10 most difficult fish riddles

Eel catfish is an airbreathing catfishes found in Africa. It grows up to about 33 centimeters. It lives in the muddy swamps of Congo and Angola. The main component of its diet are land beetles living on land. Scientists hope that the discovery of this fish will allow us to understand the evolution of sea fish to terrestrial animals in the Devonian period. Their hunting method is probably similar to the methods of early vertebrates.

In the 1990s several cod stocks collapsed due to overfishing. With the large predatory fish removed, their prey have undergone population explosions, and the capture of lobster has tripled since 1970.

Electric eel lives in muddy floodplains of Orinoco basin. It is well adapted to this low-oxygen environment: it can breathe atmospheric air using a vascularized respiratory organ in its oral cavity. In fact, electric eels must rise to the surface every 10 minutes and inhale, otherwise they die not having enough oxygen from the gill.

Surface lures are also known as top water lures, poppers and stickbaits. They float and look like fish prey that is on top of the water. They can make a popping, burbling, or even a buzzing sound. It takes a long time to learn how to use this lure effectively

Dunkleosteus is an extinct genus of arthrodire placoderm fish that existed during the Late Devonian period, about 358–382 million years ago. Some of which are among the largest placoderms to have ever lived. The largest species, D. terrelli grew up to 6 m (19.7 ft) long and 1 t (1.1 short tons) in weight. Numerous fossils of the various species have been found in North America, Poland, and Morocco.

Koi was bred in the 18th century in Japan. Since then, more than 120 varieties of this fish have been created by cross-breeding.

The arapaima, pirarucu, or paiche are any large species of bonytongue in the genus Arapaima native to the Amazon and Essequibo basins of South America. Genus Arapaima is the type genus of the family Arapaimidae. They are among the world's largest freshwater fish, reaching as much as 3 m (9.8 ft).

The slender snipe eel (Nemichthys scolopaceus) is a fish that can weigh only a few ounces, yet reach 5 feet or 1.5 m in length. Features include a bird-like beak with curving tips, covered with tiny hooked teeth, which they use to sweep through the water to catch shrimp and other crustaceans. It has more vertebrae in its backbone than any other animal, around 750.

The garfish is found in brackish and marine waters of the Atlantic Ocean and the Mediterranean, Caribbean, Black, and Baltic Seas. It is a long and slender fish with a laterally compressed body. They have unusual green bones (due to the presence of biliverdin) which discourages many people from eating them, but the green colour is harmless.

Clocked at speeds in excess of 68 mph, some experts consider the sailfish the fastest fish in the world. Easily recognized, sailfish are named for the spectacular sail-like dorsal fin that extends for nearly the entire length of their silver-blue body. Additionally, the sailfish's upper jaw is far longer than its lower jaw, forming a distinctive bill that looks like—and sometimes acts like—a spear.