The ultrastructure of Gymnosphaera albida Sassaki, a marine axopodiate protozoon

Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
W C Jones


Gymnosphaera albida has been found on the sponge Sycon ciliatum in the Menai Straits, North Wales, during the months of May to December. It commonly adopts a sedentary mode of life when cultured, settling with its body in contact with the substratum and its axopodia radiating upwards and outwards all round. At times it floats freely. When sessile it can displace itself, but not by rolling. It is a voracious carnivore. The largest seen had a body size of 510 mum X 320 mum. The body of Gymnosphaera is divided into three zones: a central medulla, a cortex and a superficial reticulated pseudopodial layer. The medulla is finely vacuolated and contains an axoplast at its centre. The cortical cytoplasm contains many nuclei, Golgi bodies, polysomes, mitochondria, osmiophilic globules, lipoid spherules and vacuoles of various kinds, but no zooxanthellae. The superficial reticulated pseuopodial layer contains osmiophilic globules and occasional mitochondria. Axonemes radiate from the axoplast to the axopodia, along which osmiophilic globules are generally in motion. In between the cortex and the reticulated pseudopodial layer there is a narrow, extracytoplasmic capsular wall (Sassaki's line), consisting of a microfibrillar coagulum. The ...Continue Reading


Aug 1, 1975·Cell and Tissue Research·C F Bardele
Nov 1, 1972·The American Journal of Roentgenology, Radium Therapy, and Nuclear Medicine·W H ShufordD Brinsfield

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