Host Imprinting in Anemonefishes (Pisces: Pomacentridae): Does it Dictate Spawning site Preferences?

Abstract

The olfactory cues, to which some species of anemonefish embryos imprint, are secreted in the mucus on the tentacles and the oral disc of the host anemone. Close contact of the eggs of anemonefishes with the host's tentacles seems therefore important to imprinting. A corollary of this observation is that if local environmental conditions sweep tentacles in one specific direction, then the eggs will be placed leeward of the tentacles, rather than to foremost way from the tentacles. Other known factors such as egg predation can also cause a spawning site preference. No study has examined the possibility of the existence of such a preference. In this study, we addressed two questions: (1) Does spawning site preference exist in anemonefishes? (2) If yes, is it possible to relate this to the imprinting hypothesis, i.e. does local ocean currents over the host anemone have any influence on this preference? Two different coral reef areas were surveyed for anemonefish groups with eggs present: Eilat and Na'ama in the Aquaba-bight, the Red Sea (RS), and areas at Lizard Island, the northern Great Barrier Reef (GBR). We found the anemonefishes Amphiprion akindynos (GBR), A. bicinctus (RS), A. melanopus (GBR), and A. perideraion (GBR), to have a distinctive spawning site preference. We discuss the relevance of these findings to anemonefish host imprinting.