Oscar (Astronotus ocellatus)

The oscar is a species of freshwater cichlid native to the Amazon River basin in South America. The fish grows up to 45 cm (18 in) and is popular in the aquarium trade. Several morphological variations, such as albino and long finned varieties have arisen due to selective ornamental breeding.

Jón Helgi Jónsson on wikimedia commons, Daniella Vereeken on Flickr

danidoroi:

Chicago goes to war with Asian carp
By Pallab Ghosh

The US city of Chicago is considering drastic measures to prevent giant fish infesting North America’s Great Lakes.
Authorities are thinking of blocking the city’s canal system to stop Asian carp entering Lake Michigan.
Such a move could cost up to $18bn (£11bn) and cause huge economic disruption to the city.
Cheaper options are also being examined, including making burgers out of the fish and eating them to extinction.
This species of carp, as the name suggests, is native to the Far East.
They were originally introduced to southern US states more than three decades ago to control algal build-up in sewage treatment plants. But they escaped into the Mississippi River and proliferated, making their way north towards the Great Lakes.
More than a metre in length, they have displaced indigenous fish species along the way.
More

danidoroi:

Chicago goes to war with Asian carp

The US city of Chicago is considering drastic measures to prevent giant fish infesting North America’s Great Lakes.

Authorities are thinking of blocking the city’s canal system to stop Asian carp entering Lake Michigan.

Such a move could cost up to $18bn (£11bn) and cause huge economic disruption to the city.

Cheaper options are also being examined, including making burgers out of the fish and eating them to extinction.

This species of carp, as the name suggests, is native to the Far East.

They were originally introduced to southern US states more than three decades ago to control algal build-up in sewage treatment plants. But they escaped into the Mississippi River and proliferated, making their way north towards the Great Lakes.

More than a metre in length, they have displaced indigenous fish species along the way.

More

Kissing Gourami (Helostoma temminckii)

Kissing gouramis are well known for locking their lips in what appears to be a romantic display of affection. However, this behaviour is actually a fight.

Males will often challenge each other to a fight of dominance by pressing their lips together and pushing the other fish back. The lips of the kissing gourami are lined with horny teeth that are otherwise used for scraping plant matter off surfaces.

While the fighting itself is rarely harmful, repeated harassment from an aggressive fish may cause death due to stress.

Justin K on Flickr, Green Yoshi on Wikimedia Commons

Redtail Catfish (Phractocephalus hemioliopterus)

The redtail catfish is a large species of freshwater catfish native to South America. Despite growing to 1.8m in length, juveniles are common in the aquarium trade. Due to its large size, it is considered a game fish by anglers.

Wikipeixes, Clinton & Charles Robertson

Desert Pupfish (Cyprinodon macularius)

The desert pupfish is an endangered species of freshwater fish native to the desert springs and streams of the United States and Mexico. Due to its harsh environment, it is able to tolerate extreme conditions.

The fish is able to survive temperatures from 4ºC to 45ºC (40ºF to 113ºF) and a salinity up to 70 parts per thousand (seawater is approximately 35 ppt). They can also live in extremely lowly oxygenated waters.

The fish have been noted to be more abundant in areas with high vegetation cover, pH and salinity, and low oxygen. This suggests that it takes advantage of the extreme conditions that other fish are unable to live in.

© 2012 Andrew Borcher, P.V. Loiselle

kqedscience:

The Oregon Chub Is The First Fish Ever Taken Off The Endangered Species List
“A tiny minnow that lives only in Oregon backwaters is the first fish ever taken off U.S. Endangered Species Act protection because it is no longer threatened with extinction.
The U.S. Fish and Wildlife Service was to announce Tuesday that the Oregon chub was recovered, 21 years after it went on the endangered species list. The agency will monitor the fish for nine years to make sure populations continue to grow.
"We’re not saying it won’t need management," said Paul Henson, Oregon director of Fish and Wildlife. "But they can leave the hospital and get out to be an outpatient."
Read more from The Associated Press: http://goo.gl/IZmTr9

kqedscience:

The Oregon Chub Is The First Fish Ever Taken Off The Endangered Species List

A tiny minnow that lives only in Oregon backwaters is the first fish ever taken off U.S. Endangered Species Act protection because it is no longer threatened with extinction.

The U.S. Fish and Wildlife Service was to announce Tuesday that the Oregon chub was recovered, 21 years after it went on the endangered species list. The agency will monitor the fish for nine years to make sure populations continue to grow.

"We’re not saying it won’t need management," said Paul Henson, Oregon director of Fish and Wildlife. "But they can leave the hospital and get out to be an outpatient."

Read more from The Associated Press: http://goo.gl/IZmTr9

Rummy Nose Tetra (Hemigrammus sp.)
The rummy nose tetra is the name given to three very similar looking freshwater fish native the Amazon Basin. It’s common name comes from the red blush across its face. In the wild, the fish inhabits very soft, acidic water. In an aquarium setting, breeding in hard water leads to sterility in the offspring.
Mukyo via Flickr

Rummy Nose Tetra (Hemigrammus sp.)

The rummy nose tetra is the name given to three very similar looking freshwater fish native the Amazon Basin. It’s common name comes from the red blush across its face. In the wild, the fish inhabits very soft, acidic water. In an aquarium setting, breeding in hard water leads to sterility in the offspring.

Mukyo via Flickr