tag:blogger.com,1999:blog-6094038346173044955.post5029974524425464477..comments2024-03-27T19:39:11.723-04:00Comments on Parasite of the Day: Anoplotaenia dasyuriSusan Perkinshttp://www.blogger.com/profile/05944116263349266952noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-6094038346173044955.post-19662202501909677002021-12-16T12:52:29.462-05:002021-12-16T12:52:29.462-05:00I found this parasite super interesting as this un...I found this parasite super interesting as this unique tapeworm infects the largest living carnivorous marsupial, Tasmanian Devil. It was very interesting to find out that these tapeworms thrive and flourish to their full potential only within Tassie devil’s gut, eventhough it can also thrive within other hosts such as spotted quoll and dogs. I was also surprised to know that despite having thousands of A. dasyuri in its guts, the Tassie devil can appear perfectly healthy with no signs of pathology. It was also quite shocking to know that the researchers were able to pull out 8100 tapeworms from just six infected Tassie devils!! And how they tested all individual 8100 tapeworms and sequenced their DNA to figure out their evolutionary origin. It was very interesting to read about Anoplotaenia dasyuri and how they evolved within the guts of Tasmanian Devil. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6094038346173044955.post-64693032389805824232021-12-16T03:41:58.309-05:002021-12-16T03:41:58.309-05:00It's quite likely that the reason the ancestor...It's quite likely that the reason the ancestor of this tapeworm ended up in a marsupial host is simply because marsupials happen to be occupying the ecological niche that is more likely to encounter this parasite (medium to large carnivores that feed mostly on terrestrial vertebrate prey).<br /><br />Its ancestor may have also jumped to other host too - but perhaps we just don't know about them yet. There is still a lot which are undiscovered about the parasite fauna of Australian animals.Tommy Leunghttps://www.blogger.com/profile/06421993204602775597noreply@blogger.comtag:blogger.com,1999:blog-6094038346173044955.post-15072957441664722922021-12-16T03:37:29.836-05:002021-12-16T03:37:29.836-05:00Well, a number of factors are in play here.
First...Well, a number of factors are in play here.<br /><br />First of all, the tapeworms aren't all that big - each of them only grow to a few centimetres in length, so their total biomass comparing with the host is pretty low. <br /><br />Secondly, the tapeworms are simply passively absorbing nutrient, as opposed to something like hookworms which suck on the host's blood, so they are not causing any direct damage to the host's tissue. As long as the host is in good condition and is able to find enough food, the amount that gets absorbed by those tapeworms might be negligible or at a level that does not compromise the host's health.<br /><br />Thirdly, there is some indication that there is a relationship between the lack of parasites and incidences of allergies and autoimmune disorders. There is a possibility that many of the parasites that have coevolved with their host for millions of years are in fact also keeping their immune systems in check. And the absences of those parasites may end up causing their host to develop various autoimmune-related diseases. <br />For example see: <br />Spencer, H. G., & Zuk, M. (2016). For host's sake: the pluses of parasite preservation. Trends in ecology & evolution, 31(5), 341-343.<br />https://www.sciencedirect.com/science/article/pii/S0169534716000665<br /><br />There are other species of malaria, but the one that are infecting humans are thriving - so it is unlikely that we'd have to consider giving them protected status any time soon. During the early 2010s, Dracunculus medinensis, or Guinea worm - which causes a very painful disease - was on the verge of being eradicated by the WHO, but they have since made a comeback because they have now switched to using dogs as their main mammal host instead of humans. But even then, at no point was protected status declared for them.<br /> <br />Ultimately, we humans determine what status to give to these organisms and there are many others organisms (no just parasites) which do not have any protection status which probably do deserve to have them. It's just that either humans don't know enough about them and do not care, or there are some bias against them simply due to the "yuck" factor.Tommy Leunghttps://www.blogger.com/profile/06421993204602775597noreply@blogger.comtag:blogger.com,1999:blog-6094038346173044955.post-58472226919648952012021-12-13T22:32:04.140-05:002021-12-13T22:32:04.140-05:00I found several interesting things about this helm...I found several interesting things about this helminth. I was intrigued by the fact that they were able to pick out almost 8000 tapeworms from the gut of just 6 Tasmanian devils. I also found it interesting that Anoplotaenia dasyuri conducts its life cycle through marsupial hosts even though they do find other non-marsupial hosts hospitable. I was wondering if there is a reason for the preference of a marsupial host or it’s just the highly likely probability of finding marsupials in Australia. Finally, the ability to jump between various hosts and able to adapt in different host environments is quite impressive. Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-6094038346173044955.post-14640817501727204562021-12-11T01:01:19.550-05:002021-12-11T01:01:19.550-05:00Tommy (not sure if it's better to address you ...Tommy (not sure if it's better to address you as Dr. Leung, or not) but I'm seriously interested to learn more by asking a couple of questions. You wrote that in one Tasmania devil carcass over 4,000 tapeworms of A. dasyuri were found yet being infested with these tapeworms is "rather innocuous" to the host. Surely that many (or half that number) would have some detrimental effect on the animal since the parasites would be taking nutrients from its host! Wouldn't it cause some sort of problems?<br /><br />My other question - is there be a sound reason for D. robusta to be declared a protected species other than rarity? After all, I can't imagine the Plasmodium species that cause malaria to be declared protected species if they were to become few in number. Or am I wrong?<br /><br />I sincerely hope you'll read this comment and respond as I somewhat baffled.<br /><br />Kind regards, Jude Isomhttps://www.blogger.com/profile/07964512001839569512noreply@blogger.com