Aristotle [ca. 350 BCE] (De animalibus, Book 8, 20.12; 8, 25.6): [Book 8, 20.12] No pestilential disease attacks river and pond fish, though some of them are subject to peculiar diseases, as the glanis, from its swimming near the surface, appears to be star-struck by the dog-star, and it is stupefied by loud thunder. [Book 8, 25.6] Among river fish the male glanis is very careful of his young fry, but the female goes away as soon as she has deposited her ova, but the male continues to watch by the greater number of the ova, paying them no more attention than to drive away other fish, that they may not carry away the ova; he is thus employed for forty or fifty days, until the young fry are so far grown that they can escape from other fish; the fishermen know when it is guarding its ova, for it drives away other fish, and as it jumps at them it makes a noise and a murmur. It remains with such affection beside its ova, that if they are deposited in deep water, and the fishermen attempt to bring them into shallow water, the fish will not forsake them; but if young it is easily taken with a hook, from its habit of seizing upon any fish that may come in its way; but if it is experienced, and has swallowed a hook before, it does not leave its ova, but with its hard teeth it will bite and destroy the hook. - [Cresswell translation, 1887]

Pliny the Elder [1st century CE] (Natural History, Book 9, 17; 9, 24; Book 9, 67): [Book 9, 17] The catfish ranges about and goes for every living creature wherever it is, often dragging down horses when swimming. [Book 9, 24] Of river fish the catfish has a stroke at the rise of the dogstar, and at other times is always made drowsy by lightning. [Book 9, 67] The fish called the catfish (cautius) more cautiously nibbles at hooks from behind and strips them of the bait without swallowing them. - [Rackham translation]

Thomas of Cantimpré [circa 1200-1272 CE] (Liber de natura rerum, Marine monsters 6.25; Fish 7.21; 7.76): [Thomas describes the catfish under the names gamanez, clautius and siluris, and is both a marine monster and a fish.] [Marine monsters 6.25] Gamanez is a monster, as Aristotle says, that remains in river waters. The male of this monster has the greatest concern about his offspring, but the female neglects them and withdraws and wanders through the waters. Then the male, with his natural sense of duty to his offspring, watches over them until they grow up and have the strength to flee from their adversaries, which are the other fish. In the mean time, however, the father builds a kind of structure around the children, by which they are protected during their youth. But in order that his adversaries might be frightened, he cries out strongly; and he is anxious all the time about them. But if at that time it happens that he falls into a net by accident, he tears the net with his strong teeth, and escapes by strength rather than by courage, since longing for his children animates him to unusual strength. [Fish 7.21] Clautius, which is called glanis (catfish), as Pliny says, turns away and bites the baited hooks, and does not swallow them, but robs them of their bait. This fish signifies those who, although they openly shun the vice of fornication, lest they should perhaps be caught in the knowledge of their offspring, yet are most impudently defiled by the very circumstances of fornication, such as kisses, gossips, illicit and most wicked contortions.. [Fish 7.76] The catfish, as Pliny says, is a fish that has a wonderful concern for its offspring. For after the female gives birth, within three days the male guards the eggs for fifty days, lest they be taken by others. The catfish roams around, and wherever it is, it wants to overcome everything that comes its way. - [Badke translation/paraphrase]