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

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.