
Chinese fishers were recently treated to a bizarre surprise when they caught an odd-looking fish in Guizhou town, south-west of China. The fish head appeared to be that of a bird while the rest of its body looked like that of an ordinary fish. The stunned anglers took photos and videos which they shared widely on social media, leaving the internet in wonder.
It seemed that every concerned party had their own observation and conclusion. Some internet viewers argued that the fish’s head looked like that of a parrot or the pigeon as they pointed out what looked like a half-formed beak. This observation was also based on the fact the fish’s eyes appeared to be on both sides of the head, just like a bird’s.
Other net users pointed out that the poor fish looked more like a dolphin than a bird. They argued that it could be a breed between a dolphin and a carp, which most people found impossible. They based their conclusion on the fish’s mouth formation, eyes and the color difference between the top and bottom of its head.
The Natural History Museum said that they could not accurately identify the fish’s species (no close observation was possible as the fishermen released the fish back into the water after taking the images and photos). A fish expert at the institute, however, said that it was likely that it was a carp that had a deformed head.
The International Union for Conservation of Nature backed this conclusion by explaining that the deformation may have been a result of an injury in the early life of the fish, genetic mutations, or chemical and radioactive pollution in the water. An expert at the Guizhou Fisheries Research Institute came to the same conclusion and added that the ‘pug-head’ could also be a result of lack of enough oxygen in the water because of overcrowding of fish.
Fish researchers have found that like animals, they also suffer a variety of deformities. The common abnormalities include missing, additional or oddly-shaped fins, a curved spine, tumors and swellings, wounds and sores, poorly developed sensory organs such as the eyes, extremely long or short bodies, and abnormal color changes.
Experts explain that deformed fish are more common in aquariums and other in-breeding rearing facilities than in the open waters. This is because deformed fish that are found in seas, rivers or oceans are unable to find food and nourishment and are eaten by others, or they simply starve to death. Such fish in aquariums, however, are well taken care of as they are given food constantly and most of them grow to sexual maturity.
Fish deformities in aquariums are usually caused by factors such as overcrowding or when the space to develop is too small, poor fish diet (for instance, lack of thiaminase) and harmful chemical or radioactive components in the water or food. Diseases are also a common culprit, and those caused by mycobacteria are lethal and almost impossible to treat.

Some fish genes are also responsible for such deformities, and most aquarists euthanize deformed fish to avoid carrying the complications to the next generation of fingerlings. The fish with a bird-shaped head may survive to sexual maturity if it can fend for itself well regarding food and protection from predators. Otherwise, the poor thing will probably starve to death or make lunch for a bigger fish.