Skeletogenesis in polycystine radiolarians was detected, using a fluorescent compound called PDMPO (2-(4-pyridyl)–5-[(4-(2-dimethylaminoethylaminocarbamoyl)methoxy)-phenyl] oxazole). This compound binds under acidic conditions with silica in the silica deposition vesicle (SDV) of radiolarians, and o...

The ontogeny of the skeleton of the nassellarian radiolarian Amphimelissa setosa begins with the formation of three radial bars of silica; these correspond to the medial bar and spines L1 and L2 in the adult. By a precise sequence of the addition of various siliceous arcs and spines, this basic stru...

A conceptual analysis of morphogenetic growth patterns in biomineralizing Protista is presented as an organizing perspective for the analysis of skeletal morphogenesis in two species of Radiolaria. This analysis also serves as a rationale for the derivation of a method to quantitatively express the ...

Stages of growth ofSpongaster tetras tetras were observed using scanning electron microscopy. The earliest stage with a diagonal of about 75 to 100 μm is a biconvex, nearly lens-shaped, tabular structure. Subsequent growth by accretion of silica at the periphery produces a more quadrangular tabular ...