Case file · Cryptid
The Dana's giant eel larva
In January 1930 the Danish research ship Dana netted a transparent eel larva about 1.8 m long off southern Africa, and writers reasoned that the adult would be a giant eel, a 'sea serpent' of 20 m or more.
1930 CE · -35.60, 18.50 · status: explained
The account
Eel larvae (leptocephali) are usually a few centimetres long, so a two-metre larva seemed to point to an unknown monster. The idea was repeated in sea-serpent books for decades.
The sceptical view
Later work showed that some larvae of this kind belong to notacanths (spiny eels), whose larvae grow very large and then shrink as they become adults. They are not evidence of giant eels.