Zoology Lab 3

Question 1

Phylum Rotifera : Key traits

Answer 1

• They have a true alimentary canal with a mouth and anus.
• Have a set of jaws called the mastax.
• The body can be differentiated in 3 regions : head, trunk and foot.
• Have a large corona on the anterior end.

Question 2

Phylum Nematoda : Key traits

Answer 2

• Within the clade Ecdysozoa
• Undergo a process of ecdysis of their cuticle
• called Roundworms.
• Most free living and some important parasites of plants.

Question 3

Nematode sexual reproduction

Answer 3

• Have separate sexes ( dioecious)
• Female are larger than males
• The posterior end of the male is sharply curve.

Question 4

Identify the missing parts

Answer 4

Question 5

Clade?
Phylum ?
Try to identify the structures. (corona, pharynx, mastax, stomach)

Answer 5

Lophotrochozoa
Phylum Rotifera

Question 6

Phylum ?
Clade?
Name of slide?
Is there a layer of muscle tissue adjacent to the gut?
Male or female?

Answer 6

Phylum : Nematoda
Clade : Ecdysozoa
Ascaris cross section
Yes, muscle just underneath epidermis.
Male

Question 7

Male or female ?
Clade ?
Phylum ?

Answer 7

Female
Ecdysozoa
phylum = nematoda

Question 8

How do nematodes move?

Answer 8

• Nematodes use the fluid in their pseudocoelom as a hydrostatic skeleton that allow movement.
• As one set of muscles contracts, the opposing group must expand to accomodate the fluid.

Question 9

Name
Phylum ?
Clade?

Answer 9

Vinegar eel ( Anguillula aceti)
Phylum: Nematoda
Clade : Ecdysozoa

Question 10

Phylum ?
Clade?
Lifestyle ? (herbivore or bacterivore)

Answer 10

Ancylostoma duodenale
Phylum : Nematoda
Clade: Ecdysozoa
Bacterivore

Question 11

Phylum ?
clade ?
Lifestyle ?

Answer 11

Vinegar eel
Phylum: Nematoda
Clade : Ecdysozoa
Herbivore

Question 12

Name ?
Phylum?
Clade?
Class?

Answer 12

Earthworm
Phylum = Annelida
Clade = Lophotrochozoa
Class : Oligochaeata

Question 13

Observe the mouth, pharynx , crop and gizzard.

Answer 13

Question 14

Name of slide ?
Clade
Phylum ?
Class?

Answer 14

Cross-section of an earthworm
Clade : Lophotrochozoa
class : Oligochaeta
Phylum : Annelida

Question 15

How many tissues layer?
Det. which type of body cavity
Any support structures ?

Answer 15

They are triploblastic
Body cavity = coelomate
support structures = coelomic fluid acts as hydrostatic skeleton

Question 16

Phylum?
Clade?
Class?

Answer 16

Phylum : Annelida
Clade: Lophotrochozoa
Class : Hirudinea

Question 17

Leeches have what kind of reproduction ?

Answer 17

They are monoecious

Question 18

Clade?
Phylum ?
Class?
Are members aquatic, terrestrial or both ?

Answer 18

Clade = Lophotrochozoa
Phylum = Annelida
Class= Polychaeta
They are aquatic and almost all species are marine dwelling.

Question 19

Class ? 
What does the class signifies ?

Answer 19

Polychaeta
It means that they have many chaetae.

Question 20

Male anatomy
Ascaris morphology

Answer 20

Question 21

Female cross-section

Ascaris

Answer 21

Question 22

What does parapodia means ?
Where do you find this strucuture in ?

Answer 22

• They are chaetae that have a paddle like structure which occurs at the side of the body.
• You find this structure in the clade lophotrochozoa, phylum annelida and class polychaeta

Question 23

What is the function of the thin cuticle layer on the outside of the earthworm?

Answer 23

It helps retain the water.

Question 24

What is the name of the bristles on the underside of the earthworm?

what does oligo stand for ?

Answer 24

Chaeta or setae

oligo = few

Question 25

The muscular arrangement of annelids

Answer 25

• Body wall contain longitudinal & circular muscle for burrowing and swimming.
• Movement is by their circular muscles which expand and contract, moving the animal forward as well as side to side.

Question 26

What kind of muscle does nematodes have ?

Answer 26

• Just inside their gut are the longitudinal muscles; unlike other worms (annelids), the nematodes lack a circular muscle and so their movement is restricted to a side-to-side whip.

Question 27

What is the main difference between the phylum nematoda and annelida ?

Answer 27

• So basically the main difference in the two phylum is the presence or lack of circular muscle which is an important evolutionary step in annelids as it allows more effective movement

Question 28

What is the most distinguishing feature of the phylum annelida ?

Answer 28

• The most distinguishing feature of this group is segmentation, with the segments visible as rings around the body.

Question 29

What kind of predators are the leeches(class hirudinea) ?

Answer 29

Most are scavengers or predators of small invertebrates and some are blood feeding species.

Question 30

Where do leeches live ?

Answer 30

Most live in freshwater environements but there are also marine and terrestrial species.

Question 31

What is the most prominent feature of the class hirudinea ?

Answer 31

Is the presence of a large posterior sucker that aids in attachment for blood-feeding species but also serves other purposes.

Question 32

What are the similarities of leech to the other annelids ?

Answer 32

The leech does have segements though the segments are not seen.
And they do lack parapodia like the oligochaetes.

Question 33

Why is the anterior sucker smaller than the posterior sucker in leeches ?

Answer 33

Anterior suckers = use mainly as a feeding structure
Posterior sucker = for locomotion

Question 34

What are the feature that are specific to parasitic leeches ?

Answer 34

They have anticoagulant