| 'HARD' EVIDENCES FOR LARVAL AGGREGATION DURING THE PELAGIC STAGE: THE CASE OF THE CORAL-REEF FISH NEOPOMACENTRUS MIRYAE (POMACENTRIDAE) |
| Kiflawi, M., The Interuniversity Institute for Marine Sciences of Eilat, P.O.B. 469, Eilat, Israel 88103, and Ben-Gurion University, Be’er Sheva, Israel 84105, mkiflawi@bgu.ac.il; BEN-TZVI O., The Interuniversity Institute for Marine Sciences of Eilat, P.O.B. 469, Eilat, Israel 88103, and Tel-Aviv University, Tel-Aviv, Israel 69978, obentzvi@gmail.com ; Abelson A., Tel-Aviv University, Tel-Aviv, Israel 69978, avigdorA@tauex.tau.ac.il |
| Dispersal for most coastal marine fish species occurs during the pelagic larval period. The demography, ecology and evolutionary dynamics of the adult population is thus highly dependent on characteristics of recruiting cohorts; their source, size and composition. Direct tracking of larval trajectories is essentially impossible due to their diminutive size and the extent of the larval period. Fortunately, trace-elements incorporated in the otoliths of dispersing larvae can help fill the ensuing information gap. Here we present the first otolith-derived ('hard') evidence for the limited mixing of larvae originating from different sources, spread across the relatively small spatial extent of the norther Gulf of Aqaba, the Red Sea. Specifically, we show that recruiting cohorts of the Pomacentrid Neopomacentrus Miryae, which share the same hatching date and PLD, demonstrate considerable similarity in their chemical signatures; far greater than the similarity between cohorts. The similarity is found both in the core and along the extent of the otolith representing the pelagic duration; which corresponds to similarity in both origin and trajectory, respectively. The phenomenon was not repeated in a second Pomacentrid, Chromis viridis, recruiting to neighboring sites (albeit at a different time of year); suggesting species-specific effects. These findings are consistent with a growing realization that larval spatial distribution in the plankton is far more structured than previously believed; even at very small scales. |
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