protects mouth opening senses light/dark, chemicals (food), vibration

EXTERNAL STRUCTURES PROSTOMIUM

EXTERNAL STRUCTURES DORSAL BLOOD VESSEL CAMOUFLAGE http://biog-101-104.bio.cornell.edu/BioG101-104/tutorials/animals/earthworm.html DORSAL BLOOD VESSEL CAMOUFLAGE

CUTICLE (non-cellular protective layer) http://www.flushing.k12.mi.us/srhigh/tippettl/biology/lum/cuticle.html http://www.flushing.k12.mi.us/srhigh/tippettl/biology/lum/cuticle.html

RESPIRATORY No respiratory organs Skin must stay moist for gas exchange Glands produce mucous http://www.wildlifetrust.org.uk/cheshire/IMAGES/watch_earthworm.jpg

SURVIVING HOT DRY CONDITIONS Worms tunnel deeper into the soil Roll into a ball Cover themselves with mucous Slow their body functions down “Suspended animation” = ESTIVATION Wait for conditions to improve http://www.backyardnature.net/earthwrm.htm

SEXUAL REPRODUCTION Earthworms are hermaphrodites HAVE BOTH MALE & FEMALE REPRODUCTIVE ORGANS in same worm

SEXUAL REPRODUCTION OVARIES – make eggs TESTES- make sperm

EXTERNAL STRUCTURES MALE GENITAL PORE- releases sperm to give away http://sps.k12.ar.us/massengale/earthworm_dissection.htm EXTERNAL STRUCTURES MALE GENITAL PORE- releases sperm to give away FEMALE GENITAL PORE- releases eggs OPENINGS to SEMINAL RECEPTACLES- receive sperm from other worms when trade

EXTERNAL STRUCTURES Image by Riedell/VanderWal©2005 SPERM GROOVE- carries sperm from MALE GENITAL PORE down to CLITELLUM

SEXUAL REPRODUCTION Earthworms are HERMAPHRODITES http://upload.wikimedia.org/wikipedia/commons/f/f6/Mating_earthworms.jpg Earthworms are HERMAPHRODITES BUT. . . DON’T fertilize themselves!

SEXUAL REPRODUCTION EXTERNAL FERTILIZATION Produce COCOONS made of MUCOUS and CHITIN (tough carbohydrate)

DIRECT DEVELOPMENT Earthworms produce between 4 - 70 cocoons per year. Animated images from: http://www.urbanext.uiuc.edu/worms/anatomy/anatomy5.html DIRECT DEVELOPMENT Earthworms produce between 4 - 70 cocoons per year. Each cocoon may contain 2-20 embryos. Baby worms hatch after a few weeks http://blogs.salon.com/0003248/images/worm_cocoons.jpg

LOOK INSIDE

COELOM = space around organs Image by Riedell/Vanderwal ©2005

INTERNAL STRUCTURES EUCOELOMATES “true” coelom http://www.biologie.uni-hamburg.de/b-online/library/onlinebio/annelidbodyxs.gif http://www.lander.edu/RSFOX/310images/310bilatImage.html EUCOELOMATES “true” coelom

SEPTUM (pl. SEPTA) Dividing walls separate coelom into compartments Image by Riedell/Vanderwal ©2005 Image from: BIODIDAC

SKELETAL “hydrostatic skeleton” Fluid in coelom protects organs and provides support http://blog.tricerion.com/wp-content/uploads/2010/01/balloon.jpg http://www.wildlifetrust.org.uk/cheshire/IMAGES/watch_earthworm.jpg

EXCRETORY SYSTEM Collect & excrete NITROGEN WASTE Osmoregulation http://www.pleasanton.k12.ca.us/avhsweb/thiel/apbio/review/excretory.html Collect & excrete NITROGEN WASTE Osmoregulation NEPHRIDIUM pl. NEPHRIDIA EXCRETORY TUBULES

INTERNAL STRUCTURES http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb6pg3_files/wormnephridia.jpg

REPRODUCTIVE SYSTEM SEMINAL VESICLES STORE SPERM MADE BY WORM Image by Riedell/Vanderwal©2005 STORE SPERM MADE BY WORM TO “GIVE AWAY” TO OTHERS

REPRODUCTIVE SYSTEM SEMINAL RECEPTACLES Image by Riedell/Vanderwal©2005 SEMINAL RECEPTACLES Store sperm received from other worms during sex

CLOSED circulatory system DORSAL BLOOD VESSEL VENTRAL BLOOD VESSEL

DORSAL BLOOD VESSEL Images by Riedell/VanderWal©2005 Image by Riedell/Vanderwal ©2005

5 AORTIC ARCHES act as “heart” to pump blood Image by Riedell/Vanderwal Image by Riedell/Vanderwal ©2005

Image from: http://www.urbanext.uiuc.edu/worms/anatomy/anatomy6.html

INTERNAL STRUCTURES http://sps.k12.ar.us/massengale/earthworm_dissection.htm

PHARYNX PHARYNX Muscular tube pulls in food Image by Riedell/Vanderwal ©2005 PHARYNX

INTERNAL STRUCTURES CROP-stores food waiting to be digested Image by Riedell/Vanderwal ©2005   CROP-stores food waiting to be digested GIZZARD- grind and mash food

INTESTINE- absorbs nutrients Images by Riedell/Vanderwal ©2005 ADAPTATIONS for getting nutrients out of SOIL 1. REALLY LONG INTESTINE- so food spends long time passing through 2. TYPHLOSOLE- ridge inside increases surface area for more absorption

TYPHLOSOLE Ridge inside intestine increases surface area so more nutrients are absorbed   http://www.uleth.ca/bio/bio1020/images/worm2.jpg TYPHLOSOLE Ridge inside intestine

TYPHLOSOLE inside intestine Image by Riedell/Vanderwal ©2005

Earthworms play an important role in soil fertility "...it may be doubted if there are any other animals which have played such an important part in the history of the world as these lowly organized creatures." ~ Charles Darwin Decompose organic matter (dead leaves, animal waste, etc) Return nutrients to soil Burrowing allows air and water to penetrate to roots Tunnels loosen soil so roots can grow more easily “intestines of the earth” ~ Aristotle http://www.semioticon.com/seo/N/images/niche_3.png

  UNDERNEATH DIGESTIVE SYSTEM VENTRAL NERVE CORD Image by: Riedell/Vanderwal © 2005   UNDERNEATH DIGESTIVE SYSTEM VENTRAL NERVE CORD (nerves usually white) VENTRAL BLOOD VESSEL (usually dark)

REMEMBER embryo orientation is flipped in vertebrates and invertebrates!  Images modified from: http://io.uwinnipeg.ca/~simmons/16cm05/1116/16anim3.htm

BODY PLANS are also flipped! Most INVERTEBRATES have a DORSAL HEART & a VENTRAL NERVE CORD ALL VERTEBRATES have a DORSAL NERVE CORD & a VENTRAL HEART.

If in located in head and acting as “brain” = CEREBRAL GANGLIA GANGLIA= nerve center If in located in head and acting as “brain” = CEREBRAL GANGLIA http://biog-101-104.bio.cornell.edu/BioG101-104/tutorials/animals/earthworm.html

MUSCULAR SYSTEM Image from: http://faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files/Bio%20102/Bio%20102%20lectures/Animal%20Diversity/Protostomes/mollusks.htm#Chelicerates%20(subphylum%20Chelicerata  

Image from: http://www.urbanext.uiuc.edu/worms/anatomy/anatomy8.html