There are many stories about one terrible catfish. A toothless, scaleless, merciless catfish capable of the abominable. It is said that this catfish can climb trough the human urethra to feed its insatiable thirst for blood. A fish so terrible that George Myers named a relative of it Urinophilus diabolicus (Myers 1927), in reference to its association to the devil and its scary abilities. Of course, I am not talking about the wels catfish. That is another story.
Two fishermen were reported to reel one enormous catfish in Italy last week (CNN report). Dino and Dario Ferrari. Both Italian. Both boosting youth and energy, and the finest fishing equipment (wink). So what do we know about this catfish? The fish in question is a beautiful specimen of Silurus glanis Linnaeus 1758. This catfish was described by the father of nomenclature himself, more than one hundred years before Johann Strauss II composed the famous melody associated to weddings in many countries around the world. The wels catfish is native to the Danube River and was introduced in reservoirs of Italy and Spain in the 1980s where it has established healthy populations, based on the reports of large size specimens caught in the region. The catfish in question might not be the largest caught, but it is “possibly” the largest reeled. The International Game Fish Association established regulations for fish catches to count as records. For the fish to be a record the fishing has to be done by one person, with no help, and preferably there should be at least one witness that can state that the activity was conducted under such regulations. Just like golf. If I hit a ball into a hazard, take a Mulligan, and then get the ball in the hole with one shot in a par three, I can only say that it could have been a hole in one. But it wasn’t.
The wels catfish is one of 15 species in the genus Silurus, with species inhabiting rivers in Europe and Asia. There is even one species of Silurus in Japan! Like most of its relatives, it doesn’t have scales. Like most of its relatives it doesn’t have teeth like alligators or mammals do. But they do have teeth. Tiny little needle-like teeth, arranged in patches over the premaxillary and dentary bones. Picture this: your upper jaw is made out of two bones that hold teeth. They are attached together in the middle by a suture. These bones are the maxillary (upper jaw) and the dentary (lower jaw). Catfishes have maxilla and premaxilla, whereas the premaxilla is exactly where you expect it to be: anterior to the maxilla. An extra pair of bones, closer to the midline than the maxillary bones, that we don’t have. So now that you can picture the location of the premaxilla on a catfish, think about this bone as a very wide rectangular brush. Like one of those you would use to comb your cat’s fur. The ones with bent needles. That is what catfish teeth look like. This is, actually, a type of teeth not uncommon in fishes. These teeth feel like sand paper to the touch. The coarsest sand paper you’ve ever seen. These teeth are also found in the lower jaw of the catfish, on the dentary, named like the bone that makes up your own lower jaw. The wels catfish is a beautiful gentle giant with a tiny dorsal fin and an extremely long anal fin. Its little beady eyes are probably not the most powerful tools to capture prey, but together with the latero-sensory canals and taste buds that cover its body the job gets done.
The catfish Silurus glanis has been reported to eat pigeons in France. After observing the results of 45 attempts at capturing pigeons, 28% of them were accounted as successful events. Good for the catfish. So, wouldn’t it be a great idea to test the myth and conduct experiment? What about 100 healthy adults shuffling their feet in the waters of the Po River. Or even better! How about 100 adults rolling naked on the bottom of a sandy river in the Amazon basin (that is the requisite, the candiru cannot get through spandex) in the name of science. Volunteers?
If you are interested in this type of stories, there is a fascinating book about the candiru by Steven Spotte (Candiru: Life and Legend of the Bloodsucking catfishes). I will not spoil it for you.