Early Arrival Gives Reef Fish a Competitive Advantage

Researchers found that the timing of when young reef fish arrive at a coral reef substantially affects their chances of survival, with fish that arrive earlier gaining a competitive advantage over later arrivals through increased aggression and territory control. The researchers created experimental patch reefs in French Polynesia and experimentally controlled when young wrasse fish arrived, manipulating both the sequence (who came first) and timing (how much time separated arrivals) to measure survival and aggressive interactions. Both fish species survived best when they had no competitors, but when competitors were present, they did best arriving at the same time. Survival declined as each species entered progressively later than its competitor, with increased aggression from the earlier-arriving fish. The competitive advantage was about timing, not species identity; whichever species arrived first gained the advantage. Even within the same species, earlier arrivals had similar competitive advantages over later arrivals. The research shows that small differences in timing, just days or weeks, can determine which fish survive to adulthood on coral reefs. This has implications for understanding how coral reef communities assemble and how unpredictable ocean currents that deliver baby fish might affect reef diversity.

Citation

Geange, Shane W.; Stier, Adrian C. (2009). Order of arrival affects competition in two reef fishes. Ecology.

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