Platyhelmenthes Flashcards
Phylum- Platyhelminthes
Classes- (3)
Turbellaria (planarians)
Trematoda (flukes)
Cestoda (tapeworm)
Class Turbellaria
genus-
dugesia (planarians)
Class Trematoda
Genus-
fasicola (flukes)
Class Cestoda
genus-
taenia (tapeworm)
What kind of germ layers?
triploblastic
ectoderm, mesoderm, endoderm
do they have a coelom?
No, acelomate no body cavity just parenchyma
symmetry? cephalization?
bilateral
yes, obvious head end
Turbellaria -dugesia (planarians)
Feeding strategies
Evert ventral pharynx to feed,
GV cavity branches into diverticula
free living predators and scavengers
Turbellaria -dugesia (planarians)
Characteristics:
cilliated ventral side to move, only one opening,
simple life cycle, can regenerate
Trematoda- fasicola (flukes) and
Cestoda- taenia (tapeworm)
endoparasite, tough syncytial tegument, no cilia
Cestoda- taenia (tapeworm)
Characteristics:
no mouth or gut, have a scolex for hooking, made of proglottids
Trematoda- fasicola (flukes)
Characteristics:
Life cycle needs intermediate host (snail in larval stages, asexual) and definitive host (sheep liver in adult, sexual). Can be mono or dioecious
Trematoda- fasicola (flukes) life cycle
Egg> miracidium >sporocyst> rediae>(out of snaill) cercariae> metacercarial cyst >(into sheep) metacercaria
Cestoda- taenia (tapeworm) life cycle
definitive host Ingestion of worm> attaches to intestines and matures > detach proglottids into feces >pig eats the larva> (intermediate host) larva encysts in pig muscle> definitive host eats pig meat
Turbellaria -dugesia (planarians) cilia and Rhabdite cells
cillia work with Rhabdite cells to produce mucus so they have a “slime” trail
Turbellaria -dugesia (planarians) organ system
osmoregulatory - regualte body fluids like a network of tubes in parenchyma. the tubes end at the flame cell.
protoniphridia= flame cell
tuft of cilia/flagella surrounded by a sieve-like structure made of microfibrils selective of certain ions.
tuft inside the cell “beats” to excrete waste
tapeworm larva
oncosphere
Intermediate host: final host
Sexual reproduction of endoparasites occurs in only one animal host, the final or definitive host, while asexual reproduction of the parasite can occur in the intermediate host(s) and sometimes also in the final host.
