Abstract
We discuss a macroscopical growth model which can be used to simulate growth forms of complex-shaped branching organisms with radiate accretive growth. This type of growth processes can be found in many different marine sessile organisms. We use scleractinian corals as an example. Using our simulation model we show how environmental factors such as nutrient distribution light availability, hydrodynamics influence growth patterns of coral colonies. To compare the simulated coral growth forms with those of real coral colonies, we quantitatively compared our modeling results with coral colonies of the morphologically variable Caribbean coral genus Madracis. Madracis species encompass a relatively large morphological variation in colony morphology and hence represents a suitable genus to compare simulated and real coral growth forms in 3D using a quantitative approach. This quantitative analysis of three-dimensional growth forms is based on a number of morphometric parameters such as branch thickness, branch spacing etc. Our results show that simulated coral morphologies share several morphological features with real coral colonies. We have measured morphological features of three closely related Caribbean coral species of the genus Madracis (M. formosa, M. decactis and M. carmabi). Morphological differences were then compared with phylogenies of the same species based on two nuclear DNA markers, i.e. ATPSa and SRP54. Our analysis showed that phylogenetic trees based on (macroscopical) morphological properties and phylogenetic trees based on DNA markers ATPSa and SRP54 are partially similar Our present model is able to partly capture the morphological variation in closely related and morphologically variable coral species of the genus Madracis.
Dr Jaap A. Kaandorp
Computational Science Lab, Faculty of Science, University of Amsterdam
Science Park 904, 1098 XH Amsterdam, The Netherlands