EXTRACELLULAR STRUCTURES PRODUCED BY MARINE SPECIES OF MASTOGLOIA

Diatom taxa of the genus Mastogloia collected near Lee Stocking Island, Bahamas and in Shark Bay, Australia were observed to produce extracellular structures. The shape, arrangement, and number of these structures is species-specific and related to the number of partecta. Structures observed in 20 Mastogloia taxa included striated hollow cylinders, smaller diameter strands and fibers, pads and capsules. In some instances, these secretions clearly function as an attachment mechanism for the diatom and also facilitate the trapping and binding of carbonate grains for stromatolite growth. Staining and x-ray emission analysis were inconclusive in determining the chemical composition of these structures.