class trematoda Flashcards
what class is the fluke included
class trematoda
Flukes under this class are dorso-vetrally flattened, unsegmented and have leaf-like body.
class trematoda
subclasses of trematoda
monogenea
digenea
aspidogastrea
this subclass has a direct life cycle/ no IH which needs only 1 host
monogenea
animals that are monogenea
most endoparasite of fishes, amphibians and reptiles
this subclass under trematoda is of great importance in veterinary medicine
digenea
subclass that has indirect life cycle and needs 2 host for reproduction
digenea
parasites included in digenea
endoparasites in domestic and wild animals
in digenea, what reproduction happens in IH and in FH
sexual in FH and asexual in IH
Parasitic in or on fishes, turtles, molluscs or crustacea
aspidogastrea
Digenetic Trematodes)
digenea
These trematodes are hermaphroditic endoparasites except for the
Schistosomes in which they have a separate male and female sex organs
digenea
Sex organs
of male digentic trematodes are composed of
Testes, Vas efferens, Vas
deferrens, Seminal vesicle, Prostate gland and Cirrus.
this organ may be present which encloses the Seminal vesicle, prostate glands and the
cirrus.
cirrus or cirrus sac
digenetic trematode female sex organ is composed of:
Ovary, oviduct (with
receptaculum semenis, Laurel’s canal), ootype and uterus.
a narrow canal opening on the dorsal surface of the body. It serves as an outlet of
injurious materials used for making shells of the eggs
laurel’s canal
consisting of follicles that discharges yolk materials into the yolk duct which joins the oviduct in a wide portion
vitellaria or paired vitelline or yolk glands
the unicellular glands that surrounds the ootype where eggs are formed
mehli’s gland or shell gland
Shells are formed by
secretions of vitelline and Mehli’s glands
life cycle of digenetic trematodes in general
egg-miracidium-sporocyst-redia-cercaria-metacercaria-immature fluke in liver parenchyma-adult fluke in bile ducts
what do you call the larva that hatches from the egg
miracidium
roughly triangular in shape with ciliated covering and free-swimming in water. They may have anterior spine for boring into the intermediate host which are usually snails.
miracidium
After the miracidium penetrates the snail host (IH), the ciliated covering is lost
and eventually becomes a
sporocyst
These sporocyst then gives rise to another larval stage known as the
redia
The redia has
oral sucker, pharynx, and sac like intestines
Furthermore, the redial stage will produce the final stage which is known as
cercaria
produce from the germinal cells of the sporocyct or redia in other species
cercaria
has suckers, intestines, excretory and nervous systems, special glands and sometimes anterior spine.
cercaria
what grows in cercaria which is used for swimming or propelling itself out of the snail
a tail
These cercaria may encyst in herbage and
vegetation or second Intermediate hosts. The encysted cercaria is known as the
metacercaria
phenomenon of producing many individuals
by single egg/ larva.
paedogenesis/polyembryo
Modes of transmission of cercaria to the animal host
- Dringking water contaminated with cercariae/ metacercariae
- Ingestion of metacercariae in herbage
- Ingestion of Intermediate host (snails)
- Penetration of intact skin by Schistosome cercariae
Classification of flukes according to anatomical structures (the nature and
location of suckers, shape or body, etc.)
monostome
distome
amphistome
holostome
echinostome
schistosome
only the oral sucker is present, they do not have ventral sucker.
monostome
both oral and ventral suckers are present, ventral sucker is away
from posterior end.
distome
the oral and ventral suckers present at each extremity.
amphistome
the body has characteristic constriction, dividing the body into two portions.
holostome
characterized by the presence of head collar with spines
echinostome
characterized by the separate sex or unisexual (male and
female) unlike the other species.
schistosome
Classification of Cercariae based on tail development
cercariaeum
microcercous
leptocercous
lophocercous
furcocercous
xiphidiocercariae
cercariae that has no tail
cercariaeum
cercariae that has a small, stumpy tail
microcercous
cercaria with long, simple tail
leptocercous
cercariae that the body has dorsal, long undulating fin fold tail
lophocercous
cercariae where tha tail bifurcates distally
furcocercous
cercariae that has an oral sucker equipped with anterior spone
xiphidiocercariae
