1. Phylum Annelida the segmented worms
1st phyla we will talk about and what we will cover in the lab today is…
the segmented worms

2. Activities and Assignments
Labs
Earthworm behavior (binder)
Earthworm Dissection (binder)
Video Med. Uses of Leeches (binder)
Quiz- short topic
Text Reading
Worksheet
Vocabulary: monecious, dioecious, mutualism, tagmosis, detritus, triploblastic, coelom, septa, cerebral ganglia, parapodia, setae, parts of the worm anatomy from the lab

3. How do the Annelids fit in?
Annelida
Rotifera
Nematoda
Platyhelminthes
Nemertea
Cnidaria
Porifera
unknown
common ancestor

4. Annelida Characteristics
Triploblastic (3 tissue layers)
Organ level of organization
Bilateral Symmetry
Cephalization
Coelomate (with a body cavity)

5. Remember these ideas from the last chapter

6. Coelomate
Have a “true” body cavity that is completely surrounded by mesoderm
ectoderm
coelom
mesoderm
Gut
endoderm

7. Annelid Characteristics
the coelom
is a closed, fluid filled cavity that surrounds the gut
the fluid within acts as a circulatory system and hydroskeleton
mesodermal membranes (mesenteries) suspend organs in the coelom
ectoderm

8. Annelida Characteristics
Metamerism
The body is made up of serially repeating, coordinated segments called metameres that are separated from one another by septa.
Each metamere contains sets of repeating organs
e.g. gut, blood vessels, nerve cord, excretory organs

9. Metamerism
septa
Think of a row of tires

10. Annelida Characteristics
Nervous system
2 cerebral ganglia
a ventral nerve cord with 2 ganglia per metamere.
In some species, sensory organs such as eyes, palps, and tentacles have arisen

11. brain
nerve cord
2 cerebral ganglia

12. Annelida Characteristics
Arthropod exoskeleton component
Locomotion
both longitudinal and circular muscles
most have setae (chitonous bristles secreted by the epidermis) that aid in locomotion and burrowing
Skeletal System
fluid in coelom acts as a hydrostatic skeleton

13. Class Oligochaeta Locomotion Circular muscle contraction
Longitudinal muscle contraction

14. Annelind Cross section

15. Annelind Cross section
Circular muscle
Longitudinal muscle
skin

16. Annelind Cross section
coelom
Circular muscle
Gut (intestine)
Longitudinal muscle
Intestine wall
skin

18. Annelid Characteristics
Gas exchange
mainly by diffusion
Class Polychaeta often has specialized structures for gas exchange
(e.g. parapodia, gills)

19. Annelid Characteristics
Digestive System
You’ll get to observe these more closely during the dissection
complete
regional specialization
Circulatory System
closed circulatory system composed of blood vessels (some of which are contractile and act as “hearts”)
some circulation is also accomplished by the coelomic fluid

20. This diagram is found in the dissection lab
coelomic chambers
pharynx
mouth
esophagus
crop (storage)
gizzard (mashing)
This diagram is found in the dissection lab

21. More properly called “aortic arches”
One each on the dorsal and ventral sides
hearts
blood vessels

23. Annelid Characteristics
Excretion
excretion is accomplished by organs called nephridia (singular nephridium) in the skin
sexual
Hermaphrodites (individuals with both sets of reproductive organs)
Reproduction

25. Phylum Annelida
Class Oligochaeta
Class Hirudinea
Class Polychaeta

26. Class Oligochaeta
1st phyla we will talk about and what we will cover in the lab today is…

27. Class Oligochaeta terrestrial, freshwater and marine
have few setae (Oligo = few, chaeta = setae)
usually feed on detritus
(decaying organic matter)
have specialized digestive system to obtain the maximum amount of nutrients out of the detritus (e.g. pharynx, gizzard, crop…)

28. Class Oligochaeta Locomotion Circular muscle contraction
Longitudinal muscle contraction

29. Class Oligochaeta Reproduction usually monoecious cross-fertilize by
exchanging sperm
clitellum
testis

30. Ecology Earthworms are essential soil aerators
If all the material ever moved through earthworms was piled up, the heap would rise 30miles , more than 5 times the height of Mount Everest!!
Worm Grunting:
1st phyla we will talk about and what we will cover in the lab today is…
A saw or leaf spring of a pick-up
stob

