title: Effects of delayed settlement on post-settlement growth and survival of scleractinian coral larvae.
abstract: Demographic connectivity requires both the dispersal of individuals between sub-populations, and their subsequent contribution to population dynamics. For planktonic, non-feeding marine larvae, the capacity to delay settlement enables greater dispersal distances, but the energetic cost of delayed settlement has been shown to adversely impact post-settlement fitness in several taxa. Here, we assess whether delayed settlement influences mortality rates or growth rates for the first 6 weeks following settlement of the scleractinian coral, Acropora tenuis. Coral larvae that were settled at 2, 4, and 6 weeks after spawning, and then deployed in the field, showed negligible effects of delayed settlement on post-settlement survival and time to initial budding for colony formation. Between-cohort differences in budding rate appeared to be explained by temporal variation in the post-settlement acquisition of zooxanthellae. The potential for coral larvae to remain in the pelagic zone for increased periods of time with little to no effect on post-settlement survival and growth suggests that the capacity for delayed settlement is likely to have meaningful demographic consequences for broadcast-spawning reef-building corals, and that the predicted trade-off between delayed settlement and post-settlement fitness is less applicable to reef-building scleractinian corals than other taxa with non-feeding larvae.
authors.affiliation: School of Marine and Tropical Biology, James Cook University, Townsville, QLD, 4811, Australia, erin.graham@my.jcu.edu.au.
authors.forename: Erin M
authors.initials: EM
authors.lastname: Graham
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Baird
authors.forename: Bette L
authors.initials: BL
authors.lastname: Willis
authors.forename: Sean R
authors.initials: SR
authors.lastname: Connolly
mesh_terms: D000818:Animals; D037421:Anthozoa / Q000254:growth & development / Q000502:physiology*; D057894:Coral Reefs; D007814:Larva / Q000254:growth & development / Q000502:physiology; D008136:Longevity; D011157:Population Dynamics; D011793:Queensland