Molecular and developmental effects of invertebrate feeding groups on lake sturgeon eggs and larvae

Session: Application of Genomic Tools to Inform Management of the Great Lakes (5)

Kim Scribner, Dept. Fisheries and Wildlife, Michigan State, [email protected]
Ryan Walquist, Simon Frazer University, [email protected]
John Bauman, Michigan Department of Natural Resources, [email protected]
Terence Marsh, Michigan State University, [email protected]
Jeannette Kanefsky, Michigan State University, [email protected]

Abstract

Effects of macroinvertebrate functional feeding groups (FFGs) on early life development and survival of fish are unknown. Lake Sturgeon spawning habitats and substrates occupied by benthic macroinvertebrates overlap, suggesting species interactions across trophic levels are common. Lake Sturgeon eggs were incubated in five FFG experimental treatments including: predators (Perlidae), facultative-scrapers (Heptageniidae), obligate-scrapers (Helicopsychidae), filterers (Isonychiidae), and no invertebrates controls. We quantified effects of FFGs on egg size, incubation time to hatch, larval body size, resource utilization, percent survival to hatch, and  species composition and abundance of egg surface microbial communities. Eggs exposed to predators were of smaller size, had shorter incubation periods, and lower survival relative to controls. Larvae from eggs exposed to predators had smaller yolk sacs and lengths relative to controls. 16S quantitative (q)PCR estimates of bacterial copy number on egg surfaces varied significantly among  treatments. Metabarcoding interrogation of egg surface bacterial (16S) and lower eukaryotic (18S) communities indicated 16S bacterial diversity varied significantly among invertebrate treatments, while 18S diversity did not vary. Relative sequence abundance of destructive Saprolignia varied significantly among treatments. Interactions between eggs and larvae and macroinvertebrates directly and indirectly through modifications of microbial community abundance and diversity contribute to variability in Lake Sturgeon recruitment.