The organic content of the proteinaceous portion of the skeleton of two Mediterranean gorgonian corals was estimated by means of two different methods: a gravimetric one (combustion and incineration) and by elemental analysis. Paramuricea clavata was investigated at a granitic shoal at the northern entrance to the Strait of Messina (Tyrrhenian Sea); Lophogorgia ceratophyta at a rocky station located off Tinetto Rock (Ligurian Sea). Both gorgonians were the visually dominant macrobenthic species in their habitat. Twenty colonies per species were collected in 1993, ages were estimated by counting axial annual growth increments, and the total content of the organic matrix of the skeleton was determined. The degree of axis mineralization was found to be different in the two species, suggesting different stiffening strategies to withstand water velocities. Annual weight increment of P. clavata due to skeletal organics was estimated in 12.72 g AFDW (ash free dry weight) m-2, while the total resident amount was 78.93 g AFDW m-2. L. ceratophyta yielded, respectively, 47.84 g AFDW m-2 yr-1 and 268.45 g AFDW m-2. Gorgonian corals can be thought of as ‘energy storer’ organisms, since only a minor part of the organic matter of the colony (i.e., coenenchymal tissue) is immediately available to consumers, while most of it is sequestered in the axial structures, and becomes available to decomposers only after the death of the colony. © 1996 Taylor & Francis Group, LLC.
Organic content in gorgonian axis: Structural function and implications for energy budget estimates
Mistri M.
1996
Abstract
The organic content of the proteinaceous portion of the skeleton of two Mediterranean gorgonian corals was estimated by means of two different methods: a gravimetric one (combustion and incineration) and by elemental analysis. Paramuricea clavata was investigated at a granitic shoal at the northern entrance to the Strait of Messina (Tyrrhenian Sea); Lophogorgia ceratophyta at a rocky station located off Tinetto Rock (Ligurian Sea). Both gorgonians were the visually dominant macrobenthic species in their habitat. Twenty colonies per species were collected in 1993, ages were estimated by counting axial annual growth increments, and the total content of the organic matrix of the skeleton was determined. The degree of axis mineralization was found to be different in the two species, suggesting different stiffening strategies to withstand water velocities. Annual weight increment of P. clavata due to skeletal organics was estimated in 12.72 g AFDW (ash free dry weight) m-2, while the total resident amount was 78.93 g AFDW m-2. L. ceratophyta yielded, respectively, 47.84 g AFDW m-2 yr-1 and 268.45 g AFDW m-2. Gorgonian corals can be thought of as ‘energy storer’ organisms, since only a minor part of the organic matter of the colony (i.e., coenenchymal tissue) is immediately available to consumers, while most of it is sequestered in the axial structures, and becomes available to decomposers only after the death of the colony. © 1996 Taylor & Francis Group, LLC.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
