Host recognition and possible imprinting in the anemonefish Amphiprion melanopus (Pisces:Pomacentridae)

Abstract

Many reef fish have strong microhabitat preferences when they settle to the juvenile population, and choices at h s time may influence fish survival. This is exemplified in anemonefishes (Family: Pomacentridae) that exhibit obligate symbiotic relationships with a restricted range of sea anemone species. This study examined how juvenile anemonefish Amphiprion rnelanopus select their host, and whether recognition and selection are me&ated by an imprinting-like mechanism. Specifically, we experimentally examined the host-selecbon made by A. rnelanopus that had been reared under constant conditions, but whose embryos had received 1 of 3 treatments: (l) in contact with a known natural host sea anemone, Entacmaea quadncolor; (2) in contact with the sea anemone Heteractis malu, which is not a host for A. melanopus m nature, but is a host for anemonefish of other species; and (3) without a sea anemone (or chemical cues released from sea anemones) at any life stage. Our study shows that olfaction, not vision, is used by juvenile A. melanopus to recognize host anemones. Furthermore, the choice of a settlement site for j u v e d e A. melanopusis strongly influenced by events that occur early in development, prior to the dispersal of larvae from their natal site. We suggest that juvenile A. melanopus possess an innate preference for E. quadricolor, a preference that is enhanced by imprinting. Interestingly, it was not possible to imprint A. melanopus larvae to the non-host sea anemone H. malu. which suggests that anemonefish host-imprinting may be rather restricted.

Can larval snapper, Pagrus auratus, smell their new home?

“…water type, ambient sound, presence of conspecifics) (Arvedlund and Nielsen 1996;Arvedlund et al 1999;Ross et al 2007;Simpson et al 2008). Olfaction has been shown to be an important settlement and orientation cue in settlement-stage coral reef fish larvae (Arvedlund and Nielsen 1996;Arvedlund et al 1999;Arvedlund and Takemura 2006;Dixson et al 2008;Huijbers et al 2008;Lecchini et al 2005a;Lecchini et al 2005b;MillerSims et al 2011). Similar to the results of this study, Huijbers et al (2008) showed that the French grunt (Haemulon flavolineatum), which has a similar life history to P. auratus, had a significant orientation preference for water taken from seagrass habitat over other choices.…”

“…Art = artificial seawater; Out = outside harbour; Harb ¼ harbour entrance; As ¼ Asian date mussel habitat; SG ¼ seagrass habitat; and ASG ¼ artificial seagrass water; n ¼ sample size; P ¼ probability of the data given the null hypothesis that there was no preference between the two water sources It has been often shown that settlement-stage fish select habitats according to their characteristics (e.g. water type, ambient sound, presence of conspecifics) (Arvedlund and Nielsen 1996;Arvedlund et al 1999;Ross et al 2007;Simpson et al 2008). Olfaction has been shown to be an important settlement and orientation cue in settlement-stage coral reef fish larvae (Arvedlund and Nielsen 1996;Arvedlund et al 1999;Arvedlund and Takemura 2006;Dixson et al 2008;Huijbers et al 2008;Lecchini et al 2005a;Lecchini et al 2005b;MillerSims et al 2011).…”

“…For example, both Gerlach et al (2007) and Dixson et al (2008) have shown that settlement-stage coral reef fish larvae are capable of discriminating between different reefs on the basis of water-borne chemical cues. Settling larvae have been shown to respond to a variety of olfactory signals, such as those from coral tissue and conspecifics (Lecchini et al 2005a(Lecchini et al , 2005b, or symbiotic partners (Elliott et al 1995;Arvedlund and Nielsen 1996;Arvedlund et al 1999). There is further evidence that settling larvae can discriminate between different reefs without any prior experience (Elliott et al 1995;Arvedlund and Takemura 2006;Dixson et al 2008), although early larval experiences may also influence habitat selection choices at settlement stage (Arvedlund and Nielsen 1996;Miller-Sims et al 2011).…”

Orientation from open water to settlement habitats by coral reef fish: behavioral flexibility in the use of multiple reliable cues

“…It is likely that for aquatic vertebrates, sound cues prevail over olfactory and visual cues when long distances are involved (Leis et al 1996), primarily because sound travels long distances through water , Montgomery et al 2006. Most research on orientation mechanisms in marine vertebrates, such as fishes, have focused on single sensory modalities (Basil et al 2000, Gerlach et al 2007, Huijbers et al 2008 or multiple modalities using non-conflicting cues (Arvedlund et al 1999, Brolund et al 2003, Hale et al 2009). However, little is known about the role of multimodality when it concerns conflicting cues.…”

Ocean acidification alters fish–jellyfish symbiosis

“…A wellknown marine symbiosis is that between anemones and clown-fishes (e.g. [7]), popularized through the animated movie Finding Nemo. However, fishes also form symbiotic relationships with other taxa such as jellyfish, the pelagic relatives of anemones.…”