Why do cuttlefish Sepia esculenta enter basket traps? Space occupation habit hypothesis

SUMMARY: The sensory basis of the behavior of cuttlefish towards basket traps explains in part the mechanism of capture by the gear. Previous studies have shown that the reaction of cuttlefish Sepia esculenta to basket traps is mediated mainly by vision. In this study, visual factors that attract cuttlefish to basket traps were examined in the laboratory. The reaction of cuttlefish was divided into three processes of recognition, approach, and entry; the frequency and the duration of each process indicated the strength of the reaction. Cuttlefish were most attracted to a basket trap that contrasted most strongly with the background. When the dismantled components of the basket trap were presented as visual targets to cuttlefish, all the components were approached by the cuttlefish, which remained in the internal space. Cuttlefish have a habit of occupying the internal space of a structure and this habit seems to be the main motivation for entry into a trap. Another experiment was carried out to examine the social attraction between individuals inside and outside a trap. Social interference between males and females seems to be part of the mechanism of capture of cuttlefish by basket traps.