2018 Volume 84 Issue 3 Pages 377-383
We aimed to quantitatively determine the relation between the attractive force of seaweed (Sargassum) acting on juvenile Sebastes cheni and the density of the seaweed. The seaweed was placed in the center (1.2 m in diameter) of a circular aquarium (4.8 m in diameter) at different densities, and swim-tracking of the fish by an LED was captured on video for ten minutes. The position of the fish was taken from the captured video in about 0.1-second increments. Parameters of random swimming behavior (swimming speed and turning angle) for an agent-based model were determined in a no-seaweed experiment. The distribution pattern of the fish in each seaweed density experiment was calculated by changing the attractive force of the seaweed by trial and error. The distribution pattern of juvenile S. cheni in the aquarium was affected by the seaweed density. Computed results showed that the relative magnitude of the attractive force of the seaweed to a random swimming vector increased from 8% at 22 plants/m2 to 12-13% at 86 plants/m2.
