Effect of Nutrient Diffusion and Flow on Coral Morphology

Kaandorp, Jaap A.; Lowe, C. P.; Frenkel, Daan; Sloot, P.M.A.

doi:10.1103/physrevlett.77.2328

Cited by 103 publications

(70 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our study, flow determined both the colony symmetry and the morphological characteristics of the individual branches, corroborating the conclusion that exposure to flow was responsible for the striking morphological differences found in P. damicornis in reefs exposed to different levels of flow intensity (see Fig. 1.1 in Kaandorp & Kuebler 2001). A visual survey of different coral reefs in the Gulf of Aqaba (A. Genin unpubl.…”

Section: Discussionsupporting

confidence: 87%

“…Flow-induced enhancement of skeletal growth was observed in Pocillopora damicornis (Nakamura & Yamasaki 2005, Suzuki et al 2007 and Stylophora pistillata (Nakamura & Yamasaki 2005). Using unidirectional flow in models simulating mass fluxdependent growth in corals, Kaandorp et al (1996) showed a development of strong skeletal asymmetry, similar to that shown in a photograph of Acropora reticulate in Vogel (1981). A. cervicornis colonies that grew in an exposed reef developed more 'bushy' and denser branches than those growing in a protected lagoon (Bottjer 1980).…”

Section: Discussionmentioning

confidence: 90%

See 1 more Smart Citation

Environmental versus intrinsic determination of colony symmetry in the coral Pocillopora verrucosa

Mass¹,

Genin²

2008

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The morphology of corals is strongly dependent on environmental conditions. Different morphologies can be induced by flow and light due to their effects on respiration, production, calcification and prey capture. Yet, colonies of many branching corals exhibit a radial symmetry, possibly indicating an intrinsic determination of colony morphology. The scleractinian coral Pocillopora verrucosa (Ellis and Solander, 1786) is a common species in the Red Sea, displaying striking flow-dependent plasticity in colony morphology. Branches of this coral are thicker and more compact in habitats exposed to stronger flow, but the colonies are usually radially symmetric. The objective of this study was to experimentally examine whether the colony symmetry in this species is determined by intrinsic or extrinsic factors. Six corals were exposed in situ for 4 mo to a unidirectional flow generated with submerged pumps, creating asymmetric flow, stronger at the side facing the pump. The up-current side of the corals developed higher concentrations of chlorophyll and proteins, greater density of zooxanthellae, and displayed a more compact morphology and longer linear extension. While asymmetry in photosynthesis and photosynthates may disappear due to within-colony translocation, our findings on asymmetry in skeletal growth and morphology indicate that environmental conditions generate lasting asymmetry in corals. Current measurements indicate that the ubiquitous symmetry observed in P. verrucosa is apparently due to a corresponding symmetry in the flow.KEY WORDS: Flow · Zooxanthellae · Chlorophyll · Morphology · Red Sea Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 369: [131][132][133][134][135][136][137] 2008 mental conditions than another, and radial symmetry can develop if the governing factors around the coral are symmetric.The objective of this study was to experimentally examine the relative importance of intrinsic and extrinsic factors in determining the colony symmetry in Pocillopora verrucosa. MATERIALS AND METHODSA flow-manipulation experiment was carried out from 4 September 2006 to 16 January 2007 at 8 m depth in the coral reef off the H. Steinitz Marine Biology Laboratory, Eilat, Israel (Red Sea, 29°30' N, 34°56' E). This reef is part of a 5 km stretch of coastline containing reef interspersed with open sand regions devoid of corals. The reef is dominated by hermatypic corals. Soft corals, anemones, sponges, tunicates and polychaetes are also common (Fishelson 1971). The currents at the study site are predominantly oriented parallel to the shore line with an average near-bottom flow speed of ~5 cm s -1 (Genin & Paldor 1998). Semidiurnal reversals of flow direction occurred during May to October, whereas lower frequency reversals (period of several days) are dominant during winter (Monismith & Genin 2004).Our study focused on the scleractinian coral Pocillopora verrucosa (Ellis and Solander, 1786) a common species in a variety of reef environments of the Red S...

