Community structure and diversity of marine ascomycetes from coastal beaches of the southern Gulf of Mexico Patricia VELEZ a, *, Mar  ıa C. GONZ  ALEZ a , Edmundo ROSIQUE-GIL b , Joaqu  ın CIFUENTES c , Mar  ıa del Roc  ıo REYES-MONTES d , Silvia CAPELLO-GARC  IA b , Richard T. HANLIN e a Instituto de Biolog  ıa, Universidad Nacional Aut onoma de M exico, Apartado Postal 70-233, M exico D. F. 04510, Mexico b Divisi on Acad emica de Ciencias Biol ogicas, Universidad Ju arez Aut onoma de, Tabasco, Villahermosa, Tab. 86039, Mexico c Facultad de Ciencias, Universidad Nacional Aut onoma de M exico, M exico D. F. 04510, Mexico d Facultad de Medicina, Universidad Nacional Aut onoma de M exico, M exico D. F. 04510, Mexico e Museum of Natural History Annex, University of Georgia, Bogart, GA 30622, USA article info Article history: Received 12 June 2013 Revision received 18 September 2013 Accepted 24 September 2013 Available online 9 November 2013 Corresponding editor: Felix B€ arlocher Keywords: Arenicolous fungi Intertidal environment Multivariate statistics Sandy beach ecology Saprotroph abstract Diversity of marine fungi in the Gulf of Mexico remains unknown for the most part, therefore the geographical distribution patterns of these microorganisms are mostly unknown too. Twelve sandy beaches located in this sea were sampled to evaluate the diversity of marine fungi, revealed by fruiting on natural substrata incubated in the labo- ratory for up to 12 months. Species richness and diversity differed between beaches, and corresponded with the presence of main and highly polluted river mouths, nearshore marine environments, and core industrial and port developments. Contaminants and local anthropogenic activities may be reducing the diversity of marine ascomycetes. Con- nections between beaches and different nearshore habitats explain the high diversity observed, since they represent a varied source of substrata for decomposition and heter- ogeneous environmental conditions. We recognized four main local species distribution patterns. Moreover, the constrained correspondence analysis showed that temperature is a major environmental variable affecting the distribution of these fungi. By a linear regres- sion we showed a significant relationship between temperature and diversity. ª 2013 Elsevier Ltd and The British Mycological Society. All rights reserved. Introduction Marine ascomycetes are an important component of bio- diversity in sandy beaches. This group of fungi represents an ecological assemblage of mostly saprotrophic microorganisms that play an active role in the ecological function of sandy beach marine ecosystems (Kohlmeyer and Kohlmeyer, 1979; Hyde et al., 2000; Sakayaroj et al., 2004). These saprobes occur on dif- ferent substrata rich in lignin, cellulose, or chitin (e.g., calcareous molluscan and crustacean exoskeletons, plant material asso- ciated with sand grains on beaches, drift wood, algae and sea- weeds, sea grasses, and roots, stems, leaves, fruits, seeds of * Corresponding author. Tel.: þ52 55 562 29136; fax: þ52 55 5550 1760. E-mail address: pvelez@st.ib.unam.mx (P. Velez). available at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/funeco 1754-5048/$ e see front matter ª 2013 Elsevier Ltd and The British Mycological Society. All rights reserved. http://dx.doi.org/10.1016/j.funeco.2013.10.002 fungal ecology 6 (2013) 513 e521