Biomass of Living Tissues
299
colonies are perpendicular to the direction of the dominating current. Their
ends effectively ward off the action of the current upon the colony. Thus
they oppose well hydraulic stress (Grigg 1972). At the same time, such a
position of the fans is optimal for catching food particles passing by with the
current (Leversee 1976). No wonder that this form and orientation of
colonies are peculiar to most ahermatypic gorgonians feeding on plankton
(Muzik and Wainwright 1977).
8.2 Biomass of Living Tissues
During studies of the functional activity of corals the parameters obtained
have most often been expressed per unit of surface of their colonies or per
dry or wet weight (d. Sects. 9.1, 9.2). But the bulk of their mass in
scleractinians (-98%) as well as in zoantharians and in octocorals (up to
90%) comprises inert organic and inorganic structural materials: skeletal
aragonite, chi tine-like organic material of coenosarc and of axial filaments,
wax-like protecting substances. This raises the problem how to estimate the
biomass of functionally active tissues of corals, the biomass of their polyps
and zooxanthellae. Some researchers have accepted as the biomass of tissues
the total organic matter content in the colony (excluding the axial chord of
octocorals). The content of organic matter was estimated in the decalcinated
material of colonies (Davies 1980), or in their alkaline hydrolisates (Sorokin
1984b). Muscatine and Cernichiari (1969) evaluated the biomass of polyps
measuring the content of protein in corals. But in their estimates coenosarc
was also included into the biomass of polyps. It was necessary to find a way
to isolate single polyps from the coenosarc. This problem was finally solved.
Polyps were cut out one by one - with the aid of binoculars - from the
decalcinated coenosarc of the coral colony, previously kept for a week in
10% formalin solution (Sorokin 1984b).
Various methods were used to measure the biomass of zooxanthelleae.
Most often their total number is counted per 1 polyp or per 1 cm 2 of coral
surface, and the average volume of their cells has been measured.
Zooxanthellae have a spheroid form of 9-12 ~ diameter and 400-600 ~3
average volume. To count them, pieces of corals with a definite number of
polyps, which had been prepared in same way as mentioned above were
crushed in a mortar. Then the carbonate sediment was dissolved with the aid
of HC!. The neutralized suspension was filtered on a membrane filter, which
was then stained with erythrosine and examined under the microscope after
clearing it with immersion oil (Sorokin 1984b). To isolate the zooxanthellae,
some other methods were employed, including mechanical scraping of living
tissues, washing them out with the aid of "Water-Pik" apparatus (Johannes
and Wiebe 1970), or homogenization of colonies (Lasker 1977). To separate
the zooxanthellae from the flurry of tissues, gradient liquids were used.
299
colonies are perpendicular to the direction of the dominating current. Their
ends effectively ward off the action of the current upon the colony. Thus
they oppose well hydraulic stress (Grigg 1972). At the same time, such a
position of the fans is optimal for catching food particles passing by with the
current (Leversee 1976). No wonder that this form and orientation of
colonies are peculiar to most ahermatypic gorgonians feeding on plankton
(Muzik and Wainwright 1977).
8.2 Biomass of Living Tissues
During studies of the functional activity of corals the parameters obtained
have most often been expressed per unit of surface of their colonies or per
dry or wet weight (d. Sects. 9.1, 9.2). But the bulk of their mass in
scleractinians (-98%) as well as in zoantharians and in octocorals (up to
90%) comprises inert organic and inorganic structural materials: skeletal
aragonite, chi tine-like organic material of coenosarc and of axial filaments,
wax-like protecting substances. This raises the problem how to estimate the
biomass of functionally active tissues of corals, the biomass of their polyps
and zooxanthellae. Some researchers have accepted as the biomass of tissues
the total organic matter content in the colony (excluding the axial chord of
octocorals). The content of organic matter was estimated in the decalcinated
material of colonies (Davies 1980), or in their alkaline hydrolisates (Sorokin
1984b). Muscatine and Cernichiari (1969) evaluated the biomass of polyps
measuring the content of protein in corals. But in their estimates coenosarc
was also included into the biomass of polyps. It was necessary to find a way
to isolate single polyps from the coenosarc. This problem was finally solved.
Polyps were cut out one by one - with the aid of binoculars - from the
decalcinated coenosarc of the coral colony, previously kept for a week in
10% formalin solution (Sorokin 1984b).
Various methods were used to measure the biomass of zooxanthelleae.
Most often their total number is counted per 1 polyp or per 1 cm 2 of coral
surface, and the average volume of their cells has been measured.
Zooxanthellae have a spheroid form of 9-12 ~ diameter and 400-600 ~3
average volume. To count them, pieces of corals with a definite number of
polyps, which had been prepared in same way as mentioned above were
crushed in a mortar. Then the carbonate sediment was dissolved with the aid
of HC!. The neutralized suspension was filtered on a membrane filter, which
was then stained with erythrosine and examined under the microscope after
clearing it with immersion oil (Sorokin 1984b). To isolate the zooxanthellae,
some other methods were employed, including mechanical scraping of living
tissues, washing them out with the aid of "Water-Pik" apparatus (Johannes
and Wiebe 1970), or homogenization of colonies (Lasker 1977). To separate
the zooxanthellae from the flurry of tissues, gradient liquids were used.