Menu

Giant Air-Breathing Fish Discovered in Amazon

giant-amazon-river-fish

Scientists have found a new species of giant, air-breathing fish in Brazils Amazon River the first discovery of its kind in more than 150 years.
The silver fish is a member of the arapaima family, an air-breathing freshwater fish native to the rivers of the Amazon Rain forest that can grow up to 10 feet long.

It is the first new arapaima species to be discovered since 1847, according to National Geographic.
The discovery was reported in the journal Copeia.

The newly-discovered A. leptosome has a slender body, distinct sensory cavities on the head, a sheath that covers part of the dorsal fin and a unique color pattern.

Four species of arapaima were recognized by scientists in the 1800s, but were lumped into one by British scientist Albert Gunther in 1848 a prevailing wisdom that had largely gone unchallenged until recently.

Dr. Donald Stewart of the SUNY College of Environmental Science and Forestry in Syracuse, N.Y., has shown that there are actually five species of the giant fish, and made the most recent discovery.

Until this year, no taxonomist has questioned Gunthers opinion about these iconic fishes, he wrote in his findings.
Identifying and understanding all of the arapaimas different features will aid in the health of the fish, the conservation of river ecology and the balance of nature, according to Stewart.

There is a growing aquaculture industry for arapaima, so they are being moved about and stocked in ponds for rearing, he said. Eventually, pond-reared fishes escape and, once freed, the ecological effects are irreversible. A species that is endangered in its native habitat may become an invasive species in another habitat.

The bottom line is that we shouldnt be moving these large, predatory fishes around until the species and their natural distributions are better known. Given the uncertainties, precaution is needed.

However the latest findings called this view into question.

The new fish, dubbed Arapaima leptosome, has several distinguishing features, including an elongated sensory cavity on the head, a sheath that covers part of the dorsal fin and distinctive markings on its skin.

Although it was first discovered back in 2001, it has taken this long for the fish to be officially classified.

The discovery and subsequent classification means there are now five known species of arapaima.

The most recent species was found where the Brazilian Solimoes and Purus rivers join.

Everybody for 160 years had been saying theres only one kind of arapaima. But we know now there are various species, including some not previously recognised, said Dr. Donald Stewart of the SUNY College of Environmental Science and Forestry, who made the discovery.

In separate research, experts have also studied the scales of the fish and discovered they consist of stacked spiral staircase-like layers made of collagen, protected by a hard outer shell.

These spiral layers intertwine and curve inward and outward meaning they can repel the force of the piranhas tiny sharp teeth and researchers believe the scales have evolved in this way.

hqdefault

The team from Lawrence Berkeley National Laboratory wanted to know how the fish evolved to live in relative peace with the flesh-eating predators.

They studied the scales to the highest resolution microscopic level ever used in experiments of this kind and discovered each individual scale is made up of a series of layers.

A single scale has a hard outer shell, around 0.5mm thick, on top of a soft inner core that is double the thickness of its protective layer.

They studied the scales to the highest resolution microscopic level ever used in experiments of this kind and discovered each individual scale is made up of a series of layers.

A single scale has a hard outer shell, around 0.5mm thick, on top of a soft inner core that is double the thickness of its protective layer.

2246275001_9130df72f5

The core is made up of elastic collagen shaped by multiple staircase-like structures that curve in and around each other.

The outer shell can protect the fish from initial contact from the bite, but if the teeth shatter the brittle casing, the softer core has evolved to repel the force of the bite.

To test the scales, researchers simulated piranha bites along the row to see how the teeth penetrated them.
They found the scales overlap each other by about 60 per cent and this adds an extra layer of protection because a piranha tooth is able to break one scale, but rarely two.

Study co-author Bernd Gludovatz from the laboratory told Live Science: The beauty of the structure is when you apply a load in a certain direction, the spiral stairs have the ability to rotate, and can modify the loads you have applied to the entire sample to withstand the loads.

We want to understand how nature develops these materials, and then try to copy them and make something similar and, if possible, get the mechanical properties maybe even better and more efficient.
The findings are published in journal Nature Communications.

arapaima-diver_214_600x450

WHAT IS THE ARAPAIMA GIGAS?

The Arapaima gigas is a species of fish found in the Amazon River basin in Brazil.

They are the largest freshwater fish in South America and can grow to around 6ft 7in, although many peak at around 6ft long.
The fish has large black and green scales with red markings.
It is known locally as paiche, which means red fish.
The new fish, dubbed Arapaima leptosome, has several distinguishing features, including an elongated sensory cavity on the head, a sheath that covers part of the dorsal fin and distinctive markings on its skin.

Although it was first discovered back in 2001, it has taken this long for the fish to be officially classified.

The discovery and subsequent classification means there are now five known species of arapaima.

The most recent species was found where the Brazilian Solimoes and Purus rivers join.
Source:
www.globalpost.com

Source

http://worldtruth.tv/