Conspicuous endolithic algal associations in a mesophotic reef-building coral
Understanding how corals and their symbionts specialize across depth gradients allows us to understand biodiversity in shallow and mesophotic coral ecosystems. Here we determined the prevalence of endolithic algal in Agaricia undata (17–83 m) and examined community changes within (shallow, upper and lower zones) and among sites (oceanic vs. continental siliciclastic influence). We observed exposed filaments of endolithic algae in some colonies, which in some cases surfaced the coral as tubular pipelines bridging A. undata costae. We also found multiple cryptic species within the monophyletic group of Ostreobium-like algae (12 rbcL types). Rarely explored as symbionts, Ostreobium in A. undata highlights its potential role in facilitating a broader depth range.
KeywordsMesophotic coral ecosystems Endolithic algae Symbiont Ostreobium spp.
This study was supported by COLCIENCIAS Grant No. 120465944147, Universidad de los Andes (Vicerrectoria de Investigaciones-Programa de Investigación en Especiación Ecológica) and CORALINA (Convenios 13-2014 and 21-2015). We thank N. Bolaños, E. Castro, J. Andrade, F. García, O. Ruiz, D. Seguro, L. Dueñas, M. Forero, L. Gutierrez, M. Gómez, M. Marrugo, P. Bongaerts, C. Ramirez and A. Henao.
Compliance with ethical standards
Conflict of interest
The authors declare they have no conflicts of interest.
- Ellis J, Solander DC (1786) The natural history of many curious and uncommon zoophytes: collected from various parts of the globe. B. White and Peter ElmslyGoogle Scholar
- Pyle RL (1998) Use of advanced mixed-gas diving technology to explore the coral reef “twilight zone”. In: Ocean pulse, pp 71–88Google Scholar
- Ralph PJ, Larkum AWD, Kühl M (2007) Photobiology of endolithic microorganisms in living coral skeletons: 1. Pigmentation, spectral reflectance and variable chlorophyll fluorescence analysis of endoliths in the massive corals Cyphastrea serailia, Porites lutea and Goniastrea australensis. Mar Biol 152:395–404CrossRefGoogle Scholar
- Slattery M, Lesser MP (2012) Mesophotic coral reefs: a global model of community structure and function. In: Proceedings of 12th international coral reef symposium cairns, pp 9–13Google Scholar
- Tribollet A (2008) The boring microflora in modern coral reef ecosystems: a review of its roles. Current developments in bioerosion. Springer, Berlin, Heidelberg, pp 67–94Google Scholar