Trematodes

Question 1

Give an example of Trematodes

Answer 1

Flukes and flatworm

Question 2

Small dorso-ventrally
flattened worms with
simple anatomy and
without segmentation

Answer 2

Tematodes

Question 3

Do they have coelom?

Answer 3

NOPE

Question 4

Describe trematodes

Answer 4

Digenea posses two
suckers (oral and ventral
acetabulum) which they use
to attach within the host.
Oral sucker contains the
mouth
• Muscular pharynx permits
the worm to pump food into
the blind-ending gut
• Most trematodes are
hermaphrodites (they are
male and female, and
cross- as well as selffertilization
occurs)

Question 5

Describe the gut of trematodes

Answer 5

The gut of trematodes is
blind-ending but can be
quite extensive and highly
branched

Question 6

The gut is not the only organ
these worms use for food
uptake. What else?

Answer 6

The tegument

Question 7

A protonephridium consists of what?

Answer 7

flame cell and tubule cell

Question 8

Trematodes are massively fertile but their lovelife is complex. T or F

Answer 8

True

Question 9

Are the adults hermaphrodite?

Answer 9

Yes

Question 10

Describe the reproductive system of trematodes

Answer 10

The reproductive system
takes up a large portion of
the body of the animal

Question 11

What do you call the urinary system of trematodes?

Answer 11

Protonephridia

Question 12

Trematodes form _________ eggs

Answer 12

ectolecithal

- oocytes meet with the yolk cells in the ootype which is surrounded by Mehlis gland.

Question 13

Reproduction cycle: steps

Answer 13

Trematodes form complex ectolecithal eggs
Worm eggs travel through the uterus to the genital pore.
Egg shell is hardened by quinone tanning
Tyrosine is modified into a highly reactive quinone.
Cross liks free aminio groups

Question 14

Reproduction cycles

Answer 14

Asexual and sexual

Question 15

What does the egg contain?

Answer 15

The embryo instead of an oocyte

Question 16

T or F: The eggs have to leave the body of the final host to continue development.

Answer 16

T

Question 17

is highly motile

due to the cilia on its surface

Answer 17

Miracidium

Question 18

have simple eyes
(they avoid light) and several
chemical and mechanical
receptors which they use to
find the intermediate snail host

Answer 18

Miracidium

Question 19

After penetration the
miracidium undergoes
metamorphosis into the __________

Answer 19

sporocyst

Question 20

This stage has most organ
systems reduced to the bare
minimum and acts as a
germinal sac

Answer 20

Sporocyst

Question 21

takes up
nutrients only over its
tegument and the germinal
mass expands and develops
into daughter sporocysts,
redia or cercaria

Answer 21

sporocyst

Question 22

are the stages
that leave the intermediate
host and infect the final
host

Answer 22

Cercaria

Question 23

Sporocyst can produce
cercaria or a next
amplification
generation, _______

Answer 23

redia

Question 24

have features of
the adult fluke like oral
and ventral sucker, a
gut and “birth pore” to
release cercaria

Answer 24

redia

Question 25

are mobile in the
snail and can prey on
sporocysts and redia of
the same or other
species (competition)

Answer 25

redia

Question 26

The lancet fluke

Answer 26

Dicrocoelium dendriticum

Question 27

manipulates the behavior
of the ant. In the evening
when the temperature
drops they experience
spasms of their
mandibles

Answer 27

The brain worm

Question 28

is a
tiny digenic trematode
living in the gut of small
song birds

Answer 28

Leucochloridium sp.

Question 29

Human fluke is caused by

Answer 29

Clonorchis sinensis and opistorchis felinus

Question 30

Transmission

Answer 30

Metacercaria are found in
many fish especially various
carp related species
• Raw or undercooked fish
dishes are a source of
human infection
• Fertilization of ponds with
untreated night soil boost
infection in fish
• Cats, dogs and other
carnivores can be additional
hosts and reservoirs

Question 31

Describe heavy infection of LIVER flukes

Answer 31

residing in the biliary
ducts can chronically
irritate the epithelium
resulting in hyperplasia of
the epithelium and
fibrosis around the ducts
(pipe stem fibrosis)

Question 32

Diagnosis

Answer 32

Diagnosis occurs by
microscopic
demonstrations of fluke
eggs in the feces

Question 33

is best known but a number
of other species infect
humans around the world. Can get from eating crabs

Answer 33

Paragonimus westermanii

Question 34

Chronic high worm burden can

result in

Answer 34

chronic bronchitis and
dyspnea and increasing
fibrosis -- symptoms can be
very similar to pulmonary
tuberculosis

Question 35

Important parasite of
livestock, occasionally
infects humans

Answer 35

Fasciola & Fasciolopsis