Evidence, based on the species and high rank taxa composition and level of domination, skeletal morphological diversity and distributional data of radiolaria from sediment samples, is presented in support of a hypothesis of endemism for the Arctic polycystine

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

Two major patterns of shell morphogenesis occurring in varying proportions among species were identified by examining skeletons from five species of living collosphaerid, colonial Radiolaria: Collosphaera huxleyi, Acrosphaera cyrtodon, Acrosphaera spinosa,

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