Crested-horn shark feeding on Port-Jackson shark egg, Sydney, Australia

Crested-horn sharks (heterodontus galeatus) sometimes feed on eggs from Port-Jackson sharks (heterodontus portus jacksoni), a similar-looking yet larger species of sharks. This evening in Cabbage Tree Bay (North Sydney, Australia), I stumbled upon this opportunistic individual, which struggled to eat the rival species’ egg, seemingly too big. After minutes of frustrating attempts, the shark surprisingly "stood up", maybe in an attempt to use gravity to get its meal through.