In addition, if zooxanthellae do contribute substantially to the C budget of the host sponge, we hypothesize that this contribution is also influenced by the habitat in which the sponge lives, as the reduced light levels and the reduced zooxanthella
concentrations (Hill, 1999) of deeper locations force the host sponges to rely more heavily on heterotrophy.
For the analysis of temporal variation, each sample was homogenized in zooxanthella
isolation buffer (ZIB) (Rowan and Powers, 1991) and an aliquot taken for protein quantification using the micro-assay of the Bio-Rad Protein Assay (Bio-Rad Laboratories, Hemel Hempstead.
Since zooxanthellae are larger and therefore contain 3 (summer) and 2 (winter) times the carbon content of zoochlorellae (Table 1), a dividing zooxanthella
requires more carbon for growth.
Interspecific comparisons are important because corals may react differently to a change in their environmental conditions resulting from different levels of oxidative stress (Lesser, 1996), zooxanthella
genotypes (Rowan et al., 1997), pigments (Hoegh-Guldberg and Jones, 1999), tissue thickness (Loya et al., 2001), and colony shape (Glynn, 1993).
Percent infection was determined by taking a subsample of 100 larvae from each bowl and examining the larvae with light microscopy to quantify the proportion containing at least one zooxanthella
. Three subsamples were counted from each bowl of larvae.
mirabilis algal NOS activity were seen to be associated with bleaching corals (i.e., when zooxanthella
densities are below approximately 2 X [10.sup.6] cells/[cm.sup.2]; Fig.
The blastomeres were now 20-30 /[mu]m in diameter, even in size, and rarely contained more than one zooxanthella
Members of the species are densely populated with the zooxanthella
, Symbiodinium sp., and they have a large bell that allows repeated sampling of individuals over time.
Moreover, zoochlorellae translocate, to the host, photosynthetic products that differ qualitatively from zooxanthella
photosynthate (Minnick and McCloskey, cited by Verde and McCloskey, 1996), and zooxanthellae contribute more reduced carbon to the host's nutrition than do zoochlorellae (Verde and McCloskey, 1996).
Effect of different strains of the zooxanthella
Symbiodinium microadriaticum on growth and survival of their coelenterate and molluscan hosts.
franksi and its two sibling species; the only other zooxanthella
observed was Symbiodinium C.
Microbial invasion of the Caribbean by an IndoPacific coral zooxanthella