Earthworms

Posterior / Tail End Anus Anterior / Head End Clitellum Mouth Setae Seminal Receptacles

Seminal Receptacles Testes Seminal Vesicles Ovaries Ganglia Pharynx Hearts Seminal Receptacles Testes Seminal Vesicles Ovaries Sperm Duct Esophagus Crop Gizzard Intestine Dorsal Blood Vessel Central Nerve Cord Ventral Blood Vessel

Setae Appearance: Tiny bristles (feel them) Location: Entire length of worm. Function: Tiny hairs to help with movement + sex.

Clitellum Appearance: Knob Location: Near center of length. Function: Secretes fluid to enclose fertilized eggs.

Mouth Appearance: Hole Location: Front / Shorter End Function: Food intake/eating

Ganglia/Brain Appearance: Small flesh-colored tissue blob Location: Directly behind mouth. Function: Control organs + responses.

Pharynx Appearance: Round Lump Location: Directly behind mouth + ganglia. Function: Start food break down.

Hearts/Aortic Arches Appearance: Black finger nail clippings Location: Behind Pharynx. Function: Circulate blood.

Esophagus Appearance: Skinny tube Location: Behind Pharynx (center). Function: Carry food to crop + gizzard.

Crop Appearance: Round Lump (feels like a bag) Location: Behind hearts + reproductive organs. Function: Food storage before digestion.

Gizzard Appearance: Round lump (feels muscular) Location: Behind crop. Function: Grind up food.

Intestine Appearance: Long Tube Location: Along back length (leaving gizzard). Function: Absorb nutrients + excrete waste.

Dorsal Blood Vessel Appearance: Thin dark line Location: Along back length (on top). Function: Carry blood.

Ventral Blood Vessel Appearance: Thin dark line Location: Along back length (on bottom). Function: Carry blood.

Seminal Receptacles Appearance: Fleshy colored lumps/bits Location: Behind hearts. Function: Receive sperm for egg fertilization.

Seminal Vesicles Appearance: Small fleshy lumps/bits Location: Behind hearts. Function: Release + store sperm.

Ovaries and Testes Appearance: Small fleshy lumps/bits. Location: Behind hearts. Function: Produce eggs and sperm.

---Dissection Notes--- Lie worm on its belly (rounded/darker side pointed up). Identify clitellum. Carefully cut from MOUTH  CLITELLUM Carefully peel back skin. Identify organs.

Dorsal Blood Vessel (Dark Line) External Dorsal: Mouth Clitellum Dorsal = top (like dorsal fin) more commonly called posterior today. Blood Vessel = carries blood…. Dorsal Blood Vessel (Dark Line) Anus

External Ventral: Mouth Sperm Ducts Clitellum Genital Setae Clitellum: Produces mucus for reproduction Mouth is always closest to clitellum, anus is at the other end. Genital Setae: used to hold the worms together during mating. Sperm Ducts: Produce sperm. Female Genital Pores: contain egg. Worms are hermaphrodites, but only reproduce through sexual reproduction. This allows all worms to reproduce, increasing chance of successful offspring. Sperm Ducts Clitellum Genital Setae Female Genital Pores

Internal: Pharynx Esophagus Ganglia (Brain) Crop Aortic Arches Right Side = Mouth Cut open dorsal side (top) Ganglia = Brain Pharynx = food tube  esophagus Esophagus  food tube  crop (goes underneath the heart and repr. Organs) Crop = storage unit Gizzard = stones + muscle contraction breaks down instestine Intestine = useful nutrients absorbed, waste  out anus Earthworms have 5 aortic arches (5 hearts) Oxygen diffuses directly from air  skin  blood stream Esophagus Ganglia (Brain) Crop Aortic Arches Intestine Gizzard Seminal Vessicles Seminal Recepticles

Internal w/o Digestive… Nerve Cord (Like our Spinal Cord) Seminal Receptacles

Let’s watch a demo… https://www.youtube.com/watch?v=u9HHS1uPFSo