Tuesday, September 14, 2010

What the fish? Alive even after a MILLION years!

Top 10 Prehistoric Fish Alive Today

10 Hagfish

According to the fossil record, hagfish have existed for over 300
million years, which means they were already old when dinosaurs took
over the world! Found in relatively deep waters, these animals are
sometimes called slime eels, but they are not really eels, and
actually, they may not even be fish at all,according to some
scientists. They are very bizarre animals in all regards; they have a
skull but lack a spine, and they have two brains. Almost blind, they
feed at night on the carcasses of large animals (fish, cetaceans etc)
which fall to the sea bottom. They owe their “slime
eel” nickname to the fact that they produce a slimey
substance to damage the gills of predatory fish; as a result, they have
virtually no natural enemies. 
9 Lancetfish

The lancetfish has a very obvious “prehistoric”
appearance, with those fierce-looking, sharp teeth on its jaws and the
sail on its back, reminiscent of that of some dinosaurs (although, in
the lancetfish the sail is actually an enlarged dorsal fin). Even its
scientific name has a dinosaurian sound to it (Alepisaurus ferox). Up
to two meters (6' 6?) in length, this predator is found in all the
oceans except for polar regions; very voracious, it feeds on smaller
fish and squid, and has known to feed on members of its own species
8 Arowana

Belonging to the ancient group of the Osteoglossids, these fish already
existed in the Jurassic period. Today, they are found in the Amazon,
and in parts of Africa, Asia and Australia. Sometimes kept as exotic
pets, arowanas are voracious predators that feed on any small animal
they can catch, including birds and bats which they catch in mid flight
(they are able to leap up to 2 meters (6' 6?) into the air). In China,
arowanas are known as “dragon-fish” due to their
appearance, and they are thought to be harbingers of good luck.
7 Frilled Shark
This deep sea predator, 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 2 meters (6' 6?) (with females being
larger than males) and they live in deep waters, where they feed mostly
on squid. They are not dangerous to humans, and as a matter of fact,
most frilled sharks spend their whole lives without seeing a human
being. Only dead or dying specimens are usually seen and recorded by
fishermen or scientists.
6 Sturgeon
Another survivor from the age of dinosaurs (they were already around in
the early Jurassic), the sturgeon is well known for being one of the
main sources of caviar (which is made out of their roe or egg masses);
due to overfishing, these magnificent, armored fish are sadly
endangered nowadays. The largest sturgeon species can grow up to 6
meters (19' 7?) long, being as large as most great white sharks; they
feed on small animals from the sea bottom and pose no danger to humans,
unless provoked (although they are so big that they have hurt, and even
killed, people unintentionally by leaping out of the water and landing
on boats!)
5 Arapaima
A close relative to the arowana (see #8), the Amazonian arapaima is
sometimes considered to be the largest freshwater fish in the world.
According to early descriptions, it could grow up to 4.5 meters (14'
8?) long, but today, enormous individuals like these are seldom found
and most adult arapaimas average 2 meters (6' 6?) long. These slow
moving predators feed on smaller fish, crustaceans and whatever small
animal they can fit in their mouth. An interesting trait of this fish
is that it needs to breath oxygen from the air, like a cetacean, in
order to survive. Arapaimas pose no danger to humans and are often
hunted for their meat; unfortunately, they are very scarce nowadays.
Although the arapaima seemingly appeared in the Miocene period, it
belongs to a much older family, the Osteoglossidae, and therefore its
origins can be traced back to the age of dinosaurs.
4 Sawfish
This critically endangered animal is a survivor from the Cretaceous
period, and can be found both in saltwater or in rivers and creeks, and
has been found up to 100 kms inland. Up to 7 meters (23') in length,
sawfish may look like sharks but are actually more closely related to
rays. Their “saw” is both a weapon and a sensory
organ, covered on electro-sensitive pores which allow it to sense prey
despite its terrible eyesight. Although usually peaceful, the sawfish
can become extremely dangerous if provoked. Due to an extraordinary
fossil, we know that gigantic, prehistoric sawfish were probably a
staple food for the largest carnivorous dinosaur, Spinosaurus, as a
vertebra from the fish was found stuck between the dinosaur’s
3 Alligator Gar
This formidable, thick scaled predator is found in the southern US and
northern and eastern Mexico, being the largest freshwater fish in North
America (although it sometimes wanders into the sea). It can grow up to
4 meters (13') long and weigh up to 200 kgs (440lbs). Gator gars are so
called because of their reptilian appearance and long jaws, armed with
a double row of sharp teeth. They are voracious ambush predators and
have been known to bite humans on occasion, although no confirmed
deaths due to alligator gars have been recorded to date. Gars are among
the oldest fish alive today; their origins can be traced back to the
Cretaceous period.
2 Polypterus Senegalus
These african fish are often called “dinosaur
eels”, due to their reptilian appearance and serrated dorsal
fin, reminiscent of some dinosaurs’ spiked backs. They are
not really eels, but members of the bichir family. Bichirs were already
around in the Cretaceous, so the “dinosaur” part of
their name is actually fitting in a way. Although often sold as exotic
pets, dinosaur eels are prone to escaping their fish tanks. They can
survive out of the water for long periods of time as long as their skin
remains wet, which enables them to wander far away from their tank.
1 Coelacanth
The Coelacanth is the most famous of all “living
fossils” and deserves to be #1 in this list, because it is
the best example of a “Lazarus taxon”, this is,
animals that were supposed to be long extinct and are unexpectedly
found to be alive. Coelacanths were 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 have
been seen and photographed, and a second coelacanth species was even
found in Indonesia in 1999. Coelacanths are large predators, up to 2
meters (6' 6') long; they feed on smaller fish, including small sharks,
and are usually found in deep, dark waters. Although rarely captured
and consumed due to their horrible taste, coelacanths are critically
endangered nowadays.
Hagfish , Lancetfish , Arowana , Frilled Shark , Sturgeon , Arapaima ,
Sawfish , Alligator Gar , Polypterus Senegalus , Coelacanth , Lazarus
taxon , Prehistoric Fish

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