COX1 metabarcoding of diplostomid brain infection in Eurasian perch

We applied targeted DNA metabarcoding to characterize the eye fluke communities infecting the brain and eye of Eurasian perch (Perca fluviatilis) in seven temperate lakes. This library includes 251 samples from 181 fish divided into three different categories: brain-infected individuals (n=70); eyes of brain-infected individuals (n=70); and eyes of individuals without brain infection (n=111). Each sample was replicated two times and each replicate was tagged with a unique index combination ( files are already demultiplexed and linked to the DNA sample). We found that two frequent eye-infecting parasite species (T. clavata, D. baeri) are also present in the brain of perch and we suggest that the main driver of brain infection is a density-dependent spillover of non-cystic parasites to an alternate location and not the consequence of niche expansion