. Advances in marine biology: volume 17. Coral fisheries. ECOLOGY AND TAXONOMY OF Holimeda 195 released carbon dioxide lowers the pH and concentration of carbonate ions in the spaces, inhibiting calcification. Before light stimulation of calcification can occur the photosyn- thetic rate must exceed a certain threshold value (Borowitzka and Larkum, 1976b), and the rate of carbon dioxide removal by photosyn- thesis from the spaces must exceed, by a certain factor, the supply entering the spaces. A model of this scheme is shown in Fig. 60. C07+ H^ X Sea water H^ + HCO3 H, + CO, \ \''n Ca^* 1 ' ^
. Advances in marine biology: volume 17. Coral fisheries. ECOLOGY AND TAXONOMY OF Holimeda 195 released carbon dioxide lowers the pH and concentration of carbonate ions in the spaces, inhibiting calcification. Before light stimulation of calcification can occur the photosyn- thetic rate must exceed a certain threshold value (Borowitzka and Larkum, 1976b), and the rate of carbon dioxide removal by photosyn- thesis from the spaces must exceed, by a certain factor, the supply entering the spaces. A model of this scheme is shown in Fig. 60. C07+ H^ X Sea water H^ + HCO3 H, + CO, \ \''n Ca^* 1 ' ^ t\ -r-rrr-. Fig. 60. A model of calcification in Halimeda, which takes place within the spaces of the segn:ient. These spaces are seiDarated, in most species, from the outer seawater environment by a fusing or adhering of the covering lamellae of adjacent peripheral utricles. The extent of the adhesion depends on the species and somewhat on the age of the material. The postulated movements and fluxes of ions during photo- synthesis, which takes j)lace within the jDerijDheral utricles and to a lesser extent in the remainder of the filament system of the segment, are shown. These include a light-stimulated proton flux. The end result is the precipitation of calcium carbonate in the interutricular and interfilamental spaces of the segments. Black dots at the plasmalemma indicate fluxes postulated to be active. (Modified from Borowitzka, 1977.) 4. Progress in calcification studies: a review Calcification, although not widespread among algae, occurs regu- larly in over 100 genera. The calcium carbonate crystals are deposited. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Hillis-Colinvaux, Liewellya. London : Academic Press ; Toronto
Size: 1896px × 1318px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksponsorbiodiver
