Skeletal growth of four scleractinian corals is not enhanced by in situ mesozooplankton enrichment

Cold-water corals (CWC) can be found throughout a wide range of latitudes (79°N–78°S). Since they lack the photosymbiosis known for most of their tropical counterparts, they may thrive below the euphotic zone. Consequently, their growth predominantly depends on the prevalent environmental conditions, such as general food availability, seawater chemistry, currents, and temperature. Most CWC communities live in regions that will face CaCO3 undersaturation by the end of the century and are thus predicted to be threatened by ocean acidification (OA). This scenario is especially true for species inhabiting the Chilean fjord system, where present-day carbonate water chemistry already reaches values predicted for the end of the century. To understand the effect of the prevailing environmental conditions on the biomineralization of the CWC Tethocyathus endesa, a solitary scleractinian widely distributed in the Chilean Comau Fjord, a 12-month in situ experiment was conducted. The in situ skeletal growth of the test corals was assessed at two sites using the buoyant weight method. Sites were chosen to cover the naturally present carbonate chemistry gradient, with pH levels ranging between 7.90 ± 0.01 (mean ± SD) and 7.70 ± 0.02, and an aragonite saturation (Ωarag) between 1.47 ± 0.03 and 0.98 ± 0.05. The findings of this study provide one of the first in situ growth assessments of a solitary CWC species, with a skeletal mass increase of 46 ± 28 mg per year and individual, at a rate of 0.03 ± 0.02% day. They also indicate that, although the local seawater chemistry can be assumed to be unfavorable for calcification, growth rates of T. endesa are comparable to other cold-water scleractinians in less corrosive waters (e.g., Lophelia pertusa in the Mediterranean Sea).

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Biotic Control of Skeletal Growth by Scleractinian Corals in Aragonite–Calcite Seas

PLoS ONE ◽

10.1371/journal.pone.0091021 ◽

2014 ◽

Vol 9 (3) ◽

pp. e91021 ◽

Cited By ~ 13

Author(s):

Tomihiko Higuchi ◽

Hiroyuki Fujimura ◽

Ikuko Yuyama ◽

Saki Harii ◽

Sylvain Agostini ◽

...

Keyword(s):

Scleractinian Corals ◽

Skeletal Growth ◽

Biotic Control

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Variable PSII functioning and bleaching conditions of tropical scleractinian corals pre-and post-bleaching event

Ocean Life ◽

10.13057/oceanlife/o020101 ◽

2018 ◽

Vol 2 (1) ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

SUSHMA MATTAN-MOORGAWA ◽

SOONIL DDV RUGHOOPUTH ◽

RANJEET BHAGOOLI

Keyword(s):

Fluorescence Yield ◽

Scleractinian Corals ◽

Bleaching Event ◽

Pocillopora Damicornis ◽

Pam Fluorometer ◽

Physico Chemical ◽

Chlorophyll Fluorescence Yield ◽

Solitary Coral ◽

Coral Health

Mattan-Moorgawa S, Rughooputh SDDV, Bhagooli R. 2017. Variable PSII functioning and bleaching conditions of tropical scleractinian corals pre-and post-bleaching event. Ocean Life 1: 1-10. This study compared pre-bleaching and post-bleaching conditions of eight reef-building corals, Acropora cytherea, Acropora hyacynthus, Acropora muricata, Acropora sp., Pocillopora damicornis, Pocillopora eydouxi, Galaxea fascicularis and Fungia sp., in terms of visual coloration (non-bleached (NB), pale (P), partially bleached (PB) and bleached (B)) and chlorophyll fluorescence yield at photosystem II (PSII)). A total of twenty colonies from twelve stations along four transects were surveyed at Belle-Mare, Mauritius, from October 2008 to October 2009, and compared to the CoralWatch Coral Health Chart. PSII functioning, measured as Fv/Fm, were recorded in coral samples using a pulse-amplitudemodulated (PAM) fluorometer. Physico-chemical parameters (sea surface temperature, dissolved oxygen, salinity and pH) were recorded in situ. An increase in SST up to 31.4ºC in February 2009 triggered the bleaching event observed in May 2009 at the site. Acroporids showed the first sign of bleaching and paling as from January 2009 when mean SST was at 30ºC. Branching coral (P. eydouxi) and solitary coral (Fungia sp.) exhibited only 15% of their colonies showing paling by April 2009. A. cytherea, A. hyacynthus, and A. muricata showed varying bleaching conditions [Pale (P), Partially-bleached (PB) and Bleached (B)] at onset of the bleaching event whilst Acropora sp. showed only a paling of its colonies. Post-bleaching data indicated a differential recovery in visual coloration and PSII functioning among the corals. P. eydouxi and Fungia sp. showed no bleaching conditions throughout the study. P. damicornis and G. fascicularis indicated a quick coloration recovery from P to NB after the bleaching event, although their maximum quantum yield at PSII did not show significant changes in P and NB samples. A. muricata recovered faster than A. hyacynthus and A. cytherea in terms of PSII functioning. A differential recovery was observed post-bleaching event among the eight coral species, in terms of recovery of color and PSII functioning. The order of recovery was as follows: massive-like/ solitary corals > branching and semi-bulbous corals > tabular corals.

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The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽

10.1017/s0094837300025707 ◽

1980 ◽

Vol 6 (02) ◽

pp. 146-160 ◽

Cited By ~ 29

Author(s):

William A. Oliver

Keyword(s):

Critical Points ◽

Scleractinian Corals ◽

Convincing Evidence ◽

Early Triassic ◽

Rugose Corals ◽

History Of ◽

The Subject ◽

Relationship Of ◽

The Relationship ◽

Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

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