Multi-scale ecological filters shape the crayfish microbiome

Biology, Virginia Tech, Blacksburg, VA, USA
Department of Biology, Indiana University, Bloomington, Indiana, United States
Department of Biology, Appalachian State University, Boone, North Carolina, United States
DOI
10.7287/peerj.preprints.2266v1
Subject Areas
Biodiversity, Biogeography, Ecology, Microbiology, Parasitology
Keywords
bacteria, branchiobdellida, cleaning symbiosis, defensive symbiosis, disease ecology, metacommunities, parasites, cambarus, symbiosis
Copyright
© 2016 Skelton et al.
Licence
This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
Cite this article
Skelton J, Geyer KM, Lennon JT, Creed RP, Brown BL. 2016. Multi-scale ecological filters shape the crayfish microbiome. PeerJ Preprints 4:e2266v1

Abstract

Communities of symbiotic microbes obtained from the environment are an integral component of animal fitness and ecology. Thus a general and practical understanding of the processes that drive microbiome assembly and structure are paramount to understanding animal ecology, health, and evolution. We conceptualized a series of ecological filters that operate at the environment, host, and host tissue levels during microbiome assembly and discuss key ecological processes that structure animal microbiomes at each level. We conducted a survey of crayfish across four sites within the contiguous range of the of stream-inhabiting crayfish Cambarus sciotensis in western Virginia, USA, to characterize multiscale variation in the crayfish microbiome. We also conducted an in situ experiment to assess local drivers of microbial diversity on the closely related Cambarus chasmodactylus. We used a combination of DNA fingerprinting and next-generation sequencing to characterize microbiome diversity and composition from crayfish carapaces and gills to identify key filters affecting microbiome structure. Field survey showed that local environment and host tissues interact to create patterns of microbial diversity and composition, but the strongest effects on microbial community structure were observed at the level of host tissue. Our field experiment confirmed strong effects of host tissue, and also showed that a metazoan ectosymbiont which feeds on biofilms (Annelida; Branchiobdellida) had significant effects on microbial composition of the host carapace. Crayfish carapaces were colonized by diverse and taxonomically even microbial communities that were similar to, and correlated with, microbial communities of the ambient environment. Conversely, crayfish gills were colonized by less diverse communities and dominated by two families of bacteria with potentially significant functional roles: Comamonadaceae and Chitinophagaceae. Our results suggest that microbial assembly of the carapace is driven by external biotic and abiotic processes, whereas assembly on the gills appears to be coupled to host biology that favors interactions with few specific taxa. Our work shows how multi-scale studies of symbiont community assembly provide valuable insights into how the animal microbiome is structured under conditions of natural complexity and help identify other symbiont taxa, i.e., the branchiobdellidans, that may further influence microbiome assembly and structure.

Author Comment

This manuscript is currently in preparation for submission to a peer reviewed journal.

Supplemental Information

Standardized peaks from TRFLP analysis

DOI: 10.7287/peerj.preprints.2266v1/supp-1

Fasta file of OTU sequences from Illumina run

DOI: 10.7287/peerj.preprints.2266v1/supp-2

Sample by OTU matrix from Illumina sequerncoing of field experiment samples

DOI: 10.7287/peerj.preprints.2266v1/supp-3

Sample treatments and supporting information

DOI: 10.7287/peerj.preprints.2266v1/supp-4