Body size and substrate type modulate movement by the western Pacific crown-of-thorns starfish, Acanthaster solaris

The movement capacity of the crown-of-thorns starfishes (<em>Acanthaster</em> spp.) is a primary determinant of both their distribution and impact on coral assemblages. We quantified individual movement rates for the Pacific crown-of-thorns starfish (<em>Acanthaster solaris</em>) ranging in size from 75–480 mm total diameter, across three different substrates (sand, flat consolidated pavement, and coral rubble) on the northern Great Barrier Reef. The mean (±SE) rate of movement for smaller (<150 mm total diameter) <em>A</em>. <em>solaris</em> was 23.99 ± 1.02 cm/ min and 33.41 ± 1.49 cm/ min for individuals >350 mm total diameter. Mean (±SE) rates of movement varied with substrate type, being much higher on sand (36.53 ± 1.31 cm/ min) compared to consolidated pavement (28.04 ± 1.15 cm/ min) and slowest across coral rubble (17.25 ± 0.63 cm/ min). If average rates of movement measured here can be sustained, in combination with strong directionality, displacement distances of adult <em>A</em>. <em>solaris</em> could range from 250–520 m/ day, depending on the prevailing substrate. Sustained movement of <em>A</em>. <em>solaris</em> is, however, likely to be highly constrained by habitat heterogeneity, energetic constraints, resource availability, and diurnal patterns of activity, thereby limiting their capacity to move between reefs or habitats.