Camouflaged and Watchful: Stonefish Escape Behavior on Crowded Reefs

Understanding escape behavior in cryptic and venomous reef fishes is critical for both ecological theory and public safety in coastal environments. We quantified the Flight Initiation Distance (FID) of 65 individual stonefish (Synanceia spp.) across four public beaches in Eilat, Israel, between March and May 2025. Initial Identification Distance (Initial ID) ranged from 0.5 to 3.5 m, whereas FID was consistently short (0.0–0.6 m), with 62% of individuals (n = 40) showing no flight response. Logistic regression revealed that the probability of fleeing was positively predicted by Alert behavior (p = 0.005), while Initial ID and site were not significant. Among individuals that did flee (n = 25), FID remained short and showed no significant spatial variation. A linear model confirmed Alert as the only positive predictor of FID (p = 0.045), while other variables were non-significant. These findings demonstrate that stonefish predominantly rely on crypsis and venom rather than active escape, resulting in minimal or absent flight responses. This lack of FID highlights their unique defensive strategy among reef fishes but also increases the risk of accidental human envenomation in areas of high recreational activity. Monitoring FID patterns may serve as a behavioral indicator of anthropogenic disturbance, while also informing conservation and public safety strategies in urban reef environments.