Whale shark foraging on baitfish off Djibouti

Abstract

In the Gulf of Tadjoura, Republic of Djibouti, whale sharks (Rhincodon typus Smith, 1828) are known to feed on a wide variety of zooplankton organisms. However, for the first time in this area, seven juvenile whale sharks were filmed feeding on a school of baitfish (anchovies). During the event, zooplankton samples were collected and biomass was calculated. Results support the hypothesis that when dense patches of zooplankton are not available in the Gulf of Tadjoura, whale sharks remain in the area and feed on alternative energy-rich prey, such as baitfish, to meet their energetic demands.