Uptake of calcium at the postmoult stage by the marine crabs Callinectes sapidus and Carcinus maenas

Carbonic Anhydrase in Mineralization of the Crayfish Cuticle

“…This situation occurs in the membraneous cuticle layer which is not calci ed (Giraud, 1981;Simkiss & Wilbur, 1989). While the source and delivery of calcium ions to the mineralization site seems apparent (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985), the source of carbonate ions has not been so obvious (Roer & Dillaman, 1984), especially at physiological pHs near 7. It is likely that the extracellular CA may be the source of the carbonate via bicarbonate.…”

“…Initiation of calcite formation requires supersaturation of calcium carbonate. If pumping of calcium ions via the hypodermis and epidermal protrusions (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985) into the organic matrix where nucleation sites exist initiates calcite formation, crystal growth would continue as long as both calcium and carbonate ions were available. As one of the components of the organic matrix, CA might assist initiation of mineralization by indirectly maintaining the availability of carbonate ions at the mineralization site.…”

Carbonic Anhydrase in Mineralization of the Crayfish Cuticle

“…This situation occurs in the membraneous cuticle layer which is not calci ed (Giraud, 1981;Simkiss & Wilbur, 1989). While the source and delivery of calcium ions to the mineralization site seems apparent (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985), the source of carbonate ions has not been so obvious (Roer & Dillaman, 1984), especially at physiological pHs near 7. It is likely that the extracellular CA may be the source of the carbonate via bicarbonate.…”

“…Initiation of calcite formation requires supersaturation of calcium carbonate. If pumping of calcium ions via the hypodermis and epidermal protrusions (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985) into the organic matrix where nucleation sites exist initiates calcite formation, crystal growth would continue as long as both calcium and carbonate ions were available. As one of the components of the organic matrix, CA might assist initiation of mineralization by indirectly maintaining the availability of carbonate ions at the mineralization site.…”

Some considerations on calcium homeostasis in semi-terrestrial crabs

“…Ca net flux during postmolt has been studied before in crayfish [1,21] and there are existing reports of first day postmolt fluxes in Carcinus maenas [22] and in Callinectes sapidus [23]. Fluxes range from 3200 Amol kg À1 h À1 for the marine species Carcinus and Callinectes to values as low as 1000 Amol kg À1 h À1 for the crayfish Cherax destructor living in freshwater containing Ca at around 0.2 mmol L À1 .…”

Post-molt processes of cuticle formation and calcification in the Japanese mitten crab Eriocheir japonicus

“…However, there is some evidence indicating the dependence of exoskeletal calcification on environmental calcium levels in other crustacean species. In the blue crab and Atlantic shore crab (both marine species), post-molt calcium uptake from the ambient water is affected by calcium levels [15,16]. In the noble crayfish, Astacus astacus and the amphipod Gammarus lacustris (both freshwater species), a low-calcium environment decreases whole-body calcium content [17].…”

Carbonic Anhydrase in Mineralization of the Crayfish Cuticle

“…This situation occurs in the membraneous cuticle layer which is not calci ed (Giraud, 1981;Simkiss & Wilbur, 1989). While the source and delivery of calcium ions to the mineralization site seems apparent (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985), the source of carbonate ions has not been so obvious (Roer & Dillaman, 1984), especially at physiological pHs near 7. It is likely that the extracellular CA may be the source of the carbonate via bicarbonate.…”

“…Initiation of calcite formation requires supersaturation of calcium carbonate. If pumping of calcium ions via the hypodermis and epidermal protrusions (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985) into the organic matrix where nucleation sites exist initiates calcite formation, crystal growth would continue as long as both calcium and carbonate ions were available. As one of the components of the organic matrix, CA might assist initiation of mineralization by indirectly maintaining the availability of carbonate ions at the mineralization site.…”

Some considerations on calcium homeostasis in semi-terrestrial crabs

“…Ca net flux during postmolt has been studied before in crayfish [1,21] and there are existing reports of first day postmolt fluxes in Carcinus maenas [22] and in Callinectes sapidus [23]. Fluxes range from 3200 Amol kg À1 h À1 for the marine species Carcinus and Callinectes to values as low as 1000 Amol kg À1 h À1 for the crayfish Cherax destructor living in freshwater containing Ca at around 0.2 mmol L À1 .…”

Post-molt processes of cuticle formation and calcification in the Japanese mitten crab Eriocheir japonicus

“…However, there is some evidence indicating the dependence of exoskeletal calcification on environmental calcium levels in other crustacean species. In the blue crab and Atlantic shore crab (both marine species), post-molt calcium uptake from the ambient water is affected by calcium levels [15,16]. In the noble crayfish, Astacus astacus and the amphipod Gammarus lacustris (both freshwater species), a low-calcium environment decreases whole-body calcium content [17].…”

Carbonic Anhydrase in Mineralization of the Crayfish Cuticle

“…This situation occurs in the membraneous cuticle layer which is not calci ed (Giraud, 1981;Simkiss & Wilbur, 1989). While the source and delivery of calcium ions to the mineralization site seems apparent (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985), the source of carbonate ions has not been so obvious (Roer & Dillaman, 1984), especially at physiological pHs near 7. It is likely that the extracellular CA may be the source of the carbonate via bicarbonate.…”

“…Initiation of calcite formation requires supersaturation of calcium carbonate. If pumping of calcium ions via the hypodermis and epidermal protrusions (Roer, 1980;Roer & Dillaman, 1984;Greenaway, 1983;Cameron & Wood, 1985) into the organic matrix where nucleation sites exist initiates calcite formation, crystal growth would continue as long as both calcium and carbonate ions were available. As one of the components of the organic matrix, CA might assist initiation of mineralization by indirectly maintaining the availability of carbonate ions at the mineralization site.…”

Some considerations on calcium homeostasis in semi-terrestrial crabs

“…Ca net flux during postmolt has been studied before in crayfish [1,21] and there are existing reports of first day postmolt fluxes in Carcinus maenas [22] and in Callinectes sapidus [23]. Fluxes range from 3200 Amol kg À1 h À1 for the marine species Carcinus and Callinectes to values as low as 1000 Amol kg À1 h À1 for the crayfish Cherax destructor living in freshwater containing Ca at around 0.2 mmol L À1 .…”

Post-molt processes of cuticle formation and calcification in the Japanese mitten crab Eriocheir japonicus

“…However, there is some evidence indicating the dependence of exoskeletal calcification on environmental calcium levels in other crustacean species. In the blue crab and Atlantic shore crab (both marine species), post-molt calcium uptake from the ambient water is affected by calcium levels [15,16]. In the noble crayfish, Astacus astacus and the amphipod Gammarus lacustris (both freshwater species), a low-calcium environment decreases whole-body calcium content [17].…”