Ultrastructure of siliceous spicules and micro sclerocytes in the marine sponge neofibularia irata new species
Wilkinson, C.R.; Garrone, R.
Journal of Morphology 166(1): 51-64
ISSN/ISBN: 0362-2525 Accession: 006863069
The marine sponge N. irata contains 4 different categories of siliceous spicules. These spicules are evident in the tissues as distinct bundles that act to increase the structural rigidity of the sponge. All spicules have a normal structural morphology with silica deposition around a hexagonal axial canal containing a crystalline axial filament. The megasclere strongyles are secreted in typical megasclerocytes. The sigma and raphid microscleres are secreted in individual microsclerocytes that are grouped together in parallel to form loose bundles. The microxea microscleres are apparently secreted in distinct tight bundles (trichodragmas) within a single cell. These cells, containing between 13 and 39 spicules, are grouped to form large packets of bundles of spicules.