Lec 10 - cestodes Flashcards
Structural characteristics of tapeworms
Have lost mouth, gut, anus, etc as an adaptation to their lifestyle
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Do cestodes have a tegument
Yes
Do cestodes have a gut
No
1 thing (4 now)
COMPARE the tegument of cestodes and flukes similar
Cestodes use the tegument to increase surface area, as it has mitotriches/projections
whereas, in flukes, the tegument presents antigens to hide from our immune system
six thingS
Cestode general life history
****In definitve host **
Adult
Egg
Larval forms in intermediate host
Oncosphere
Metacestode
Adult
What mode of transmission to cestodes generally use
They use fecal oral from definitve host (to get the eggs laid)
Then Trophic - so the intermediate host will be eaten by the definitive host
2 things
What are the two general controls that apply to most parasites (if not all!)
- Public education
- Inc personal wealth
What are the 3 examples of parasites impacting the enivroment in a different way then just being a parasite
- Moose in Mount Tremblant
- Mudflat in New Zealand - Ecosystem engineer example
- Biomass study done (the one with the graphs)
Describe the mud flat ecosystem engineer example & how it affects the local enviroment
Normally cockles burrow into the sediment with only their siphons protruding but when the cockles are infected by trematodes, they have impaired digging abilites, not allowing them to dig into the sediment. This serves as a new habitat/home for other orgs to live.
This INC biodiversity in the local envioment
What are the 3 raw fish worms
Clonorchis
Diphyllobothrium
Anisakiasis
How many intermediate stages are there in Diphyllobothriidea
2 Intermediate stages
Why is Diphyllobothriidea known as the Broad fish tapeworm
Because each proglottid is wider than it is long
Write out jot notes to help you
What is the life cycle of Diphyllobothriidea (2/3 raw fish worm)
- Definitve host is fish-eating mammal - eggs get passed w/ feces
- Hatches in fresh water in a free swimming, cilliated form known as coracidium
- Gets eaten by Copepod (1st intermediate host.
- Procercoid develops in the hemocoel
- Fish eats Copepod
- The plerocercoid develops in the fish muscle
- Fish eating mammal eats the fish
Diphyllobothriidea has a paratenic aspect to it. explain.
In Diphyllobothriidea large fish eating fish (piscivorous fish) can be intermediate & paratenic hosts. This is because a larger fish will eat the smaller infected fish that has the plerocercoid(infected stage) inside of it. Then a fish eating mammal will eat that large fish. So in a sense, that large fish was a paratenic host as it was temporarily holding the parasite w/out any development, until it is eaten by the definitive host!
Control of Diphyllobothrium
Flash freeze the fish right when it has been caught to kill off the parasite before sending it off to market
3 things
Symptoms of Diphyllobothrium
- Mostly asymptomatic/mild - abdominal pain, diarrhea, vomiting
- Severe B12 defiency, leading to anemia over time
- Chronic infections: Degeneration of the spinal cord and neurological symptoms
What drug is Diphyllobothrium treated with
Praziquantel
What is sparganosis
Accidental infection with plerocercoids
3 things
How can you get sparganosis
- poulticing with frog flesh (traditional east asian medication)
- accidently drinking water with infected copepods
- eating raw/undercooked amphibians , birds, reptiles
3 things
What are the symptoms of sparganosis
They vary. It will vary based on where the nodule resides in the tissue. The nodule can also migrate
Commonly, there will be pain/ inflammation in the surrounding tissue
Ocular nodules can lead to
blindness
Nodules in the brain can lead to
death
What is the best treatment to get rid of a sparganosis nodule
Surgical treatment to have it removed
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What is the name of model system for the aquatic tapeworm
Three spined Stickleback tapeworm
Scientific name: Schistocephalus solidus
2 things
What does the three spinedstickle back tapeworm (schistocephalus solidus) do to fish?
- Causes behavioural modification
- infected fish less likely to swim in it’s pool
- it continues to feed when startled
- flashes its belly while swimming, becoming much more visible to its predator. The bird, the definitive host
2.Habitat preferance change
- the fish start to prefer warmer water preffering around ~20 degrees celcius whereas normally they like to be in 15 degrees celcius water
- as stickleback makes more eggs in the heat
Why is climate change alarming in the case of stickleback (schistocephalus solidus)
it may spawn an outburst of the disease.
as stickleback eggs (schistocephalus solidus) as they make more eggs in warmer temperature
When doing research on ecosystem energies , what was found about parasites?
It was found that it in some cases, parasites had a larger biomass then some of the top predators!
