Larval settlement: the role of surface topography for sessile coral reef invertebrates

PLoS One. 2015 Feb 11;10(2):e0117675. doi: 10.1371/journal.pone.0117675. eCollection 2015.

Abstract

For sessile marine invertebrates with complex life cycles, habitat choice is directed by the larval phase. Defining which habitat-linked cues are implicated in sessile invertebrate larval settlement has largely concentrated on chemical cues which are thought to signal optimal habitat. There has been less effort establishing physical settlement cues, including the role of surface microtopography. This laboratory based study tested whether surface microtopography alone (without chemical cues) plays an important contributing role in the settlement of larvae of coral reef sessile invertebrates. We measured settlement to tiles, engineered with surface microtopography (holes) that closely matched the sizes (width) of larvae of a range of corals and sponges, in addition to surfaces with holes that were markedly larger than larvae. Larvae from two species of scleractinian corals (Acropora millepora and Ctenactis crassa) and three species of coral reef sponges (Luffariella variabilis, Carteriospongia foliascens and Ircinia sp.,) were used in experiments. L. variabilis, A. millepora and C. crassa showed markedly higher settlement to surface microtopography that closely matched their larval width. C. foliascens and Ircinia sp., showed no specificity to surface microtopography, settling just as often to microtopography as to flat surfaces. The findings of this study question the sole reliance on chemical based larval settlement cues, previously established for some coral and sponge species, and demonstrate that specific physical cues (surface complexity) can also play an important role in larval settlement of coral reef sessile invertebrates.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Behavior, Animal
  • Body Size
  • Coral Reefs*
  • Invertebrates / anatomy & histology*
  • Invertebrates / physiology
  • Larva / anatomy & histology
  • Larva / physiology
  • Movement
  • Surface Properties

Grants and funding

This work was undertaken with funding to SW through the Great Barrier Reef Foundation and under permit G13/36138.1, issued by the Great Barrier Reef Marine Park Authority. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.