These are the fish that lived in prehistoric times, and managed to survive until now without much change in their appearance, so they are similar to fossils of their ancestors....
Here are the first 5-prehistoric fish,
1. Polypterus Senegalus
These African fish are often called "dinosaur eels", due to the similar appearance of reptiles and serrated dorsal fin, reminiscent of some dinosaurs dorsal spines. They are not eels, but included in the Bichir family. Bichirs been there since the Cretaceous, thus the "dinosaur" nickname for those they actually fit. Although often sold as exotic pets, the fish tend to escape from the aquarium. They can survive out of water for long periods of time as long as their skin remains wet, which enables them to wander far from the aquarium.
Polypterus Senegalus. (Picture from: http://bit.ly/1tgunR9) |
2. Alligator Gar
The predatory fish are tough and thick, can be found in the southern US and northern and eastern Mexico, this is the largest freshwater fish in North America (although it sometimes wanders into the sea). These fish can grow up to 4 meters in length and weigh up to 200 kg. Often referred to by the name Gator Gars because of their reptiles appearance and long jaws, armed with two rows of sharp teeth. They are voracious attacker predators and often bite humans, though no deaths due to bite. This fish is one of the oldest fish alive today, and their origin can be traced to the late Cretaceous period.
Alligator Gar. (Picture from: http://bit.ly/100N6ph) |
3. Sawfish
These endangered animals are one of the fish that survived the Cretaceous period, and can be found both in saltwater or in rivers and creeks, and has been found up to 100 km further inland. The length can reach 7 meters, sawfish may look like sharks. Their "saw" function as a weapon as well as a sensory organ, which has pores of electro-sensitivity that allows them to find their prey because their vision is myopic. Although usually calm, sawfish can become extremely dangerous if provoked. From fossil ever found, the prehistoric sawfish is the prey of Spinosaurus, the largest carnivorous dinosaur, because the ancestors of sawfish found tucked between the dinosaur's teeth.
Sawfish. (Picture from: http://bit.ly/1DtTeDy) |
4. Coelacanth
Coelacanth is the most famous of all "living fossils fish" and deserves to be number one in this list, because this is the best example of a "Lazarus taxon". This animals that should be long extinct and unexpectedly found to be alive. The coelacanth was supposed to have become extinct in the Cretaceous period, along with the dinosaurs, but in 1938, a live specimen was caught in South Africa. Since then, more specimens were seen and photographed, and a second coelacanth species was even found in Indonesia in 1999. The coelacanth is a large predator, can reach a length of 2 meters, they eat smaller fish, including small sharks, and are usually found in deep, dark waters. Although rarely captured and consumed because it tastes bad, but the existence of the coelacanth is now endangered.
Coelacanth. (Picture from: http://on.natgeo.com/1eq3aaQ) |
5. Frilled Shark
It is a deep sea predator and one of the most primitive sharks alive today, is a relic from the Cretaceous period, when dinosaurs ruled the Earth. Seldom seen alive, and only recently filmed for the first time, the frilled shark can grow up to a length of 2 meters (with females larger than males) and they live in deep waters. Their food is usually a squid.
They are harmless to humans, but most frayed sharks spent their entire lives without ever seeing a human being. Only dead or dying specimens are usually seen and recorded by fishermen or scientists. (Jump to 2nd part.) *** [EKA | FROM VARIOUS SOURCES]
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Frilled Shark. (Picture from: http://bit.ly/10xYWIJ) |