32. Class Hirudinea
1st phyla we will talk about and what we will cover in the lab today is…

33. Class Hirudinea
usually freshwater but there are some marine and terrestrial species
no septa between metameres
no setae
have 2 suckers

34. Class Hirudinea
have an extendable proboscis for feeding

35. Class Hirudinea usually have a fixed number of segments (34)
each metamere consists of several annuli (think accordion)
1 metamere
annuli

36. Class Hirudinea Locomotion
Lack septa between metameres, so they are incapable of moving like Oligochaetes.
Instead, they use their anterior and posterior suckers to move.
1st phyla we will talk about and what we will cover in the lab today is…

37. Class Hirudinea Reproduction usually monoecious cross-fertilize by
exchanging sperm
1st phyla we will talk about and what we will cover in the lab today is…

38. 38

39. Ecology
Although some leeches are parasitic blood suckers (can be temporary or permanent), many are predators.
1st phyla we will talk about and what we will cover in the lab today is…

40. Ecology
video
Leeches have been used medicinally since the 19th century.
Currently they are used to increase blood flow following reconstructive surgery
Hirudin is a powerful anticoagulant that is found in the salivary glands of leeches
Leech saliva contains antiseptic chemicals
And an anesthetic
1st phyla we will talk about and what we will cover in the lab today is…
DON’T WRITE THIS DOWN, YOU HAVE AN ARTICLE AND VIDEO WITH THE INFO

41. Class Polychaeta
1st phyla we will talk about and what we will cover in the lab today is…

42. Class Polychaeta all marine
this class contains 2/3 of all known Annelids
have a well developed head with specialized sense organs
1st phyla we will talk about and what we will cover in the lab today is…

43. Class Polychaeta
have many setae (chitonous bristles secreted by the epidermis)
(Poly = many, chaeta= setae)
these setae are arranged in bundles on paddle-like appendages called parapodia
1st phyla we will talk about and what we will cover in the lab today is…
setae

44. Class Polychaeta
Parapodium
1st phyla we will talk about and what we will cover in the lab today is…
setae
The parapodia function in gas exchange, locomotion, and feeding.

45. Class Polychaeta Tagmatization (tagmosis)
the fusion and specialization of formerly metameric segments
1st phyla we will talk about and what we will cover in the lab today is…

46. Class Polychaeta Many are filter-feeders with specialized structures
1st phyla we will talk about and what we will cover in the lab today is…

47. Class Polychaeta Many are predatory with specialized structures
1st phyla we will talk about and what we will cover in the lab today is…

48. Class Polychaeta
1st phyla we will talk about and what we will cover in the lab today is…
Many construct their own homes out of CaCO3 or sand debris and mucous

49. Class Polychaeta Reproduction usually dioecious (separate sexes)
no permanent sex organs; gametes are shed into coelom
fertilization is usually external
indirect development  trocophore larvae
1st phyla we will talk about and what we will cover in the lab today is…

50. Ecology Polychaetes often have effective defense strategies:
some have tubes to hide in
some have vicious jaws
some have modified “stinging” setae
1st phyla we will talk about and what we will cover in the lab today is…
a fireworm

51. Ecology A type of symbiosis
Some Polychaetes have a mutualistic relationship with their host
for example, many scaleworms are found near, or in the mouth, of brittlestars, starfish, and sea urchins.
The scaleworm eats its host’s leftovers and with its vicious jaws, it will attack any predator trying to eat it’s host.
1st phyla we will talk about and what we will cover in the lab today is…

52. How do the Annelids fit in?
Oligochaeta
Hirudinea
Polychaeta
Nematoda
Rotifera
metamerism
Nemertea
Platyhelminthes
Cnidaria
Porifera
eucoelomate
protostome
unknown
common ancestor

54. Segmented Worm Quiz on Topics Labs Video Med. Uses of Leeches (binder)
Phylum Annelida and 3 classes
General Characteristics and Examples of each
Vocabulary: monecious, dioecious, mutualism, tagmosis, detritus, triploblastic, coelom, septa, cerebral ganglia, parapodia, setae, parts of the worm anatomy from the lab
Labs
Earthworm behavior (binder)
Earthworm Dissection (binder)
Video Med. Uses of Leeches (binder)
Quiz- short topic
Text Reading
Worksheet