An annotated checklist of myxomycetes from the Seychelles Islands, Indian Ocean

Abstract

The checklist provided herein contains 143 species and infra-specific taxa of myxomycetes representing six orders, 12 families and 29 genera known from the Seychelles Islands. These records are the result of 878 field collections and 468 samples processed with the use of the moist chamber techinque. The overall study involved expeditions to the granitic group of islands Mahé, Praslin, La Digue, Curieuse, Félicité, and data from the literature for the coral Aldabra atoll. The taxonomic structure of the myxomycete biota for the islands studied indicates a predominance of members of the order Physarales (74 taxa). Th e main genera are <em>Physarum</em> (38 species and two varieties), <em>Didymium</em> (17 species), <em>Cribraria</em> (11 species), <em>Arcyria</em> (eight species) and <em>Stemonitis</em> (six species and two varieties). For all six islands only a single species of myxomycete (<em>Physarum crateriforme</em>) was shared in common. For the total assemblage of species recorded from all of the islands, 4% species were abundant, 12% species were common, 29% were found occasionally, 42% were rare, and 13% species had only a single record. The most abundant species were <em>Arcyria cinerea</em>, <em>A. denudata</em>, <em>Diderma effusum</em>, <em>Hemitrichia calyculata</em>, <em>Physarum compressum</em>, and <em>P. melleum</em>. Based on data from 50 different localities with 90 collecting plots, 32% of all specimens were associated with coastal vegetation, 30% with lowland localities, 19% with intermediate forests, 9% with riverine forests, 8% with mountain forests, and only 2% with mangrove swamps. In general, this annotated checklist clearly shows that isolated tropical islands can support a diverse assemblage of myxomycetes.

Past and Ongoing Field-Based Studies of Myxomycetes

“…Elevation appeared to have some effect on the distribution of species on Mahé Island, with compositional differences noted for the assemblages recorded at lower, middle, and higher elevations. Rare species collected during their surveys included Cribraria pachydictyon , Echinostelium paucifilum , and Physarum atroviolaceum [ 55 , 56 , 57 ].…”