Eel fat stores are enough to reach the Sargasso

Abstract

It has long been assumed that the European eel (Anguilla anguilla) migrates to the Sargasso Sea — a region of the Atlantic Ocean between the Azores and the West Indies — to spawn^1,2,3. During the past decade, however, the number of glass eels has inexplicably dropped⁴, and it has been suggested that a shortage of fat stores in adults, resulting from diminished food resources for juveniles in inland waters, may prevent the starving silver eels from reaching the spawning grounds^4,5,6. But we find that the energetic cost of the 6,000-km migration is actually quite low, with 60% of the fat store remaining available for the developing gonads.