The hafgufa is a mysterious sea monster described in Konungs skuggsjá ('The King's Mirror'), which is a mid-13th-Century Old Norse manuscripts – but that is not all. It has actually been traced back as far as an account in a 2nd-Century-AD text from Alexandria, Egypt, entitled Physiologus, whose text is accompanied by illustrations of a whale-like creature termed the aspidochelone, depicted with its huge mouth wide open and fishes jumping into it.
According to The King's Mirror:
It is said of the nature of this fish [the hafgufa] that, when it goes to feed, it gives a great belch out of its throat, along with which comes a great deal of food. All sorts of nearby fish gather, both small and large, seeking there to acquire food and good sustenance. But the big fish keeps its mouth open for a time, no more or less wide than a large sound or fjord, and unknowing and unheeding, the fish rush in in their numbers. And when its belly and mouth are full, [it] closes its mouth, thus catching and hiding inside it all the prey that had come seeking food”
The hafgufa is also mentioned in various other Norse manuscripts from this same period. Moreover, a similar description for the aspidochelone is given as follows in Physiologus:
When it is hungry it opens its mouth and exhales a certain kind of good-smelling odor from its mouth, the smell of which, once the smaller fish have perceived it, they gather themselves in its mouth. But when his mouth is filled with diverse little fish, he suddenly closes his mouth and swallows them.
In the scientific age, there has been much speculation and dispute as to whether the hafgufa was based upon a real creature, and, if so, what that creature might be, with the consensus being that it was probably some kraken-like monster.
Now, however, this maritime mystery beast's true nature may at last have been revealed, thanks to the publicising of a remarkable mode of feeding behaviour practised by various rorqual whales.
Known as trap feeding and first scientifically recorded in 2010, various humpback whales Megaptera novaeangliae and Bryde's whales Balaenoptera brydei have been observed waiting motionless at the water surface in an upright position with their huge mouths wide open, into which shoals of fishes unsuspectingly swim to their doom, fatally mistaking the whales' gaping jaws for shelter, until the jaws close, engulfing them!
Moreover, this eyecatching activity has lately attracted worldwide attention thanks to an Instagram video clip of a Bryde's whale performing it that went vital after featuring in a 2021 BBC wildlife documentary (click here to view this clip).
According to the Norse manuscripts, as noted above, the hafgufa behaves in a similar manner, even actively attracting shoals of fishes to swim into its open mouth by emitting a specific perfume. And sure enough, when seeking to lure fishes into their mouths by regurgitating food, both the humpback and Bryde's whales produce a distinct smell.
A detailed study examining and comparing medieval Norse accounts of the hafgufa with modern-day reports of trap feeding by rorquals was published on 28 February 2023 in the journal Marine Mammal Science (click here to read it). The paper was co-authored by maritime archaeologist John McCarthy, from the College of Humanities, Arts and Social Sciences at Flinders University in Australia, who had become interested in this correlation after reading about the hafgufa in traditional Norse mythology.
Once again, therefore, it seems likely that an ostensibly fabulous monster of mythology can lay claim to a firm basis in mainstream zoological fact after all.