Discovery of a silicate rock-boring organism and macrobioerosion in fresh water

Ivan N Bolotov,J Bruce H Shyu,Christopher J Glasby,Than Win,Kitti Tanmuangpak,Artyom A Lyubas,Andrey Yu Bychkov,Sakboworn Tumpeesuwan,Mikhail Yu Gofarov,Olga V Aksenova,Alexander V Kondakov,Agniya M Sokolova,Yu Wang,Ilya V Vikhrev,Manuel Lopes-Lima,Torkild Bakken,Oleg S Pokrovsky,Ekaterina S Konopleva

doi:10.1038/s41467-018-05133-4

Abstract

Macrobioerosion is a common process in marine ecosystems. Many types of rock-boring organisms break down hard substrates, particularly carbonate rocks and calcareous structures such as dead corals and shells. In paleontology, the presence of rocks with boreholes and fossil macroboring assemblage members is one of the primary diagnostic features of shallow marine paleo-environments. Here we describe a silicate rock-boring organism and an associated community in submerged siltstone rock outcrops in Kaladan River, Myanmar. The rock-boring mussel Lignopholas fluminalis is a close relative of the marine piddocks, and its borings belong to the ichnospecies Gastrochaenolites anauchen. The neotectonic uplift of the area leading to gradual decrease of the sea level with subsequent shift from estuarine to freshwater environment was the most likely driver for the origin of this community. Our findings highlight that rocks with macroborings are not an exclusive indicator of marine paleo-ecosystems, but may also reflect freshwater habitats.

Highlights

Macrobioerosion is a common process in marine ecosystems
We present the discovery of a rock-boring bivalve species and associated hard substrate community in fresh water
Only a few records of carbonate microbioerosion structures have been described, i.e., micro-borings in mollusc shells associated with a group of minute shell-boring polychaetes[25,26]

Summary

Introduction

Macrobioerosion is a common process in marine ecosystems. Many types of rock-boring organisms break down hard substrates, carbonate rocks and calcareous structures such as dead corals and shells. Bioerosion is a process by which a living organism incises or bores different hard substrates (e.g. rocks, shells, corals, and bones) by mechanical disruption and/or chemical decomposition[1]. Bioerosion increases species diversity of marine hard substrate communities by increasing habitat complexity or as a result of the increase in accessible surface area for colonization[3]. This process influences the evolution of coastal profiles over long timescales[4,5]. Almost all macroborings are recorded in calcareous substrates, e.g., corals, shells, and carbonate rocks[10,21]. Several recent gastropods and sipunculan worms may produce Gastrochaenolites[9]

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Results

Conclusion