A study of the vertical zonation of intertidal fungi on Rhiziphora apiculata at Kampong Kapok mangrove, Brunei

Decayed samples of Rhizophora apiculata Blume were collected from various tidal levels in Kampong Kapok mangrove, Brunei and examined for higher marine fungi. Fifty-seven species were recorded; this represents the greatest number of intertidal fungi known from a single species of mangrove tree. Trichocladium cf. opacum (Corda) Hughes (17.75%) was most common, while Xylomyces sp. (13%), Cirrenalia pygmea Kohlm. (12.75%), Lulworthia sp. (12.75%), Leptosphaeria australiensis (Cribb & Cribb) Hughes (10.5%) and Thalassogena sphaerica Kohlm. & Volkm.-Kohlm. (8%) were also recorded frequently. The fungi were found to be vertically zonated; some were limited to the upper (e.g. Hypoxylon oceanicum Schatz, Savoryella lignicola Jones & Eaton) or lower (e.g. Antennospora quadricornuta (Cribb & Cribb) Johnson, Thalassogena sphaerica) levels, while only two (Cirrenalia pygmea and Lulworthia sp.) were present throughout the tidal range. The greatest number of species were collected from above mean tide (notably Level 3). Fungi with certain characteristics were also limited to vertical zones (e.g. those with arbonaceous walls only occurred above mean tide).