Differential responses of coral larvae to the colour of ambient light guide them to suitable settlement microhabitat.

R Soc Open Sci

Department of Integrative Biology , The University of Texas at Austin , 1 University Station C0930, Austin, TX 78712, USA.

Published: October 2015

Reef-building corals produce planktonic planula larvae that must select an appropriate habitat to settle and spend the rest of their life, a behaviour that plays a critical role in survival. Here, we report that larvae obtained from a deep-water population of Pseudodiploria strigosa settled more readily under blue light and in the dark, which aligns well with the light field characteristics of their natal habitat. By contrast, larvae of the shallow-water coral Acropora millepora settled in high proportions under blue and green light while settlement was less in the dark. Acropora millepora larvae also showed reduced settlement under red light, which should be abundant at shallow depth. Hypothesizing that this might be a mechanism preventing the larvae from settling on the exposed upwards-facing surfaces, we quantified A. millepora settlement in manipulated light chambers in situ on the reef. While A. millepora larvae naturally preferred settling on vertical rather than exposed horizontal surfaces, swapping the colours of upwards-facing and sideways-facing light fields was sufficient to invert this preference. We also tested if the variation in intrinsic red fluorescence in A. millepora larvae correlates with settlement rates, as has been suggested previously. We observed this correlation only in the absence of light, indicating that larval red fluorescent protein is probably not directly involved in light sensing. Our study reveals previously under-appreciated light-sensory capabilities in coral larvae, which could be an important axis of ecological differentiation between coral species and/or populations.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632519PMC
http://dx.doi.org/10.1098/rsos.150358DOI Listing

Publication Analysis

Top Keywords

millepora larvae
12
larvae
9
light
9
coral larvae
8
acropora millepora
8
settlement
5
millepora
5
differential responses
4
coral
4
responses coral
4

Similar Publications

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!