Standing before the Linnean Society in 1839, the celebrated British anatomist Richard Owen delivered a detailed description of a strange new creature. Owen called it Lepidosiren annectans, an African relative of an eel-like animal that was found by the Austrian explorer Johan Natterer in the depths of the Amazon jungle in 1837. The naturalist sent two specimens back to the Vienna Museum where they were quickly described by Leopold Fitzinger under the name Lepidosiren paradoxa.
Fitzinger considered the organisms to be “perennibranchiate reptiles”, meaning that it was a primitive amphibian that did not undergo metamorphosis. Instead, according to the author of a helpful Living Age column, it remained “a gill-breathing, muddy, fishlike groveller, all the days of its life.” The animal Owen had was different,* but it was similar enough to Natterer’s specimen to allow for a close comparison of this important new genus. As a Philosophical Magazine summary of Owen’s lecture reported;
Mr. Owen observed, that since the time of the discovery of the Ornithorhynchus [duck-billed platypus] there had not been submitted to naturalists a species which proved more strongly the necessity of a knowledge of its whole organization, both external and internal, in order to arrive at a correct view of its real nature and affinities, than did the Lepidosiren …
According to Owen the Lepidosiren was a fish, a creature close to the “perennibranchiate reptiles” but more suitable as a link between cartilaginous fish (like sharks) and the “malacopterygians” (fish like the aquarium favorite the birchir). Owen’s assessment was eventually confirmed by other scientists, but it was still often presented as an extremely primitive “reptile” (i.e. amphibian) or as the “missing link” between fish and amphibians.**
Indeed, Lepidosiren was a “transitional form” that took naturalists by surprise during a time when thoughts of evolution were percolating through the scientific establishment. Even stranger, however, was the claim that in the steaming depths of the Amazon were gigantic individuals of these lungfish that regularly preyed upon large prey at the water’s edge. A December 1847 issue of the newspaper The Friend relayed the report of L.A. da Silva e Souza that the lake Padre Aranda in Brazil was home to creatures called minhocoes that “dwell in the deepest part of the lake, and have often drawn horses and horned cattle under the water.” The creatures were also reported to inhabit Lake Feia, and the local people said they were giant worms that “cause[d] animals to disappear by seizing them by the belly.”
Much of the information from this report came from a widely-reprinted paper by M. Auguste de Saint Hilaire, who had collected anecdotal evidence about the creature during his visit to the region. At first he thought tales of the monster had been inspired by a kind of electric knifefish, Gymnotus, but the local people were already familiar with this animal. A better fit, Hilaire said, was the Lepidosiren which had, of course, been first discovered in the Amazon. Anatomical investigations had revealed just how wicked the jaws of the peaceful-looking lungfish were, and perhaps there was some gigantic form haunting the rivers and lakes of Brazil. Hilaire closed his report with a plea for his fellow zoologists to visit the area to unravel the truth;
Zoologists who travel over these distant countries will do well to sojourn on the borders of the lake Feia, of the lake Padre Aranda, or of the Rio des Piloes, in order to ascertain the perfect truth–to learn precisely what the minhocao is; or whether, notwithstanding the testimony of so many persons, even of the most enlightened men, its existence should be, which is not very likely, rejected as fabulous.
Hilaire’s colleagues did not seem to be in any rush to confirm his hypothesis, but the minhocao continued to be mentioned every now and then in the scientific and popular literature. The first follow-up report would be delivered by the German entomologist Fritz Muller nearly three decades after Hilare’s notice. As reported an 1878 issue of the Popular Science Monthly (itself a summary of a report that appeared in Nature) Muller had heard that a fish three feet across was spotted along a river in Brazil. When the person who saw it went to get others, however, the animal disappeared. The party that rushed to the scene only saw the burrow the animal made in its efforts to escape.
Similar disturbances of the soil were later seen about six kilometers away, but this was a third-hand anecdote Muller had received from another German who lived in the area. Other reports of churned soil and immense burrows were commonly heard in the region, though, and Muller concluded that theywere made by a gigantic lungfish. Even so, no concrete evidence of the monster fish was found and like Hilaire he could only urge his colleagues to look into the phenomenon further.
The reports of Hilaire and Muller must have had some influence as the minhocao appeared in a number of books and periodicals. According to J. Hampden Porter the people who shared the landscape with the giant worm-fish believed that it conspired with the jaguar against humans. Indeed, it was said that some people were so scared of it they had abandoned good fishing grounds out of fear. In a compendium of sea-monster tales by Fletcher Bassett it was said to be an amphibious member of a number of mythical water monsters of the Amazon, so large that it made the water rise when it slipped into the water. (The destruction that such a creature might cause was also alluded to, oddly enough, in the book Days on Staten Island.) It even was mentioned by Jules Verne in the story The Giant Raft, and this is especially significant because some authors took Verne’s story as a primary source. All of these references are rather fleeting, however, and the reports by Muller and Hilaire remained the most detailed.
Did anyone ever catch a minhocao? According to an article in Good News in 1878 a boy caught a fish that was three feet across in an area where burrows nearly 10 feet wide had been found. Careful reading, however, reveals this to be a bastardized version of Muller’s report. The author of the article apparently mixed and matched various bits of previous anecdotal reports and conjecture to make a new story. The only original part of it was the author’s speculation that “that [the minhocao] may be a relic of the gigantic armadilloes which in past geological epochs were so abundant in South Brazil.” (This report was cannibalized for the “Table Talk” section of Gentleman’s Magazine that told its readers that proof of “gigantic cuttlefish” had recently come to light. It compared the minhocao to cephalopods, extinct marine reptiles, snakes, and prehistoric armadillos.)
As the aptly named article “A Fish With A History” stated, the tales of the minhocao were probably based upon the Lepidosiren but taken to extremes for one reason or another. This is made all the more plausible by the way the stories switched from being about a worm-like fish that devoured livestock (Hilaire) to an enormous creature that burrowed in the earth (Muller). During the time between Hilaire’s and Muller’s papers it had been discovered that some species lungfish could cocoon themselves in mucus to wait out the dry season in underground burrows, and this discovery appears to have changed the focus of the stories about the minhocao. That the anecdotes about the creature were not consistent and no specimens had been captured certainly hampered the case for its existence.
Perhaps the last of the minhocao was heard in 1894 in a Natural Science article about Lepidosiren. It barely garnered a mention, for despite all the fantastic stories it was never found. There was no reason to think it truly existed, although why such a mythology developed remains an open question. The increasingly-inaccurate reports of the animal in English periodicals can be explained, but where did the legend of giant killer lungfish first spring from?
*[And, if I am not mistaken, later turned out to belong to a different genus. Owen had previously briefly described the specimen under the genus name Protopterus in 1837 and this distinction was later upheld.]
**[I usually detest the phrase "missing link", but here it is appropriate. The discussion over the affinities of Lepidosiren/Polypterus were going on in the days before On the Origin of Species. Evolutionary language was commonly used in reference to them and Owen certainly cast them as transitional forms, yet the mechanism that affected the transition was missing. It could just as easily be said that the Lepidosiren was a result of God's desire to fill nature up and make sure there were no great gaps in nature, a vestige of the Great Chain of Being into which the fish would have fit.]
Post-Script: This post was an off-shoot of some other research I have been conducting, but it is rather strange that I forgot that the remains of an enormous extinct snake, Titanoboa, were announced this week. Titanoboa slithered through the ancient Amazon, and while I am in no way making a connection between it and the minhocao, I am surprised that I did not think of it while writing this post! See the posts by Ed, PZ, Jake, Darren, and Rebecca for more.