Collosphaera globularis
Diagnosis
A colonial radiolarian consisting of numerous radiolarian cells and their dinoflagellate symbionts enclosed within the translucent wall of a hollow gelatinous spheroid. Each radiolarian cell is surrounded by a finely porous, siliceous shell which segregates the host cell body from the zooxanthellae in the peripheral ectoplasm. A large lipid body occurs in the center of each radiolarian cell and is surrounded by a layer of endoplasm containing numerous nuclei with cord-like strands of chromatin, tubular cristae mitochondria, and endoplasmic reticulum. The zooxanthellae are sequestered in large vacuoles within the rhizopodial network. Positive evidence for host assimilation of photosynthetically derived organic substances is presented and may partially explain the remarkable abundance of these organisms in oligotrophic regions of the ocean.
Original description
Observation site(s)
SYMBIONTS
Association with... | Region origin | Name of site | In reference... |
---|---|---|---|
Symbiodinium sp. | Bermuda | Castle Harbor |
Fine structure of a symbiont-bearing colonial radiolarian, Collosphaera globularis, and 14C isotopic evidence for assimilation of organic substances from its zooxanthellae. Journal of Ultrastructure Research 62:181 - 189. doi: 10.1016/S0022-5320(78)90031-X (1978) |