Ultrastructural studies of Trematosphaeria malaysiana sp nov and Leptosphaeria pelagica

Trematosphaeria malaysiana sp. nov, is described based on light microscope and ultrastructural studies. It was found on driftwood, exposed test blocks of Avicennia marina and Rhizophora apiculata, and split twigs of R. apicul ata exposed in Kuala Selangor and Morib mangroves, Malaysia. T. malaysiana is characterized by striate, pale brown ascospores and trabeculate pseudopa raphyses. Ascospore cell walls are two layered, an outer thick layer compri sing fibrillar mucilaginous material, and an inner bilamellate layer (the i nner layer electron-transparent : the outer electron-dense and containing m elanin). Both T. malaysiana and Leptosphaeria pelagica were examined at the transmission electron microscope level and their structure compared with t hat of other bitunicate ascomycetes. T. malaysiana and L. pelagica were sim ilar in that the mucilaginous sheath was the outer most layer, in the forme r the spore wall was two layered, while in L. pelagica it was three layered . In L. pelagica the spore wall was smooth, while in T. malaysiana it was l ongitudinally striate.