Localization and Quantification of Carbonic Anhydrase Activity in the Symbiotic ScyphozoanCassiopea xamachana

Abstract

The relationship between density and location of zooxanthellae and levels of carbonic anhydrase (CA) activity was examined in Cassiopea xamachana. In freshly collected symbiotic animals, high densities of zooxanthellae corresponded with high levels of CA activity in host bell and oral arm tissues. Bleaching resulted in a significant loss of zooxanthellae and CA activity. Recolonization resulted in full restoration of zooxanthellar densities but only partial restoration of CA activity. High levels of CA activity were also seen in structures with inherently higher zooxanthellar densities, such as oral arm tissues. Similarly, the oral epidermal layer of bell tissue had significantly higher zooxanthellar densities and levels of CA activity than did aboral bell tissues. Fluorescent labeling, using 5-dimethylaminonapthalene-1-sulfonamide (DNSA) also reflected this tight-knit relationship between the presence and density of zooxanthellae, as DNSA-CA fluorescence intensity was greatest in host oral epithelial cells directly overlying zooxanthellae. However, the presence and density of zooxanthellae did not always correspond with enzyme activity levels. A transect of bell tissue from the margin to the manubrium revealed a gradient of CA activity, with the highest values at the bell margin and the lowest at the manubrium, despite an even distribution of zooxanthellae. Thus, abiotic factors may also influence the distribution of CA and the levels of CA activity.

Metal bioaccumulation pattern by Cotylorhiza tuberculata (Cnidaria, Scyphozoa) in the Mar Menor coastal lagoon (SE Spain)

“…Depledge and Rainbow 1990). On the other hand, the capacity of the dinoflagellate to migrate between the tissues within amoebocytes (Estes et al 2003) may allow the migration of elements between the tissues as well.…”

Trace element accumulation in Cassiopea sp. (Scyphozoa) from urban marine environments in Australia

“…The ability of the zooxanthellae to migrate between the tissues within amoebocytes (Estes et al, 2003) may allow ready migration of elements between the tissues as well. In addition, it is possible that there may be deliberate absorption of some elements as a detoxification mechanism (Wang and Rainbow, 2005).…”

“…Different tissue functions and densities of zooxanthellae will certainly contribute to the variation (Estes et al, 2003). The variation in uptake and half-life efficiencies in A. aurita and C. andromeda (Fowler et al, 2004) suggest that zooxanthellae may explain differences in accumulation and sequestration of trace elements.…”

“…They possess an endosymbiotic relationship with Symbodium sp. and thus are capable of photosynthesis, which is associated with demonstrated efficiencies in uptake of inorganic nutrients and elements from the surrounding water column (Estes et al, 2003;Fowler et al, 2004).…”

The free-living Symbiodinium reservoir and scleractinian coral symbiont acquisition

“…Symbiodinium can also reach high densities in other hosts, including sea anemones (Venn et al 2008) and jellyfish (Estes et al 2003), reaching up to 6 × 10 6 cells mg (Stimson et al 2002). Although expelled cells are competent and photosynthetically active (Ralph et al 2001;Ralph et al 2005;Hill and Ralph 2007), the definitive survival of these cells in situ is unknown.…”