Our investigation of saprobic marine fungi in India, Thailand, Sweden and the UK yielded 57 species accommodated in 26 families. In the present study, we describe two new genera, 37 new species and 15 new host records. Novel genera, Halocryptosphaeria and Halotestudina are introduced within Diatrypaceae (Xylariales) and Testudinaceae (Pleosporales), respectively. The new species, Amarenographium ammophilicola, Asterodiscus mangrovei, Boeremia maritima, Chaetopsina aurantisalinicola, Chloridium salinicola, Coniochaeta arenariae, C. krabiensis, Diaporthe krabiensis, D. marina, D. salinicola, Dictyosporium marinum, Dyfrolomyces neothailandicus, Fusicolla gigantispora, Halorosellinia krabiensis, H. xylocarpi, Halotestudina muriformis, Hypoxylon aurantium, H. mangrovei, Lasiodiplodia krabiensis, Nectria marina, Nemania phetchaburiensis, N. viridis, Neocamarosporium artemisiae, N. maritimae, Neocosmospora rhizophorae, Nigrograna samueliana, N. rhizophorae, Patellaria apiculatae, Periconia salina, Peroneutypa indica, P. polysporae, Phaeoseptum carolshearerianum, P. manglicola, Rhytidhysteron bruguierae, Rimaconus multiguttulatus, Salsuginea rhizophorae and Xenoacremonium brunneosporum are introduced based on multigene analyses and morphological studies. This study also provides insights into the diversity of fungi from marine based habitats and confirm that they occupy diverse marine niches. We also demonstrate how marine based substrates, including sand dunes, are fascinating substrates for discovering novel taxa. All taxa described herein are based on morphological examination of fresh specimens supported by multigene phylogenies to better integrate taxa into higher taxonomic framework and infer their phylogenetic relationships as well as establish new species.
