title: The role of vision for navigation in the crown-of-thorns seastar, Acanthaster planci.
abstract: Coral reefs all over the Indo-Pacific suffer from substantial damage caused by the crown-of-thorns seastar Acanthaster planci, a voracious predator that moves on and between reefs to seek out its coral prey. Chemoreception is thought to guide A. planci. As vision was recently introduced as another sense involved in seastar navigation, we investigated the potential role of vision for navigation in A. planci. We estimated the spatial resolution and visual field of the compound eye using histological sections and morphometric measurements. Field experiments in a semi-controlled environment revealed that vision in A. planci aids in finding reef structures at a distance of at least 5 m, whereas chemoreception seems to be effective only at very short distances. Hence, vision outweighs chemoreception at intermediate distances. A. planci might use vision to navigate between reef structures and to locate coral prey, therefore improving foraging efficiency, especially when multidirectional currents and omnipresent chemical cues on the reef hamper chemoreception.
authors.affiliation: Department Animal Ecology I, University of Bayreuth and BayCEER, Universitaetsstr. 30, 95447 Bayreuth, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Sigl
authors.affiliation: Department Animal Ecology I, University of Bayreuth and BayCEER, Universitaetsstr. 30, 95447 Bayreuth, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Steibl
authors.affiliation: Department Animal Ecology I, University of Bayreuth and BayCEER, Universitaetsstr. 30, 95447 Bayreuth, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Laforsch
mesh_terms: D000818:Animals; D002628:Chemoreceptor Cells / Q000378:metabolism*; D057894:Coral Reefs; D011157:Population Dynamics; D065854:Spatial Navigation / Q000502:physiology*; D013215:Starfish / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*