%0 Journal Article
%T Macroscopic Modelling of Environmental Influence on Growth and Form of Sponges and Corals Using the Accretive Growth Model
%A Jaap A. Kaandorp
%J ISRN Biomathematics
%D 2013
%R 10.1155/2013/159170
%X 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 and a branching sponge as an example. With the radiate accretive growth model a wide range of morphologies and the influence of the physical environment (light and nutrient distribution by advection-diffusion) can be modelled. We show an (preliminary) example of how the accretive growth model can be coupled with a model of gene regulation and body plan formation in a branching sponge. 1. Introduction Many marine sessile organisms from very different taxonomical groups show a strong morphological plasticity, which is in many cases related to the impact of the physical environment. Two dominant parameters influencing morphological plasticity are water movement and the availability of light in photosynthetic organisms. Environmental parameters, closely linked to water movement, are the supply of suspended material in filter-feeding organisms and sedimentation. Sedimentation may also strongly influence the availability of light. Examples of studies in which the morphological plasticity and the relation to physical environment have been investigated are growth forms of the scleractinian Montastrea annularis and local light intensities [1, 2]; growth forms of the hydrozoan Millepora and the exposure to water movement [3, 4]; variations in morphology due to differences in exposure to water movement in the scleractinians Pocillopora [5, 6], Madracis [7, 8], and Agaricia agaricites [9]; colony forms of the bryozoan Electra pilosa and the influence of nutrient supply [10]; shape of coralline algae and the effect of exposure to water movement [11]; growth forms of the sponge Haliclona oculata [12, 13] and exposure to water movement. A detailed review on the morphological plasticity in corals and the influence of the environment can be found in a recent paper by Todd [14]. There are a large number of studies [14] where scleractinian coral colonies have been transplanted from one environment to a different one to identify the impact of the physical environment on the growth form of the colony. In [4] hydrozoan colonies (Millepora) and in [13] sponges (Haliclona oculata) were transplanted from sheltered to exposed environment and vice versa. There are a number of problematic issues in these experiments. The first issue is that many transplantation experiments were done with organisms or colonies which
%U http://www.hindawi.com/journals/isrn.biomathematics/2013/159170/