ABSTRACT
A. latespinosus has a nocturnal activity with two peaks at dawn and at dusk, like the other species of the genus Astropecten. The sea star burrows in sand during its resting time and goes around the bottom surface in search of preys (mainly bivalves and snails) during its active time. A fundamental pattern of feeding behaviour is divided into the following five components: 1) searching behaviour, 2) approaching after detecting a prey, 3) holding and conveying the prey to its mouth, 4) swallowing and 5) resting till the start of the next feeding behaviour. The total time taken to complete the components from 2) to 5) ranged from 3′15″ to 6′49″ and 4′44″ in average. The detectable ability of the sea star reaches at least 8 cm from the centre of the animal. The sea star, which has no anus, fundamentally repeats the feeding mode of engulfing preys and ejecting the indigestible shells of the prey. Usually, the sea star swallows preys at night and ejects their shells during the burrowing time from noon to the starting time of feeding. The daily searching area for the individual of a population was estimated at 1.28–1.92 m2, using the detectable distance and the distance of daily moving for the calculation. Taking the natural density (1.28/m2) of the sea stars into consideration, the daily searching area of the natural population of the sea star is calculated at 1.6–2.5 times of the bottom area. Consequently, the preys in the habitats of the sea star suffer severely from the predation of the sea star.
