Effects of depth and eutrophication on the zooxanthella clades of Stylophora pistillata from the Gulf of Eilat (Red Sea)

Abstract

ABSTRACT1. The symbiotic association between corals and zooxanthellae has been a major contributing factor in the success of reef-building corals.2. The diversity of zooxanthellae harboured in the hermatypic coral Stylophora pistillata in the Gulf of Eilat (Aqaba), northern Red Sea, was investigated on the basis of the length and sequence variation of the 18S small subunit ribosomal DNA. Of several clades found worldwide, only clades A and C were found to be associated with this coral species in the Gulf.3. No correlation between the pink and brown colour morphs of the coral S. pistillata and the zooxanthella clade was found. Shallow-water colonies (5 m) harbour clade A while deeper-water colonies (17 m) harbour either clade A or C. This coral is a brooding species that associates with different zooxanthellae at different depths.4. Eutrophication from fish farms did not affect clade identity associated with Stylophora.

Nutritional status and metabolism of the coral Stylophora subseriata along a eutrophication gradient in Spermonde Archipelago (Indonesia)

“…Another explanation for the different zooxanthellae characteristics may be found in adaptive processes, such as a change in zooxanthellae genotypes from mid-shelf to near-shore. Although this could not be found for the congener S. pistillata (van Oppen et al 2005;Lampert-Karako et al 2008), other coral species, e.g., of the genus Acropora, changed their genotypes with distance from shore (van Oppen et al 2005). Overall, these possible mechanisms reveal a high acclimatization potential of the coral to nutrient enrichment and turbidity, which lead to the increasing P g with proximity to shore.…”

Ammonia flux, physiological parameters, and Symbiodinium diversity in the anemonefish symbiosis on Red Sea coral reefs

“…This change, however, does not appear to affect the ecology of the holobiont, as the proportion of anemones with each pattern did not vary significantly with depth, irradiance, or number of fish symbionts, and the physiological parameters of these anemones did not vary between the C1 18S-rDNA variants. In contrast, Symbiodinium types vary with depth in some stony corals (Lampert-Karako et al 2008) and corallimorpharians (Kuguru et al 2008) on Red Sea coral reefs. The novel Symbiodinium Clade C 18S-rDNA RFLP profile detected here has not been reported previously from other symbiotic cnidarians at the same reef sites (Barneah et al 2004;Lampert-Karako et al 2008;Kuguru et al 2008).…”

“…In contrast, Symbiodinium types vary with depth in some stony corals (Lampert-Karako et al 2008) and corallimorpharians (Kuguru et al 2008) on Red Sea coral reefs. The novel Symbiodinium Clade C 18S-rDNA RFLP profile detected here has not been reported previously from other symbiotic cnidarians at the same reef sites (Barneah et al 2004;Lampert-Karako et al 2008;Kuguru et al 2008).…”

“…In contrast, many stony corals vary their chlorophyll concentrations per microalgal cell with depth or irradiance levels (reviewed in Stambler et al 2008), a pattern that does not occur in some anemones and corals (Titlyanov et al 1980;Kuguru et al 2008). Unlike most sessile reef cnidarians for which exposure to light correlates directly with depth (Falkowski et al 1990;Lampert-Karako et al 2008), the light intensity experienced by mobile sea anemones may depend primarily on their active microhabitat selection during the benthic phase (Muller-Parker and Davy 2001), in which they often attach their pedal disks in reef holes (Fautin and Allen 1997;Porat and Chadwick-Furman 2005). This ability to select reef microhabitats likely underlies the significant correlation of Symbiodinium abundance with light intensity, but not with depth.…”

“…As such, anemonefishes indirectly provide shelter benefits to the dinoflagellates by enhancing the growth and survival of their anemone hosts (Porat and Chadwick-Furman 2005;Holbrook and Schmitt 2004; dinium can vary substantially among phylogenetic types; for example, some Symbiodinium lineages tend to occur at higher irradiance and to resist bleaching at elevated temperatures better than other phylogenetic types (Warner et al 1999;Baker 2003;Rowan 2004;Tchernov et al 2004;Reynolds et al 2008). For some cnidarian species, associations with particular Symbiodinium types correlate with the geographic distribution, depth, temperature, and/or microhabitat of the host (Toller et al 2001;Ulstrup and van Oppen 2003;LaJeunesse et al 2003;Fabricius et al 2004;Thornhill et al 2006a;Kuguru et al 2007;Lampert-Karako et al 2008). Thus, for at least some host cnidarians, environmental niche partitioning may select for Symbiodinium types that convey advantages under the conditions available in certain microhabitats (see also Buddemeier and Fautin 1993;Baker 2003;Berkelmans and van Oppen 2006).…”