Phylum Annelida 1

McDougall ch. 23 annelids video McDougall videos ch 14 symbitotic relationships

Annelids Annelids range in size from the Giant Earthworms, of which Michrochaetus rappi (Michrochaetus michrochaetus) is the largest average length of 1.36 m (54 ins) and a record breaking specimen has been recorded that measured 6.7 metres (22 ft) in length, it was 2cm (0.8 ins) in diametre. The smallest Annelid known to science is Chaetogaster annandalai full grown at 0.5 mm (0.02 ins).

Phylum Annelida From the Latin Annellus a “little ring”. Segmented body Metamere – segment in the body Setae Small hair-like structures Absent in leeches Coelom divided by septa Separating tissue 5

Closed circulatory system Have vessels and a pump Nephridia for each segment (metamere) Excretory structures Nervous system – ganglia = brain; lateral nerve cords Reproduction Most sexual Some hemaphrodites Phylum Annelida

Segmented Worms Body divided into repeating segments 7

Metamerism

Setae – help in movement

ALL SEGMENTED WORMS are EUCOELOMATES! “True coelom” SEGMENTED WORMS (PHYLUM: ANNELIDA) 10

Septa Metamerism 11

Closed Circulatory System 12

Ventral vessel DorsalvesselDorsalvessel BladderBladder NephridioporeNephridiopore NephrostomeNephrostome Metanephridium – excretion of wastes 13

Fig

15 Nervous System

Earthworm Reproduction 16

Trochophore larva Apical tuft MouthMouth AnusAnus Ciliary band StomachStomach 17

Annelid development 18

SEGMENTED WORMS Annelida FREE LIVING PARASITIC Earthworms Leeches 19

Sedentary/Sessile – don’t move 20

Terrestrial Earthworm 21

Feed on Blood Leech 22

Class Polychaeta Many setae Parapodia = “paired feet” 23

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Class Polychaeta Head Parapodium Tentacle 25

JawJaw Everted pharynx EyeEye CirrusCirrus PalpPalp TentacleTentacle ParapodiumParapodium 26 Polychaete Worm Predatory

Nereis 27

Class Polychaeta Fireworm 28

Sedentary Polychaete Lugworm 29

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Pelagic* Polychaete *Drift in the open ocean 32

Just Slinking or Wriggling in the Rain Have you ever noticed that after a spring rain, earthworms come out of the soil and appear on driveways, in puddles, and on sidewalks? Why does this happen? 1. An earthworm breathes through its skin. If its skin dries out, it cannot breathe. Why would an earthworm be more likely to “surface” during the rain than at other times? 2. What types of weather conditions might be fatal for an earthworm?

Class Oligochaeta Few setae Clitellum No parapodia Monoecious Both male and female parts 34

Lumbricus terrestris - earthworm Feed on decaying organic matter Enrich soil Exceedingly important in soil creation, particularly in temperate areas. Without them, agriculture and perhaps the whole of human society as we know it would never have evolved. 35

Return nutrients to soil by decomposing dead leaves and organic matter Burrowing allows air and water to penetrate to roots Tunnels loosen soil so roots can grow more easily Earthworms play an important role in soil fertility “intestines of the earth” -Aristotle 36

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. External Structures of an Earthworm 37

Section 27-3 Anus Clitellum Circular muscle Longitudinal muscle Nephridia Ganglia Ring vessels Reproductive organs Ventral blood vessel Ganglion Brain Mouth Dorsal blood vessel Crop Gizzard Body segments Setae The Anatomy of an Earthworm

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Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Internal Structures of an Earthworm 40

Body wall EpitheliumEpithelium Circular muscle Longitudinal muscle 41

Worms Worms2

Class Hirudinea Anterior & posterior sucker No setae Most live in fresh water Feed Invertebrates Body fluids Blood 43

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PARASITIC SEGMENTED WORMS LEECHES Medical uses 45

Man vs. Wild - Leeches

Annelid Annelid 3 Annelid 4

Dirty Jobs – Bloodworms Dirty Jobs worm grunting part 1 dirty-jobs-shorts-an-introduction-to-worm-grunting- video.htmhttp://videos.howstuffworks.com/discovery/ dirty-jobs-shorts-an-introduction-to-worm-grunting- video.htm Worm grunting part 2 worm-grunting/ worm-grunting/ Earth watch – worm grunting