Meeting Abstract
The literature suggests that fish swimming in schools save energy compared to fish swimming alone. Each fish swimming in a group is predicted to benefit from the vortices associated with thrust production by neighboring fish, allowing each fish to maintain a given swimming speed with lower energy consumption. This is similar in concept to the energetic benefit of entraining to flow near a stationary obstruction. We tested this prediction by measuring oxygen consumption in fishes swimming singly and in small groups in a respiratory swim tunnel. In addition, we compared energy consumption in these fishes in the presence and absence of an obstruction. Both goldfish (Carassius auratus) and rainbow trout (Oncorhynchus mykiss) benefitted energetically from the presence of an obstruction. Single fish or groups of fish showed lower tailbeat frequencies and lower rates of oxygen consumption when an obstruction was present. However, both species tended to show greater energy consumption and higher tailbeat frequency with increasing number of fish in the swim tunnel. The current results suggest that group swimming does not lead to energy savings during steady swimming.
