Fungi associated with mesophotic macroalgae from the 'Au'au Channel, west Maui are differentiated by host and overlap terrestrial communities.

Anthony S Amend,Alison R Sherwood,Celia M Smith,Heather L Spalding,Geoffrey L Zahn,Benjamin J Wainwright

doi:10.7717/peerj.3532

Abstract

Mesophotic coral ecosystems are an almost entirely unexplored and undocumented environment that likely contains vast reservoirs of undescribed biodiversity. Twenty-four macroalgae samples, representing four genera, were collected from a Hawaiian mesophotic reef at water depths between 65 and 86 m in the ‘Au‘au Channel, Maui, Hawai‘i. Algal tissues were surveyed for the presence and diversity of fungi by sequencing the ITS1 gene using Illumina technology. Fungi from these algae were then compared to previous fungal surveys conducted in Hawaiian terrestrial ecosystems. Twenty-seven percent of the OTUs present on the mesophotic coral ecosystem samples were shared between the marine and terrestrial environment. Subsequent analyses indicated that host species of algae significantly differentiate fungal community composition. This work demonstrates yet another understudied habitat with a moderate diversity of fungi that should be considered when estimating global fungal diversity.

Highlights

Mesophotic coral ecosytems (MCEs) remain an almost entirely unexplored and undocumented environment that likely contains vast reservoirs of undescribed biodiversity (Pyle et al, 2016; Baker, Puglise & Harris, 2016)
Because we are interested in marine fungal contributions to global fungal diversity, our study focuses on determining the extent to which host identity and spatiotemporal variables correlate with fungal community composition at small spatial scales
39 OTUs were shared between the two ecosystems, they displayed different patterns of abundance (Fig. 4; Tables S5 & S6). 17 OTUs were found in all samples collected from MCEs, of these only one was shared between MCE and Fungal foliar epiphyte (FFE) (Table S7)

Summary

Introduction

Mesophotic coral ecosytems (MCEs) remain an almost entirely unexplored and undocumented environment that likely contains vast reservoirs of undescribed biodiversity (Pyle et al, 2016; Baker, Puglise & Harris, 2016). Little is known of the biodiversity, community composition and importance of these MCEs. The application of mixed gas, closed circuit (Rebreather) diving techniques along with Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs) are making exploration of these understudied areas of the ocean possible (Pyle, Earle & Greene, 2008; Bridge et al, 2011). The application of mixed gas, closed circuit (Rebreather) diving techniques along with Remotely Operated Vehicles (ROVs) and Autonomous Underwater Vehicles (AUVs) are making exploration of these understudied areas of the ocean possible (Pyle, Earle & Greene, 2008; Bridge et al, 2011)

Methods

Results

Conclusion