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oai:ir.kagoshima-u.ac.jp:00008318 2026-03-03T12:01:20Z 228:257:5552 32:77

Larger Foraminifera : Microscopical Greenhouses Indicating Shallow-Water Tropical and Subtropical Environments in the Present and Past HOHENEGGER, Johann open access Larger Foraminifera with test sizes from 2mm up to 13cm are characteristic organisms inhabiting shallow water subtropical and tropical environments today. They prefer clear, nutrition depleted water as can be found in the surroundings of coral reefs. Two main factors acting as single gradients regulate the distributions of larger foraminifers within coral reef complexes. All living larger Foraminifera house symbiotic microalgae and are thus restricted to the photic zone (down to 150m), getting independence from food resources outside the cell in various degrees. Differences in water movement, mostly correlated with substrate type, and light availability are managed in various ways. Test constructions in combination with attachment mechanisms of the protoplasm combat strong water movement, while light penetration is handled by test ultrastructure. Larger foraminifers inhabiting intertidal and extremely shallow subtidal environments block high irradiation by thicker tests or porcelaineous structures, making the walls impenetrable. In contrast, species living near the base of the photic zone facilitate light penetration by thin transparent test walls facilitating light penetration and by developing light-collecting mechanisms such as nodes and pillars. Water turbulence, often extreme in coral reef environments, is handled in different ways, but tests are restricted to a few paradigmatic forms. Similar tests were developed in various phylogenetic lines at different climatic climaxes during earth history starting from the Late Paleozoic (325,000,000 years ago). This can be interpreted as analogous developments in handling the main environmental gradients light penetration and water energy. 鹿児島大学 Kagoshima University 1999-07-30 eng departmental bulletin paper VoR http://hdl.handle.net/10232/16923 https://ir.kagoshima-u.ac.jp/records/8318 http://hdl.handle.net/10232/16919 13450441 AN1013531X 南太平洋海域調査研究報告 Occasional papers 32 19 45 https://ir.kagoshima-u.ac.jp/record/8318/files/AN1013531X_v32_p19-45.pdf application/pdf 10.2 MB 2016-10-28 1999-07-30