Peer Review #2 of "Diversity, host-specificity and stability of sponge-associated fungal communities of co-occurring sponges (v0.1)" [peer_review]

T Cernava
2018 unpublished
Fungi play a critical role in a range of ecosystems, however their interactions and functions in marine hosts, and particular sponges, is poorly understood. Here we assess the fungal community composition of three co-occurring sponges (Cymbastela concentrica, Scopalina sp., Tedania anhelans) and the surrounding seawater over two time points to help elucidate host-specificity, stability and potential core members, which may shed light into the ecological function of fungi in sponges. The results
more » ... showed that ITS-amplicon-based community profiling likely provides a more realistic assessment of fungal diversity in sponges than cultivation-dependent approaches. The sponges studied here were found to contain phylogenetically diverse fungi (eight fungal classes were observed), including members of the family Togniniaceae and the genus Acrostalagmus, that have so far not been reported to be cultured from sponges. Fungal communities within any given sponge species were found to be highly variable compared to bacterial communities, and influenced in structure by the community of the surrounding seawater, especially considering temporal variation. Nevertheless, the sponge species studied here contained a few 'variable/core' fungi that appeared in multiple biological replicates and were enriched in their relative abundance compared to seawater communities. These fungi were the same or highly similar to fungal species detected in sponges around the world, which suggests a prevalence of horizontal transmission where selectivity and enrichment of some fungi occur for those that can survive and/or exploit the sponge environment. Our current (sparse) knowledge about sponge-associated fungi thus indicate that fungal communities may perhaps not play as an important ecological role in the sponge holobiont as its bacterial or archaeal symbionts. PeerJ reviewing PDF | Abstract 18 Fungi play a critical role in a range of ecosystems, however their interactions and functions in 19 marine hosts, and particular sponges, is poorly understood. Here we assess the fungal community 20 composition of three co-occurring sponges (Cymbastela concentrica, Scopalina sp., Tedania 21 anhelans) and the surrounding seawater over two time points to help elucidate host-specificity, 22 stability and potential core members, which may shed light into the ecological function of fungi 23 in sponges. The results showed that ITS-amplicon-based community profiling likely provides a 24 more realistic assessment of fungal diversity in sponges than cultivation-dependent approaches. 25 The sponges studied here were found to contain phylogenetically diverse fungi (eight fungal 26 classes were observed), including members of the family Togniniaceae and the genus 27 Acrostalagmus, that have so far not been reported to be cultured from sponges. Fungal 28 communities within any given sponge species were found to be highly variable compared to 29 bacterial communities, and influenced in structure by the community of the surrounding 30 seawater, especially considering temporal variation. Nevertheless, the sponge species studied 31 here contained a few 'variable/core' fungi that appeared in multiple biological replicates and 32 were enriched in their relative abundance compared to seawater communities. These fungi were 33 the same or highly similar to fungal species detected in sponges around the world, which 34 suggests a prevalence of horizontal transmission where selectivity and enrichment of some fungi 35 occur for those that can survive and/or exploit the sponge environment. Our current (sparse) 36 knowledge about sponge-associated fungi thus indicate that fungal communities may perhaps not 37 play as an important ecological role in the sponge holobiont as its bacterial or archaeal 38 symbionts. PeerJ reviewing PDF |
doi:10.7287/peerj.4965v0.1/reviews/2 fatcat:nk5eqcr2ofb5bbbkfuymtxmgya