Variations: Trebius Niger (Black Trebius), Trebeus, Swordfish
Within his discussion of the echeneis or remora, Pliny digresses briefly to mention the murex, a seashell that also can adhere to ships and prevent them from moving. He then credits Trebius Niger with the knowledge that the echeneis is a foot long, five fingers thick, and capable of hindering the movement of a ship; if preserved in salt, it can draw up gold that has fallen down a deep well.
The next paragraph addresses a miscellany of fishes. The mena changes color, becoming white in winter and black in summer. The phycis (a goby or lamprey) also changes color; it is also the only fish that builds a nest of seaweed to spawn in.
Thomas de Cantimpré combines all those accounts and misreads the name of Pliny’s source for the name of a fish. This miraculous textual transformation is the origin of the trebius niger or black trebius. This composite fish is a foot long, black in color and changing to white depending on the season. It can hinder ships like a remora, and even a small salted piece of it can draw gold out of wells. Unlike other fishes, the trebius builds a nest to lay its eggs in.
After having decided that the trebius is a fish, Thomas sticks to his interpretation. A later passage cites Trebius Niger and describes swordfish attacks on boats. This is again read to be an allusion to the trebius, and, as a result, it becomes armed with a sharp beak that it uses to sink ships (despite its size, apparently).
The trebius is shown nesting in a tree in the Hortus Sanitatis. Albertus Magnus gives us the most memorable depiction of the fish, giving it a pointed nose, a beard, clawed feet, and a nest with an egg inside.
References
Aiken, P. (1947) The Animal History of Albertus Magnus and Thomas of Cantimpré. Speculum, 22(2), pp. 205-225.
de Cantimpré, T. (1280) Liber de natura rerum. Bibliothèque municipale de Valenciennes.
Cuba, J. (1539) Le iardin de santé. Philippe le Noir, Paris.
Magnus, A. (1545) Thierbuch. Jacob, Frankfurt.
Magnus, A. (1920) De Animalibus Libri XXVI. Aschendorffschen Verlagbuchhandlung, Münster.
Pliny; Holland, P. trans. (1847) Pliny’s Natural History. George Barclay, Castle Street, Leicester Square.
Unknown. (1538) Ortus Sanitatis. Joannes de Cereto de Tridino.