Hosts pay energetic costs to parasites even before infection is established

Ryan Hechingernews

In a paper just published in Functional Ecology coming from Lauren’s postdoc work, we report that attacking Euhaplorchis californiensis (Euha) cercariae prompt killifish to become more active and burn more calories. This likely represents that the fish can sense the attacking parasites and then seek to defend against successful infection. Intriguingly, the overall metabolic rates of killifish that already had Euha on the brain were indistinguishable from uninfected fish, suggesting that the main energy drain caused by the parasite might arise from the attacking stages, not the actual feeding stages. See our press release and the paper for the whole story.



Jennifer defends her MS thesis!

Ryan Hechingernews

Jennifer Dusto today successfully defended her BS/MS thesis, which involves describing the first mermithid parasitoid known to infect crabs.

Congrats Jennifer!

Cassie defends her MS thesis!

Ryan Hechingernews

Cassandra Bernas today defended her BS/MS thesis dealing with using DNA sequences to reveal cryptic diversity of parasites in our food webs, and to connect up different life stages of those parasites.

Congrats Cassie!

Trematode parasites make more soldiers in areas of greater invasion threat

Ryan Hechingernews

That’s the main finding we report in a new Biology Letters pub with collaborators Emlyn Resetaritz and Mark Torchin.

Remarkably, this seems to be the first robust documentation for any animal society of a spatial relationship between allocation to a specific caste and the supposed selective agent. Again showing the power of using trematodes as model systems to tackle fundamental ecological, evolutionary, & behavioral questions.

Congrats to Emlyn who did this work for her PhD thesis as a visiting graduate student at SIO (California) and at STRI (Panama)!

link to pub

Euhaplorchis prefers two areas of killifish brains

Ryan Hechingernews

In a new collaborative paper, we present the distribution of the brain-infecting host-behavior-modifying Euhaplorchis californiensis (Euha) parasite along the antero-posterior axis of California killifish brains. We find that, although Euha metacercariae cover the whole brain, they are really dense in two areas. The density peaks provide clues to the route of parasite entry into the brain and the neurological mechanisms underlying the parasite’s manipulation of host behavior. This work was part of Siri Helland-Riise’s thesis, who spent many many months with us as part of our collaboration with Oyvind Overli and Kelly Weinersmith. link to paper