Earthworm Visual Dissection Guide

Illustrated by Veronica Zoeckler

Caudal region - “tail”

Anus Metamere Cranial region - “head” Prostomium

Clitellum

Setae Seminal Mouth receptacle opening

Illustrated by Veronica Zoeckler 1 © 2016 Ward’s Science All Rights Reserved Incisions for Dissection A Lay the worm B Incise beyond the clitellum, C With forceps, grasp the edges dorsal side up. then extend the cut to both of the skin carefully. Pull the Pin the cranial ends, from the middle out. skin back so that it can be and caudal ends. Take great care to cut no pinned down revealing the more than 1/16 of an inch internal anatomy of the deep into the worm. worm. Take care not to tear or pin any internal organs.

Cerebral ganglion

Pharynx

Pharyngeal muscles

Seminal receptacles

Aortic arches

Seminal vesicles

Esophagus

Ovary Oviduct Crop

Gizzard

Dorsal blood vessel

Intestine

Septae

Protonephridia

Ventral blood vessel

Ventral nerve cord

Epidermis Dorsal blood vessel Longitudinal muscles Circular muscles Typhlosole Coelom Intestine

Ventral blood vessel Ventral nerve cord

Setae

Cross Section

Internal Anatomy Cross Section

1. Cerebral ganglion 1. Dorsal blood vessel 2. Pharynx 2. Typhlosole 3. Pharyngeal muscles 3. Circular muscles 4. Seminal receptacles 4. Ventral blood vessel 5. Aortic arches 5. Epidermis 6. Seminal vesicles 6. Longitudinal muscles 7. Esophagus 7. Ventral nerve cord 8. Ovary 8. Intestine 9. Oviduct 9. Coelom 10. Crop 10. Setae 11. Gizzard 12. Septae 13. Intestine 14. Dorsal blood vessel 15. Protonephridia 16. Ventral nerve cord 17. Ventral blood vessel

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ward's+boreal env.lh.indd 2 12/7/2012 9:34:30 AM