The roles of endolithic fungi in bioerosion and disease in marine ecosystems. II. Potential facultatively parasitic anamorphic ascomycetes can cause disease in corals and molluscs

Abstract

Anamorphic ascomycetes have been implicated as causative agents of diseases in tissues and skeletons of hard corals, in tissues of soft corals (sea fans) and in tissues and shells of molluscs. Opportunist marine fungal pathogens, such as Aspergillus sydowii, are important components of marine mycoplankton and are ubiquitous in the open oceans, intertidal zones and marine sediments. These fungi can cause infection in or at least can be associated with animals which live in these ecosystems. A. sydowii can produce toxins which inhibit photosynthesis in and the growth of coral zooxanthellae. The prevalence of many documented infections has increased in frequency and severity in recent decades with the changing impacts of physical and chemical factors, such as temperature, acidity and eutrophication. Changes in these factors are thought to cause significant loss of biodiversity in marine ecosystems on a global scale in general, and especially in coral reefs and shallow bays.

Seasonal Variations in the Culturable Mycobiome of Acropora loripes along a Depth Gradient

“…The ecological significance of the coral mycobiome is far from understood, even though various roles of fungi in the marine environment have been proposed [28,29]. The present study is the first case where A. loripes has been examined for the presence of fungi.…”

Global distribution and diversity of marine euendolithic cyanobacteria

“…Bioerosion also occurs through the actions of heterotrophic microorganisms, as well as sponges, invertebrates, and the vertebrates that feed on them. The process of bioerosion plays an important role in both local (e.g., coral reefs) and global biogeochemical cycles (Schneider and Le Campion-Alsumard 1999, Tribollet 2008, Gleason et al 2017a, 2017b. Euendoliths are also important primary producers (Tribollet 2008) that contribute significantly to the cycling of nutrients, especially carbon and nitrogen, in nearshore marine waters (Tribollet et al 2006, Pfister et al 2010.…”

“…The damage caused by euendoliths weakens the structural integrity of the substratum, which increases the costs of repair and maintenance for host organisms (Kaehler and McQuaid 1999, Day et al 2000, Zardi et al 2009, Curin et al 2014) and increases erosion rates of carbonate coastlines (Donn and Boardman 1988). For living organisms, boring also increases the chance of lethal damage from shell collapse, predation, or physical impacts (Webb andKorrubel 1994, Kaehler andMcQuaid 1999), as well as vulnerability to disease (Gleason et al 2017a). The euendolithic lifestyle is found across a wide range of organisms, including fungi, green and red algae, cyanobacteria, and sponges (Gektidis et al 2007, Cockell and Herrera 2008, Sch€ onberg and Wisshak 2012, Murphy et al 2016, Gleason et al 2017b).…”

“…For living organisms, boring also increases the chance of lethal damage from shell collapse, predation, or physical impacts (Webb and Korrubel 1994 , Kaehler and McQuaid 1999 ), as well as vulnerability to disease (Gleason et al. 2017a ). The euendolithic lifestyle is found across a wide range of organisms, including fungi, green and red algae, cyanobacteria, and sponges (Gektidis et al.…”