Volume 66, Issue 4 - Special Issue: Whither marine mycology: the way forward; Issue Editors: Ka-Lai Pang and E. B. Gareth Jones

This article revises the documented diversity of known marine fungi from nine phyla, 33 classes, 107 orders, 273 families, 767 genera and 1898 species reported worldwide. A member of the Aphelidiomycota, Pseudaphelidium drebesii , is reported for the first time from the marine environment, on a diatom. Likewise, the phylum Mortierellomycota is listed following taxonomic changes, as are six subclasses: Chaetothyriomycetidae, Savoryellomycetidae, Sclerococcomycetidae, Agaricostilbomycetidae, Auriculariomycetidae and Aphelidiomycotina. Thirty-three orders and 105 family names with marine species are added to the checklist, along with 641 species in 228 genera, bringing the total to 1898. New additions of species added to the list of marine fungi are highlighted. Four new combinations are proposed: Stigmatodiscus mangrovei , Diaporthe krabiensis and Diaporthe xylocarpi , while the hyphomycete Humicola alopallonella is referred to the genus Halosphaeriopsis , as Halosphaeriopsis alopallonella.

Early research on marine fungi was mostly descriptive, with an emphasis on their diversity and taxonomy, especially of those collected at rocky shores on seaweeds and driftwood. Subsequently, further substrata (e.g. salt marsh grasses, marine animals, seagrasses, sea foam, seawater, sediment) and habitats (coral reefs, deep-sea, hydrothermal vents, mangroves, sandy beaches, salt marshes) were explored for marine fungi. In parallel, research areas have broadened from micro-morphology to ultrastructure, ecophysiology, molecular phylogenetics, biogeography, biodeterioration, biodegradation, bioprospecting, genomics, proteomics, transcriptomics and metabolomics. Although marine fungi only constitute a small fraction of the global mycota, new species of marine fungi continue to be described from new hosts/substrata of unexplored locations/habitats, and novel bioactive metabolites have been discovered in the last two decades, warranting a greater collaborative research effort. Marine fungi of Africa, the Americas and Australasia are under-explored, while marine Chytridiomycota and allied taxa, fungi associated with marine animals, the functional roles of fungi in the sea, and the impacts of climate change on marine fungi are some of the topics needing more attention. In this article, currently active marine mycologists from different countries have written on the history and current state of marine fungal research in individual countries highlighting their strength in the subject, and this represents a first step towards a collaborative inter- and transdisciplinary research strategy.

Neocamarosporium aquaticum , collected from a drift dead stem of a halophyte at the Kench Nature Reserve, Hayling Island, UK, is described as a new species in the family Neocamarosporiaceae, Dothideomycetes. Multi-locus analyses based on LSU, SSU, ITS rDNA, and EF1-α placed the new fungus as a distinct species in the genus Neocamarosporium , a sister to Neocamarosporium aesturinum isolated from seawater. The new species is characterized by the asexual morph with pycnidial conidiomata, doliiform, enteroblastic, annellidic conidiogenous cells, and conidia that are initially hyaline, aseptate, with longitudinal and transverse septa when matured, muriform, and turning brown to dark brown on maturity. Neocamarosporium aquaticum and Ne. aesturinum differ in the colour of the conidia, degree of septation, and conidial measurements.

This study introduces two new marine microfungal species, Paraloratospora marina (Phaeosphaeriaceae) and Tremateia phragmitis (Didymosphaeriaceae) based on morphological comparisons and multi-gene phylogenetic analyses. They were collected on decaying woody stems of Phragmites australis at Cardiff Bay Nature Reserve in Wales, United Kingdom. Paraloratospora marina sp. nov . is characterized by immersed, globose to subglobose ascomata with a papillate and periphysate ostiole, cylindrical to subcylindrical, thick-walled, sessile to subsessile asci, fusiform, hyaline to pale brown, 3-septate, guttulate ascospores. Tremateia phragmitis sp. nov. is characterized by semi-immersed to immersed, globose ascomata with a protruding periphysate ostiole, clavate, pedicellate, asci and ascospores that are ellipsoidal to broadly fusiform, 4–6 transversely septate, with 1–2 vertical septa, muriform, golden brown to pale brown ascospores. Dichotomopilus funicola and Pseudofusicoccum ardesiacum are recorded for the first time from marine habitats. Furthermore, based on morphological characteristics and multigene phylogenetic analyses, Phaeosphaeria spartinae was transferred to Septoriella .

