The Experts below are selected from a list of 228 Experts worldwide ranked by ideXlab platform

Christopher N Battershill - One of the best experts on this subject based on the ideXlab platform.

  • larval vertical migration and hierarchical selectivity of Settlement in a brooding marine sponge
    Marine Ecology Progress Series, 2008
    Co-Authors: Steve W Whalan, Piers Ettingerepstein, Christopher N Battershill
    Abstract:

    Knowledge of larval behaviours of sessile marine invertebrates from release to recruitment and of the role these behaviours play in determining adult distributions is limited. In manipulative experiments using larvae from the Great Barrier Reef sponge Rhopaloeides odorabile, we quantified larval behaviours associated with vertical migration, phototaxis and swimming ability. We also Measured Settlement responses to cues associated with light, Settlement surface micro-topography, coral rubble and biofilms. Following an afternoon release, the majority of larvae (72%) migrated vertically to the surface (light) for 6 to 18 h. After 24 h, 55% of active larvae had moved from the surface to the bottom and maintained this position for up to 54 h before settling. Larvae did not display gregarious Settlement patterns, or a preference for Settlement surface topographies, but did preferentially settle to light-exposed surfaces. Initial Settlement to biofilms or coral rubble was higher than in controls with no cue. However, the transition from initial Settlement and attachment to metamorphosis was much higher when treatments comprised a combination of biofilm and coral rubble compared to biofilm-only treatments (49 vs. 9%). Overall, this demonstrates that hierarchical cues contribute to selective Settlement. Vertical migration to surface waters facilitates passive dispersal via wind-driven surface currents and contributes to wide-scale dispersal, while a subsequent demersal phase, where larvae actively explore the benthos for Settlement sites, enables dispersal over fine, micro-geographic spatial scales.

De Nys Rocky - One of the best experts on this subject based on the ideXlab platform.

  • Larval Settlement: the role of surface topography for sessile coral reef invertebrates
    'Public Library of Science (PLoS)', 2015
    Co-Authors: Whalan Steve, Abdul Wahab, Muhammad A., Sprungala Susanne, Poole, Andrew J., De Nys Rocky
    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

  • Data from: Larval Settlement: the role of surface topography for sessile coral reef invertebrates
    2015
    Co-Authors: Whalan Steve, Abdul Wahab, Muhammad A., Sprungala Susanne, Poole, Andrew J., De Nys Rocky
    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

Chairat Teerawattanasuk - One of the best experts on this subject based on the ideXlab platform.

  • 2d and 3d numerical simulations of reinforced embankments on soft ground
    Geotextiles and Geomembranes, 2008
    Co-Authors: D T Bergado, Chairat Teerawattanasuk
    Abstract:

    Abstract Utilizing the same constitutive models and properties of foundation soils as published by previous researchers, two full-scale test embankments, namely steel grid embankment having longer plan dimensions with length-to-width ratio of 3.0 (long embankment) and hexagonal wire mesh reinforced embankment having shorter plan dimensions with length-to-width ratio of 1.0 (short embankment), were investigated using numerical simulation in two-dimensional (2D) and three-dimensional (3D) explicit finite-difference programs, FLAC2D and FLAC3D, respectively. The 2D numerical analysis simulated the overall behavior of the steel grid reinforced “long” embankment with very reasonable agreement between the field measurements and the calculated values. On the other hand, the 3D numerical analysis simulated the overall behavior of the hexagonal wire mesh reinforced “short” embankment. Furthermore, the simulation results from the FLAC3D used in the 2D analysis agreed with the Measured Settlement data in the “long” embankment as well as the 2D predictions from FLAC2D. The 2D and 3D numerical analyses should be considered important factors that may affect the numerical simulation results which are consistent with the current Settlement predictions with Skempton–Bjerrum corrections.

Steve W Whalan - One of the best experts on this subject based on the ideXlab platform.

  • larval vertical migration and hierarchical selectivity of Settlement in a brooding marine sponge
    Marine Ecology Progress Series, 2008
    Co-Authors: Steve W Whalan, Piers Ettingerepstein, Christopher N Battershill
    Abstract:

    Knowledge of larval behaviours of sessile marine invertebrates from release to recruitment and of the role these behaviours play in determining adult distributions is limited. In manipulative experiments using larvae from the Great Barrier Reef sponge Rhopaloeides odorabile, we quantified larval behaviours associated with vertical migration, phototaxis and swimming ability. We also Measured Settlement responses to cues associated with light, Settlement surface micro-topography, coral rubble and biofilms. Following an afternoon release, the majority of larvae (72%) migrated vertically to the surface (light) for 6 to 18 h. After 24 h, 55% of active larvae had moved from the surface to the bottom and maintained this position for up to 54 h before settling. Larvae did not display gregarious Settlement patterns, or a preference for Settlement surface topographies, but did preferentially settle to light-exposed surfaces. Initial Settlement to biofilms or coral rubble was higher than in controls with no cue. However, the transition from initial Settlement and attachment to metamorphosis was much higher when treatments comprised a combination of biofilm and coral rubble compared to biofilm-only treatments (49 vs. 9%). Overall, this demonstrates that hierarchical cues contribute to selective Settlement. Vertical migration to surface waters facilitates passive dispersal via wind-driven surface currents and contributes to wide-scale dispersal, while a subsequent demersal phase, where larvae actively explore the benthos for Settlement sites, enables dispersal over fine, micro-geographic spatial scales.

Whalan Steve - One of the best experts on this subject based on the ideXlab platform.

  • Larval Settlement: the role of surface topography for sessile coral reef invertebrates
    'Public Library of Science (PLoS)', 2015
    Co-Authors: Whalan Steve, Abdul Wahab, Muhammad A., Sprungala Susanne, Poole, Andrew J., De Nys Rocky
    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

  • Data from: Larval Settlement: the role of surface topography for sessile coral reef invertebrates
    2015
    Co-Authors: Whalan Steve, Abdul Wahab, Muhammad A., Sprungala Susanne, Poole, Andrew J., De Nys Rocky
    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