The aspidochelone, the whale mistaken for an island
Sailors anchor on an island that turns out to be a sea monster: the story of the aspidochelone from the Physiologus to Saint Brendan and Sinbad.
A ship in mid-ocean sights an island. The weary sailors land on it, drop anchor, go ashore and light a fire to cook. But the island moves: it is the back of an enormous sea creature which, feeling the heat, dives into the depths, dragging men and ship down with it. This story, one of the most striking in the bestiaries, bears the name aspidochelone and spread remarkably widely, from Greek tradition to Arabic and Celtic literature.
The name and the two natures
Aspidochelone is a Greek compound name, joining the asp and the turtle, chelone, probably in reference to the creature’s leathery, shield-like back. In the Latin bestiaries the animal is often called simply cetus, the whale, or the island-whale. In Old English the Exeter Book devotes a short poem to it, in which the monster is named Fastitocalon, a corrupt form of the Greek term.
The Physiologus ascribes two natures to it. The first is that of the deceptive island that sinks with the sailors. The second concerns food: when it is hungry, the whale opens its mouth and gives off a very sweet smell, which attracts small fish; these swim into its jaws and are swallowed. The large, mature fish, by contrast, keep well away.
The devil disguised as a shelter
The interpretation is unanimous throughout the tradition. The whale is the devil, who presents himself as a safe and welcoming place to rest. Whoever trusts him, like the sailors lighting a fire on the false island, is dragged down into the abyss of hell. The scent that attracts the small fish is the seduction of worldly pleasures, which captures souls weak in faith, while firm and mature believers recognise the deception and keep their distance.
In the illuminated bestiaries the scene is painted with great liveliness: the moored ship, the sailors cooking, the whale’s back sometimes covered with trees and grass, the monster’s snout rising from the water. Some illuminators, such as those of the Rochester Bestiary, made it one of the most memorable pages of the manuscript.
Saint Brendan, Sinbad and Milton
The same image recurs outside the bestiaries with different meanings. In the Navigatio sancti Brendani, the Latin account of the Irish saint’s voyage, probably written between the ninth and tenth centuries, the monks land on an island, light a fire and discover that it is a huge fish named Jasconius. Here, however, the whale is not diabolical: every year the monks celebrate Easter on its back, and the animal becomes almost a docile servant of the divine plan.
The motif also appears in the Thousand and One Nights, in the first voyage of Sinbad the Sailor, who lands with his companions on an island that turns out to be a great fish. As late as 1667 John Milton, in the first book of Paradise Lost, compares Satan to the Leviathan on whose back an unwary pilot casts anchor believing it an island, deliberately taking up the image of the bestiaries.
The success of the aspidochelone is explained by the universal force of its story. Behind the image there may lie sailors’ real experience of large whales surfacing, but the symbolic core runs deeper: the greatest danger is not what looks threatening, but what presents itself as a refuge. It is a lesson the bestiaries entrusted to one of their most memorable creatures.