The fungal community associated with marine crabs is poorly known, except for the fungi causing diseases of marine animals of economic value. In this study we examined the diversity of fungi cultured from carapace and gut of the marine crab Portunus sanguinolentus , and the identification was based on nucleotide BLAST search results of the internal transcribed spacers of rDNA (ITS). A total of 256 fungal isolates representing 23 species were cultured from seven individuals of P. sanguinolentus including two unidentified species. The majority of the species belong to the Ascomycota, while three species of the Basidiomycota were isolated from the gut. Overall, Candida tropicalis (45.70 %, percentage occurrence), Apiotrichum lignicola (8.98 %) and Rhodotorula sp. (8.20 %) were the dominant fungi on the crab. The most dominant fungi on the carapace were C. tropicalis (66.95 %), Emericellopsis maritima (8.47 %), A. lignicola and Purpureocillium lilacinum (both 4.24 %). In the gut, C. tropicalis (27.54 %), A. lignicola (16.67 %), Rhodotorula sp. (15.22 %) and Fusarium solani (14.49 %) were dominant. The fungal diversity in the gut of P. sanguinolentus was higher than on the carapace according to the diversity indices. Although some of the isolated fungi were reported to be pathogenic, none were reported as pathogens of crabs, and no disease symptoms were noticed from the crab samples.

Coral reefs are one of the most biodiverse marine ecosystems. Diverse microbes are associated with corals, including zooxanthellae, protists, prokaryotes, and viruses. This study aimed to investigate the genetic diversity of the culturable fungi associated with scleractinian corals in the Gulf of Thailand. Ribosomal DNA sequence analysis and morphological analysis of 130 fungal isolates revealed a high diversity of fungal phylotypes from three coral species: Pavona decussata , Pocillopora damicornis and Porites lutea . Ascomycota was the most abundant fungal phylum. The predominant orders included Eurotiales, Cladosporiales, Hypocreales, Mycosphaerellales, and Diaporthales. There were eight orders of the Basidiomycota dominated by Polyporales, Hymenochaetales, Agaricales, and Wallemiales. A principal component analysis was performed to compare abundance and correlation between the fungal communities, sampling locations and coral species. The results showed that the dissimilarity of fungal communities corresponded to geographic localities. On the other hand, there was a considerable overlap between the fungal communities of different coral species. The results from this research provide information on the diversity and ecology of the fungal communities associated with scleractinian corals in the Gulf of Thailand.

Marine fungi play an integral role in the decomposition of intertidal organic substrata but remain understudied in cold-water habitats including Atlantic Canada. Marine inundated wood from the intertidal zone was sampled from 30 sites along the Bay of Fundy coastline in Nova Scotia, Canada. Wood types studied included attached and loose intertidal wood, and driftwood. Emergent fungi were cultured and identified using ITS (internal transcribed spacers) rDNA barcoding. Two hundred and twenty cultures representing 86 fungi are reported. Sixty-one fungi were new records for the Bay of Fundy, 41 are first records from the marine environment, and 19 fungi are potentially new to science. Fungi identified included eight obligate marine fungi, with the remaining fungi being facultatively marine. Eight ascomycetes were soft rot fungi; this ecological strategy for decaying woody material in cold-water marine environments is discussed. Historical records and roles of wood type and site on fungal colonization are discussed.

Long-chain polyunsaturated fatty acids (LC-PUFA) are nutritionally and pharmacologically well-recognized beneficial compounds widely used as nutrient supplements for various applications. As the human body cannot accomplish de novo synthesis of PUFA, we depend on exogenous bioresources for the supply of these essential PUFA for day-to-day activities. The PUFA global market is expected to reach about US$ 9.7 billion by 2032. The recent drop in natural fish catch and global climate change severely hamper the global PUFA supply chain. As a sustainable, promising resource, marine zoosporic microorganisms are considered to be safe and alternative primary producers of beneficial PUFAs for direct and indirect human consumption. However, by considering the limitations associated with strain efficiency, final product yield and production cost, more viable low-cost production strategies and establishment of highly efficient, stable, high production cell lines specific for marine zoosporic microbes are essential to meet global PUFA market demand. The exploration of the latest techniques for research and development could shape the dynamics better for the global market for marine zoosporic organism-based PUFA products. Therefore, this review first summarizes low-cost production and strain improvement strategies, and later highlights the advantages and commercial prospects for marine zoosporic microbe-derived PUFA.

Salinity and temperature are two of the key environmental variables influencing the distribution of fungi. Results from the limited research available on the effects of salinity and temperature on growth and reproduction of chytrids were inconclusive. This study investigated the combined effects of salinity (0, 1, 2, 4, 8, 16, 32) and temperature (17, 24, 30 °C) on the growth rate of Alphamyces chaetifer (isolates IMB230, IMB231, IMB232) and Gorgonomyces haynaldii (IMB233, IMB237, IMB239) cultured from low-salinity water samples collected from coastal wetlands/ponds of eastern Taiwan. All isolates grew well at salinity 4 or below, irrespective of the incubation temperatures, although some grew significantly faster at 30 °C. No growth was observed at salinity 16 or 32. At or below 4, A. chaetifer IMB230 and IMB231, isolated from the same collection site where salinity was 2, produced the fastest growth rate at these salinities while G. haynaldii IMB237 and IMB239, isolated from water samples of zero salinity, had the slowest growth rate. These results agree with previous research that chytrids are sensitive to salinity, and may explain why only 27 culturable Chytridiomycota species and allied taxa have been documented from the marine environment.