Looks like a nice blog on parasites!

In spite of the summer break, here is a nice blog I came across today, "Parasite Ecology":

https://parasiteecology.wordpress.com/

Filled with cool parasite stories and funny cartoons for the young and the not so young scientists :)

Parasite of the month

Pleistophora mulleri

This microsporidian is a specialist parasite that replicates in the cells of the abdominal muscle of the freshwater amphipod Gammarus duebeni. Although it was initially found in the Irish sub-species G. d. celticus (Terry et al. 2003), an extended survey evidenced its presence in other sub-species of G. duebeni in Europe (Ironside et al. 2008). Infections by P. mulleri were found to reduce foraging abilities of G. d. celticus on smaller amphipod species and to increase predation risk by larger amphipods. Accordingly, the microsporidian can affect invasion process by reducing the predation of G. d. celticus on smaller invading species such as Crangonyx pseudogracilis, and to increase predation of infected individuals by larger invaders, such as G. pulex (Fielding et al. 2005).


It is only known to be transmitted between individuals through cannibalism (MacNeil et al. 2003). By comparing selectivity of cannibalism between infected and non-infected individuals, Bunke et al. (2015) showed the parasites to alter host behaviour. Indeed, healthy gammarids avoid preying on infected conspecifics while this is not the case for infected individuals. Although it is not clear if this alteration of host behaviour is adaptive or not for the parasite, the authors suggest it to be a by-product of infection, rather than a manipulation. Yet, the effects of cannibalism and of its alteration by P. mulleri on the invasion of C. pseudogracilis and G. pulex remain to be explored.

source for picture: http://cdn4.sci-news.com/images/2015/03/image_2618-Gammarus-duebeni-celticus.jpg

Parasite of the month

Nosema spp. 

These microsporidians parasitise invertebrates. Most nosema infect insects and the best-known parasitize bees. These get infected by ingesting spores of the fungus. Multiplication in the epithelial cells leads to the lysis of the infected cells and the release of new spores within 10 days. Transmission of nosema between individuals is facilitated by prophylaxis in eusocial bees. Nosema can prevent colonies to thrive in the spring, following overwintering, and are thus considered as a pest by beekeepers.

Nosemosis has become an emerging disease in the last decades and is now listed by the World Organization for Animal Health (Office International des Epizooties - OIE) because of its role in the worldwide decline of bees. A growing number of studies thus reveal the influence of pesticides in nosema outbreaks. For instance, Pettis et al. (2013) investigated the interaction between pesticide exposure and the susceptibility of the honeybee Apis millifera to the gut pathogen Nosema ceranae. The results indicate that bees exposed to pesticides were more likely to become infected.  Interestingly, fungicides had the strongest effect on bee's susceptibility to infection, confirming the high resistance of nosema spores to extreme environments. Moreover, the researchers found that in many samples, bees carried a significant proportion of pollens from weeds rather than from cultivated crops in the sampled areas. It is thus likely that the exposure of foraging bees to pesticides is currently underestimated.

source for picture: http://www.athbui.com/Nuachtlitir%20pics/California%20Beacha/Nosema%202012%20%2811%29.JPG

Parasite of the month

Anguillicola crassus (Anguillicoloides crassus)

 

This nematode infects the Japanese eel, Anguilla japonica. Free-living larvae settle in the substrate to get ingested by an intermadiate host, typically a copepod. Young eels get infected by feeding on infected copepods. Interestingly, when infected copepods are eaten by other fishes, the parasite remains alive and can be transmitted from these paratenic hosts to larger eels feeding on them. In the eel, the parasite migrates to the swim bladder where it sexually produces eggs and causes pathological damages (see Muñoz et al. 2015 and references therein). These eggs then pass through the digestive tract and are released into the water.

Importation of Japanese eels to many places of the world for aquaculture is believed to have facilitated the spillover of A. crassus to native eels (Dangel et al. 2013).  Within 30 years, most populations of European eels A. anguilla became infected and the parasite is now specializing to infect its novel host (Weclwaski et al. 2013). This rapid spread to native species is connected to the high plasticity of the parasite's life-cycle. Larval infections have been reported in a range of organisms, including aquatic insects and amphibians (Moravec &Skoríková 1998). Recent evidences suggest that the use of paratenic hosts might be facilitated by hyperparasitism of native parasites by A. crassus (Emde et al. 2013). As a consequence, very few measures can be installed to protect native species from this invader and the spillover continues to cause high mortality in native eel populations (Kirk 2003, Barry et al. 2014).

source for picture:http://web.abo.fi/instut/fisk/Fin/Parasiter/anguillicola.htm

Joensuu here we come!

Ecologists and evolutionary biologists will meet in Joensuu (Finland) on 9-11 February 2015. The meeting is organised under Oikos Finland and supported by Nordic Society Oikos, Suomen Biologian Seura Vanamo and by Societas Pro Fauna et Flora Fennica.

During two days, the Finnish national meeting for ecologists and evolutionary biologists will gather over 215 participants to the Joensuu Campus of the University of Eastern Finland.

Plenaries include Paula Harrison (Univ. Oxford), Anssi Karvonen (Univ. Jyväskylä), Elizabeth Borer (Univ. Minnesota) and Toni Laaksonen (Univ. Turku).

Here is a more detailed program: https://www.jyu.fi/bioenv/en/divisions/eko/ecology_meeting/Programme

source for picture: https://www.jyu.fi

28:06:42:12

The end is near!

Feels weird to finally see my name here (but good weird!): http://www.helsinki.fi/bio/tutkimus/vaitoskirjat/  

Here is a link to the electronic version of my doctoral dissertation: https://helda.helsinki.fi/bitstream/handle/10138/152906/swimming.pdf?sequence=1

I'll defend my doctoral dissertation on the 30th of January at 12 o'clock noon at lecture hall 2, Infocentre Korona (Viikinkaari 11, Helsinki).

Comment on the image: from what I have heard, it is not given to you actually - you just get the right to buy it.

Parasite of the month

Ophiocordyceps sinensis

This fungus parasitizes the caterpillar of ghost moths (Thitarodes spp.) that live on the Tibetan Plateau and the Himalayas. It infects hosts during the summer, after caterpillars shed their protective coatings and move underground to hibernate. The fungus consumes the host during the hibernation in alpine meadows and produces a stalk-like fruiting body that emerges from the head of the caterpillar in the early spring.  The germination process leads to the death and mummification of the larvae. During this process, infected larvae tend to remain vertical to the soil surface with the heads up. This facilitates germination and dissemination of the spores by the fungus.

The fruiting body of this fungus is used as herbal remedy to cure several diseases, especially those related to lungs, kidneys, and erectile dysfunction. The oldest reference to its use in medicine dates from the 15th century. Overharvesting for these means has led to the rarefaction of the fungus. It is now classified as endangered species. Yet, the fungus is still being sold in Asia and its price can reach up to 65 700€ per kg - quite an expensive Christmas gift...