Aspidochelone

No matter what form it is, it is always described as being so huge that it is often mistaken for a rocky island covered with sand dunes and vegetation.

The name aspidochelone appears to be a compound word combining Greek aspis (which means either "asp" or "shield"), and chelone, the turtle.

It rises to the surface from the depths of the sea, and entices unwitting sailors with its island appearance to make landfall on its huge shell and then the whale is able to pull them under the ocean, ship and all the people, drowning them.

Pliny the Elder's Natural History tells the story of a giant fish, which he names pristis, of immense size.

[10] The Arabic polymath Al-Jahiz, writer of Kitāb al-Hayawān (The Book of Animals), mentions three monsters that are supposed to live in the sea: the tanin (sea-dragon), the saratan (سرطان, or saraṭān, "crab") and the bala (whale).

About the saratan, he said the following: This monster is also mentioned in The Wonders of Creation, written by al-Qazwini, and in the first voyage of Sinbad the Sailor in One Thousand and One Nights.

Borges describes saratans as having long-life spans and incredible size, to the point where their shells can be mistaken easily enough as small islands.

They race to their ship, and Brendan explains that the moving island is really Jasconius, who labors unsuccessfully to put its tail in its mouth.

[21] According to John McCarthy et al. (2023) the myth of Aspidochelone could be explained by cetacean trap feeding, a behaviour, for example, viewed in rorqual whales (Balaenopteridae).

[22] This research was also mentioned on March 28, 2024 in the German TV-quiz-show “Wer weiss denn sowas“ (minute 26:00 ff.).