As it is unlikely that successful settlement is solely a matter of chance (i.e. to find a suitable habitat), one of the greatest challenges facing the fish larvae is how to locate the relatively rare patches of coral reef habitat on which they settle and ultimately reside as adults. The answer must lie partly in the sensory modalities of fishes at settlement. Habitat selection is only possible if fish larvae could detect some environmental cues to select a suitable reef habitat at settlement. The present review aims at providing the latest works dealing with information perception in coral reef fish larvae at settlement. Two decades ago, it was generally assumed that larval behaviors and sensory abilities at settlement were considered too feeble to significantly affect dispersal outcomes. Several recent studies showed that recognition of suitable reef habitats by fish larvae at settlement is based on a combination of visual, chemical and acoustic cues. The first part of our review shows the main advances in the knowledge of visual, chemical and acoustic cues used by fish larvae to detect an island, a reef, a micro-habitat, a conspecific or some predators. The second part of our review deals with the effect of imprinting and/or innate capabilities. The third part focuses on the different cues used at different scales and underlines some contradictory results about the distance of transmission and detection of chemical and acoustic cues in coral reefs. Finally, as global and regional environmental changes have stressed coral reefs to such an extent that they are either destroyed or in decline, the fourth part presents the effects of both anthropogenic and environmental stressors on information perception and response capacities in coral reef fish larvae. If polluted seawater disrupts the larval abilities to find a suitable reef habitat, fish larvae may spend more time in the planktonic environment, resulting in increased energetic costs and prédation risk, and consequently a lower larval settlement. We hypothesise that as the stability offish communities is dependent, in part, on the stability of social interactions, the disruption of "larvae-habitat relationships" can have major consequences for larval settlement into adult population with further repercussions for the ecosystem as a whole. Overall, larval settlement of coral reef fish is an excellent example of the complexity of interactions between an organism and its environment as without perceiving environmental cues, fish larva would have very little chance of selecting a suitable reef habitat. Moreover, understanding the relationship between reef state and settlement potential will allow management planning for the maintenance of coral reefs that are increasingly degraded.
|Number of pages||10|
|Journal||Vie et Milieu|
|State||Published - 1 Jun 2015|
ASJC Scopus subject areas
- Aquatic Science