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Discussionmentioning

confidence: 90%

Environmental versus intrinsic determination of colony symmetry in the coral Pocillopora verrucosa

Mass¹,

Genin²

2008

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…Relatively recently within computational physics an alternative method for solving the hydrodynamic equations, the lattice Boltzmann method, has been developed. This method has been successfully applied in various case studies with complex-shaped boundary conditions in 3D problems (Heijs & Lowe 1995;Kaandorp et al 1996;Koponen et al 1998;Kandhai et al 2002). It has been demonstrated that this method is competitive with conventional methods (e.g.…”

Section: (B) Modelling the Flow Patternsmentioning

confidence: 99%

Simulation and analysis of flow patterns around the scleractinian coralMadracis mirabilis(Duchassaing and Michelotti)

Kaandorp

Koopman

Sloot

et al. 2003

Phil. Trans. R. Soc. Lond. B

Self Cite

View full text Add to dashboard Cite

Three-dimensional morphologies of Madracis mirabilis were obtained using X-ray computed tomography scanning techniques. The morphologies were used to simulate the flow patterns around the colony. In the simulations, the thin-branching low-flow morph with a relatively larger branch-spacing was compared with the more compact high-flow morph of M. mirabilis. For both morphologies, the inside-colony flow velocities were computed for Reynolds numbers ranging from 154 to 3840. In the high-flow morph, it was found that in the range of investigated Reynolds numbers a stagnant region develops within the colony, whereas in the low-flow morph the stagnant region disappeared. Experiments done under natural conditions suggest that a morph is adapted to a certain external flow velocity and develops a stagnant region below a particular threshold for the external flow velocity. When the external flow velocity exceeds a certain threshold, which is characteristic for the growth form, the core velocity becomes equal to the external velocity. A potential application of a profile of core velocities for a range of Reynolds numbers for a certain morph is the prediction of the optimal external flow velocity for a certain morph, and this can be used to assess the state of the physical (palaeo-) environment.

show abstract

“…Such conditions occur on a daily basis on reefs where flow is dominated by tidal cycles (20,21) and in sheltered areas within lagoons or on leeward parts of the reef (18,22,23). Furthermore, ambient flow is significantly reduced within densely branched corals, where parts of the colony experience over 90% reduction in fluid flow compared with conditions outside the colony (18,23,24).…”

mentioning

confidence: 99%

Vortical ciliary flows actively enhance mass transport in reef corals

Shapiro

Fernández

Garren

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

179

167

View full text Add to dashboard Cite

The exchange of nutrients and dissolved gasses between corals and their environment is a critical determinant of the growth of coral colonies and the productivity of coral reefs. To date, this exchange has been assumed to be limited by molecular diffusion through an unstirred boundary layer extending 1-2 mm from the coral surface, with corals relying solely on external flow to overcome this limitation. Here, we present direct microscopic evidence that, instead, corals can actively enhance mass transport through strong vortical flows driven by motile epidermal cilia covering their entire surface. Ciliary beating produces quasi-steady arrays of counterrotating vortices that vigorously stir a layer of water extending up to 2 mm from the coral surface. We show that, under low ambient flow velocities, these vortices, rather than molecular diffusion, control the exchange of nutrients and oxygen between the coral and its environment, enhancing mass transfer rates by up to 400%. This ability of corals to stir their boundary layer changes the way that we perceive the microenvironment of coral surfaces, revealing an active mechanism complementing the passive enhancement of transport by ambient flow. These findings extend our understanding of mass transport processes in reef corals and may shed new light on the evolutionary success of corals and coral reefs.coral microenvironment | coral reef evolution | diffusion boundary layer | microfluidics | biological fluid mechanics

show abstract

Effect of Nutrient Diffusion and Flow on Coral Morphology

Cited by 103 publications

References 10 publications

Environmental versus intrinsic determination of colony symmetry in the coral Pocillopora verrucosa

Environmental versus intrinsic determination of colony symmetry in the coral Pocillopora verrucosa

Simulation and analysis of flow patterns around the scleractinian coralMadracis mirabilis(Duchassaing and Michelotti)

Vortical ciliary flows actively enhance mass transport in reef corals

Contact Info

Product

Resources

About