Diel activity patterns and habitat preferences of stonefish (Synanceia spp.) in captivity

Abstract

Synanceia verrucosa (reef stonefish) and Synanceia horrida (estuarine stonefish) are known as the world’s most venomous fishes. However, little is known about their habitat preference and activity patterns. This study aimed to determine the habitat preferences and diel activity patterns of stonefish. The movements of four adults of each species that were offered complex and simple habitats in captivity were recorded by filming during day and night periods. Generally, both species exhibited similar behaviour, though S. verrucosa travelled further per movement than S. horrida. Collectively, stonefish spent 94% of their time associated with complex habitat and moved significantly less frequently on complex (1.6 movements per hour) relative to simple habitat (17.3 movements per hour). Stonefish were least active around sunset in the late afternoon and evening, which may relate to an active feeding period during the morning or paradoxically to a higher probability of ambush feeding success near sunset. These findings have enhanced our current understanding of the ecology of these species.