[Coral-List] Isis hippuris, Indonesia

Sonia Rowley srowley at hawaii.edu
Thu Jan 4 16:35:46 EST 2018

Dear All

Please find below the link to transplant work on *Isis hippuris* in
"Acclimatory capacity of the Gorgonian *Isis hippuris* Linnaeus, 1758 to
environmental change in SE Sulawesi, Indonesia"

Also here: https://www.sciencedirect.com/science/

Happy New Year!



Coral reefs within the Indonesian archipelago are some of the most
biodiverse yet anthropogenically compromised marine ecosystems. Within the
Wakatobi Marine National Park (WMNP), SE Sulawesi, Indonesia, pronounced
environmental clines are either caused or exacerbated by marine resource
subsistence and destruction. The protected zooxanthellate gorgonian (sea
fan coral) *Isis hippuris* Linnaeus, 1758 however, thrives on degraded
reefs, with distinct morphotypes across contrasting reef environments
within the region. To investigate if *I. hippuris* morphotypes are
environmentally induced (plastic) or genetically derived (fixed),
reciprocal transplant experiments (RTEs) were conducted across
environmental gradients of light attenuation and anthropogenic disturbance.
Phenotypic traits were measured and grouped into modules (colony, polyps,
sclerites, optical parameters) to assess the physiological responses and
endosymbiont specificity of each *I. hippuris* morphotype to environmental
change. Trait modules were then modelled for tests of integration to
determine phenotypic traits that interact to delimit *I. hippuris* morphotypes
in response to environmental perturbation. After one-year, survivorship was
lowest in clones transplanted from healthy to the degraded reef, suggesting
the onset of immigrant inviability. Multivariate analyses revealed that
phenotypic traits in healthy source colonies consistently showed
significant trait plasticity, whereas residents from the impacted site were
relatively insensitive to environmental change. Of the 38 phenotypic traits
assessed, 17 were identified as driving test dissimilarities, most notably
in branching dynamics, polyp density, capstan and spindle sclerite
dimensions, and *Symbiodinium* chlorophyll *a* light energy absorbance
efficiency (for photosynthesis). Specifically, photoacclimatory responses
were integrated at the morphological and bio-optical levels, with
chlorophyll *a* light harvesting efficiency maintained during reduced
pigment density resulting from an increase in host sclerite articulation
that maximized the internal light field in healthy clones on degraded
reefs. Variable optical responses were not attributed to endosymbiont type,
as all test colonies possessed a novel *Symbiodinium* Clade D1a. In
summary, patterns of phenotypic variability within the *I. hippuris* holobiont
likely represent incipient ecological divergence, with a high capacity for
plasticity that has become fixed through ongoing anthropogenic disturbance
on degraded reefs.

Sonia J. Rowley PhD
Postdoctoral Research Affiliate
University of Hawai'i at Manoa
POST 713, 1680 East-West Road
Honolulu, HI 96822
+1 808 348 6224

Research Affiliate - Bishop Museum
Chief Science Officer - Assoc. Marine Exploration

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