11 Phylum Annelida

Question 1

Mostly a free living group of an estimated 15,000 species, found all around the world, in our soil, in rivers and even in the deepest part of the ocean.

Answer 1

Phylum Annelida

Question 2

(annelus) means

Answer 2

’’ little rings”

Question 3

Level of complexity of phylum annelida.

Answer 3

Organ-system grade

Question 4

• Segmented worms: displays a metameric body plan
• 15,000 species
• Worldwide distribution. 1 class is chiefly marine, the rest are freshwater
  and terrestrial.
• Most free-living, some symbiotic, some ectoparasitic
• Bilaterally symmetrical, often with distinct head
• Triploblastic

Answer 4

Phylum Annelida

Question 5

External Body Plan:

Answer 5

2 head portion
segmented body portion
epidermis

Question 6

Head Portion (2 parts)

Answer 6

prostomium
peristomium

Question 7

Part of 1st segment. It is in front of (but does not include) the mouth, usually a small lip-like extension over the mouth. Sometimes bear sensory palps or tentacles.

Answer 7

Prostomium

Question 8

1st TRUE body segment. Directly behind prostomium and contains the mouth.
Predatory/parasitic forms may contain jaws or teeth

Answer 8

peristomium

Question 9

Body is divided into similar segments

Answer 9

metameres

Question 10

externally marked by circular rings in between each metamere.

Answer 10

annuli

Question 11

The terminal/last portion; also bears the anus

Answer 11

Pygidium

Question 12

Epithelium secretes thin outer layer of cuticle made of collagen.

Answer 12

Epidermis

Question 12

Tiny bristles made of chitin found in epidermis.

Answer 12

Setae

Question 13

Short and needle-like in earthworms

Answer 13

(Class Oligochaeta)

Question 14

Long and hair-like in polychaetes

Answer 14

( class polychaetes)

Question 15

Absent in leeches

Answer 15

(Class Hirudinida)

Question 16

(allowing lengthening/shortening of body)

Answer 16

inner longitudinal

Question 16

(allowing increase/decrease in
diameter)

Answer 16

outer circular

Question 16

– has a true body cavity

Answer 16

Eucoelomate

Question 17

hence, eu- means

Answer 17

“true”

Question 18

-coelom means

Answer 18

“cavity”

Question 18

holds organs in place

Answer 18

peritoneum

Question 19

acts like an expanding storage compartment. Absent in some earthworms.

Answer 19

crop

Question 20

– strong, muscular organ. For grounding food and minerals.

Answer 20

gizzard

Question 21

the “hearts”, usually 5 pairs. Pumps blood to the 2 main blood vessels

Answer 21

Aortic Arches

Question 21

(blood is contained and circulates the body within vessels)

Answer 21

closed type Circulatory system

Question 22

which branched off from the major vessels, are found in each segment

Answer 22

transverse vessels

Question 22

2 major blood vessels

Answer 22

Dorsal blood vessel and Ventral blood vessel

Question 23

present around the pharynx, and connected to ventral nerve cord

Answer 23

cerebral ganglia

Question 23

primitive “kidney” but better than protonephridia (meta- means “higher”)

Answer 23

Metanephridia

Question 24

terminal opening where waste and water is excreted out the body; Found near the ventral row of setae in each segment

Answer 24

Nephridiopore

Question 25

Some from Class Polychaeta can asexually reproduce by

Answer 25

fission and fragmentation/budding

Question 26

Earthworm (Class Oligochaeta) and Leeches (Class Hirudinida) are:

Answer 26

monoecious

Question 26

a thickened glandular, nonsegmented section of body wall near the head in earthworms and leeches that functions in the storage of eggs

Answer 26

clitellum

Question 27

Class Polycheata are:

Answer 27

dioecious

Question 28

(poly =_______ + chaite=________)

Answer 28

many, long hair

Question 28

Largest class of annelids (>10,000 species) * Mostly marine, some freshwater * Has a distinct head * Mostly live under rocks, coral crevices, or in abandoned shells; Some burrow into mud or sand and build their own tubes * Important in marine food chain (eaten by fish, crustaceans, hydroids, etc.) * Some members are sedentary/sessile, some are errant (free-moving)

Answer 28

CLASS POLYCHAETA

Question 29

may have eyes, tentacles, and sensory palps.

Answer 29

Prostomium

Question 30

Peristomium may bear setae around mouth or have chitinous teeth or jaws

Answer 30

Peristomium

Question 31

sexually immature

Answer 31

"atokes"

Question 31

sexually mature

Answer 31

“Epitokes”

Question 32

Only class of Annelida with a larval form, called a

Answer 32

trocophore

Question 33

(oligus = _____ + chaite = ______)

Answer 33

"few, long hair

Question 34

Setae is less numerous than polychaetes and only found on the ventral surface of the first several segments * Head indistinct/absent (but still display cephalization) * Number of segments are variable * Scavengers, feeding on decaying organic matter and vegetation

Answer 34

CLASS OLIGOCHAETA

Question 35

Male genital ducts are found in

Answer 35

segment 15

Question 36

Female genital pores are found in

Answer 36

segment 14

Question 37

Sperm from mate is received and stored in 2 pairs of seminal vesicles in

Answer 37

segment 9 and 10

Question 38

When mating, worms bring their anterio-ventral surfaces together and held together by mucus secreted by the

Answer 38

clitellum

Question 39

mucus will form a

Answer 39

cocoon

Question 40

Setae are absent * Aquatic; predominantly freshwater, few marine, some moist terrestrials * More abundant in tropical regions * Almost flattened dorsoventally * Known ectoparasites of carnivores and small invertebrates

Answer 40

CLASS HIRUDINIDA

Question 40

are considered the “true” leeches

Answer 40

CLASS HIRUDINIDA

Question 41

(for cutting through skin in order to feed on blood)

Answer 41

Chitinous jaws/cutting plates

Question 41

used for locomotion (instead of setae)

Answer 41

anterior and posterior suckers

Question 42

sperm is transferred by a spermatophore that penetrates the skin of their mate (called

Answer 42

hypodermic impregnation

Question 42

This is the largest class of Annelida that is exclusively marine.

Answer 42

Polychaeta

Question 43

This refers to the body segment containing the mouth.

Answer 43

Peristomium

Question 44

The members of this class do not have setae.

Answer 44

Hirudinida

Question 45

How do leeches move around?

Answer 45

using suckers