Lecture 1 - cetacean parasitic disease Flashcards
what different relationships are there amongst organisms? (describe)
without damage
- mutualsim (+/+)
- commensalism (+/0)
with damage
- predatorism
- parasitism (+/-)
different forms of parasitism
obligate parasitism
- permanent
- temporary
- periodic
Obligate parasites are completely dependent on the host in order to complete their life cycle; they remain in contact with the host at least during one period of their life cycle
facultative parasite
accidental parasite
endoparsitism
= parasites that live inside the hosts body
- Picture left –> Lungworms (Nematodes)
- Picture right –> tape worm (present in dolphins)
ectoparasitism
= parasites that live on the skin surface or in the thickness of the skin of the host (copepods, leeches, whale lice)
polyparasitism
pseudiparasitism
e.g. looking at carnivore-feces:
- parasites of host
- and parasites of prey
it is then Important to recognize and distinguish them
What can you use parasites for, that you obtain from feces ?
useful for
- Genetic analysis
- to see what parasites live in wild population
parasites with different life-cycles
–> what life-cycles?
- direct LC = monotonous parasite
- indirect LC = eteroxenous parasite
Monoxenous parasite
- parasite with direct evolution on a single host with or without a free phase in the external environment
- direct life cycle
Eteroxenous parasite
- with one or more intermediate hosts
- indirect life cycle
what types of hosts are there?
- intermediate host
- definitive host
- paratenic host
- accidental host
intermediate host
- necessary for LC-completion
- hosts 1/>1 larval stages
definitive host
- necessary for LC-completio
- hosts adult stage
- parasites reaches sex. maturity in this host
paratenic host
- not necessary for LC completion
- but can be important because it’s a host in which the larva stage can usually be accumulated
- parasite usually doesn’t harm the paratenic host
- It is a strategy!!
- Typical example is Anisakis as accumulator for larval stages
accidental host
- not necessary for LC completion
- parasite can survive in here
- not an important host
this is usually in a balance
determinants of (parasitic) disease
3 main components
- Etiologic agent (etiologic = causing or contributing to the development of a disease or condition)
- Host
- Environment
Conservation status of carcasses in cetaceans
- Code for analyzing parasites
- You can obtain information about parasites from the codes 1 - 3
why should a parasitological examination be done?
(according to the conservation code of the carcass)
parasitological examination can be done where?
- skin
- kidney
- blubber
- body cavity
- lungs
- GIT
Why is a parasitological examination important in food chain?
- Especially for parasites with indirect LC
- imagine when a parasite needs more than 1 host and you detect it in an environment of one of the intermediate hosts
–> when parasite in ALL intermediate hosts then environment is in balance
–> it is working and healthy
means there is an exchange of parasites in all (stages?)
what are epibionts?
ectoparasites or commensals
epibionts on the skin
what parasite is that?
Xenobalanus globicipitis (Crustacea Cirripedia)
What parasite is that?
what parasite is that?
- Common in whale eyes
- High host-specificity
- Remain entire life on host obligate
- Need direct contact for transmission
what are lice ( = Läuse) used for?
- they are great candidates for biological tags to study whale migration routes
how can whale migration routes be studies?
what is that?
Pennella spp
(Crustacea, Pennelidae)
what is that?
Pennella spp
(Crustacea, Pennelidae)
Life cycle of Pennella spp.
immature stages of Pennella balaenoptera vs pennella filosa
- Pennella balaenoptera in fin whales only
- they are molecularly the same species
Answers:
1. In the blubber.
2. C. delphini.
3. A cyst with a neck.
4. The white part of the blubber indicates the presence of the cyst.
- In the liver and the last part of the intestine.
- C. grimaldii larvae are smaller, lack cysts, and have plerocercoid larvae with four suckers.
- It hosts the larval stage, which does not fully develop into the adult form until it reaches the definitive host.
- Cephalopods.
- The larval stage develops in the intermediate host, requiring a different organ environment and morphology to adapt.
- A white cyst in the blubber.
Near the perigenital tract in the belly blubber. - This area is commonly bitten by sharks, the definitive host.
- Sharks bite the intermediate host, consuming the parasite.
- They are found in the liver.
- The larvae are smaller and difficult to observe.
- Much is unknown; however, for some species, the adult worms live inside the intestines of large sharks.
- They are hermaphrodites.
- Three different species.
- Morphological differences can be misleading, as they often appear distinct but are molecularly similar.
- Cetaceans act as the intermediate host.
- It highlights significant gaps in knowledge, emphasizing the need for further studies.
- It is found in the subcutaneous fascia, between the blubber and muscle.
- Greater than 1 meter.
- Its length makes it challenging to extract fully.
- They produce larvae eggs.
- It is unclear how their eggs are released from the host.
- The lifecycle remains largely unknown.
- Males provide critical information for species identification.
- Muscle and subcutaneous fascia.
- In the air sinuses and Mediterranean waters.
- C. boopis and C. grampicola.
- In the kidney, specifically with females found in the cava vein.
- It destroys muscles while feeding on blood.
- The tails of the parasite are visible in the posterior part of the kidney.
- Through the urine.
The host initiates an inflammatory reaction to kill the parasite.
- Severe infections can lead to organ failure and even death.
- Calves and juveniles.
- Organ failure due to heavy infections.
- Through direct lifecycle transmission during lactation.
- Via the urine of the infected host.
- The anterior part affects the kidney parenchyma, while the tails remain as before.
- It is unclear if the lifecycle is direct or not.
Deepwater squid.
What issue is caused by parasites in cetaceans regarding echolocation?
They can disrupt or impair echolocation.
- These parasites usually do not cause severe lesions.
- Dolphins.
- The presence of certain parasites.
- They can block or stop food progression in the digestive system.
- Their names are often linked to their specific morphology.
- To the mucosa in specific channels.
- What size can intestinal tapeworms in marine hosts reach?
- What structures of the tapeworm are filled with eggs?
- How can humans become infected by tapeworms from marine hosts?
- What is the lifecycle progression of these tapeworms in humans?
- They can grow to 10 meters or longer.
- The proglottids.
- By consuming raw fish, becoming a definitive host.
- Humans release eggs in freshwater, which are taken up by small crustaceans, and eventually infect intermediate or definitive hosts.
- Up to 30 meters, often divided into three 10-meter sections.
- Certain parasites may only be observable in specific sections of the intestines.
Where do Campula species reside in marine hosts?
Inside the liver ducts.
- The Pseudaliidae family.
- Seven different genera.
- Juveniles and calves.
- Pneumonia.
- Morphologically identical species can differ genetically.
- Two morphologically distinct species were found to be genetically identical but adapted to different hosts.
Larvae
