rhamphotheca:

The American paddlefish, Polyodon spathula
… is a paddlefish living in slow-flowing waters of the Mississippi River drainage system. It appears to have been extirpated from Lake Erie and its tributaries. They are closely related to the sturgeons.
This large Chondrostean freshwater fish may grow to 220 cm (7 feet) and weigh up to 100 kg (220 lbs). The paddlefish takes its common and scientific names from its distinctive snout, which is greatly elongated and flattened into a paddle shape. The American paddlefish is believed to use sensitive electroreceptors on its paddle to detect prey, as well as to navigate while migrating to spawning sites. It feeds primarily on zooplankton but also feeds on crustaceans and bivalves…
(read more: Wikipedia)
illustration by Timothy Knepp, USFWS

rhamphotheca:

The American paddlefish, Polyodon spathula

… is a paddlefish living in slow-flowing waters of the Mississippi River drainage system. It appears to have been extirpated from Lake Erie and its tributaries. They are closely related to the sturgeons.

This large Chondrostean freshwater fish may grow to 220 cm (7 feet) and weigh up to 100 kg (220 lbs). The paddlefish takes its common and scientific names from its distinctive snout, which is greatly elongated and flattened into a paddle shape. The American paddlefish is believed to use sensitive electroreceptors on its paddle to detect prey, as well as to navigate while migrating to spawning sites. It feeds primarily on zooplankton but also feeds on crustaceans and bivalves

(read more: Wikipedia)

illustration by Timothy Knepp, USFWS

rhamphotheca:

The Devils Hole pupfish (Cyprinodon diabolis) is an icon of the conservation movement,” says Darrick Weissenfluh, a U.S. Fish and Wildlife Service biologist who is leading an effort to save the exceedingly rare and endangered fish at a facility within Nevada’s Ash Meadows National Wildlife Refuge. 
Read more:  http://go.usa.gov/KTC5
Photo credit: Olin Feuerbacher
(via: USFWS National Wildlife Refuge System)

rhamphotheca:

The Devils Hole pupfish (Cyprinodon diabolis) is an icon of the conservation movement,” says Darrick Weissenfluh, a U.S. Fish and Wildlife Service biologist who is leading an effort to save the exceedingly rare and endangered fish at a facility within Nevada’s Ash Meadows National Wildlife Refuge.

Read more: http://go.usa.gov/KTC5

Photo credit: Olin Feuerbacher

(via: USFWS National Wildlife Refuge System)

Waterfall Climbing Cave Fish (Cryptotora thamicola)
Also known as the cave angel fish, this species has only been found in subterranean caves within the Pang Mapha karst system in Thailand. The fish has been observed climbing up a small waterfall, using its fins to grasp the rock and resist being swept away by the fast moving waters. Having evolved in darkness, the species has lost body pigmentation and its eyes.
© Chulabus Khatancharoen via Flickr

Waterfall Climbing Cave Fish (Cryptotora thamicola)

Also known as the cave angel fish, this species has only been found in subterranean caves within the Pang Mapha karst system in Thailand. The fish has been observed climbing up a small waterfall, using its fins to grasp the rock and resist being swept away by the fast moving waters. Having evolved in darkness, the species has lost body pigmentation and its eyes.

© Chulabus Khatancharoen via Flickr

Amazon Molly - An All Female Species
Similar to the Amazon Warriors from Greek mythology, the Amazon molly (Poecilia formosa) is a species of fish that is considered to be all female.
Although the females must mate with a male from another species (as sperm is needed to induce embryo growth), the male’s genetic material is not incorporated into the diploid eggs of the mother. As a result, the offspring are clones of the mother.
The species most likely arose from the hybridisation of two other species of molly. The asexual nature of its reproduction benefits the fish in that it has essentially twice the reproductive output in each brood of offspring (as twice as many breeding females are produced compared to a half male half female brood).
Image © President and Fellows of Harvard College

Amazon Molly - An All Female Species

Similar to the Amazon Warriors from Greek mythology, the Amazon molly (Poecilia formosa) is a species of fish that is considered to be all female.

Although the females must mate with a male from another species (as sperm is needed to induce embryo growth), the male’s genetic material is not incorporated into the diploid eggs of the mother. As a result, the offspring are clones of the mother.

The species most likely arose from the hybridisation of two other species of molly. The asexual nature of its reproduction benefits the fish in that it has essentially twice the reproductive output in each brood of offspring (as twice as many breeding females are produced compared to a half male half female brood).

Image © President and Fellows of Harvard College

Arowana (Sceleropages sp.)
Arowanas are a family of freshwater bony fish native to South America, South East Asia and Australia. They are popular in the aquarium trade, especially in Asian countries, due to their resemblance to the oriental dragon. Selective breeding has resulted in varieties with a range of colours and patterns. The fish is associated with wealth and perfect specimens can often fetch a high price; up to several thousand dollars.
Amrn86 on Flickr

Arowana (Sceleropages sp.)

Arowanas are a family of freshwater bony fish native to South America, South East Asia and Australia. They are popular in the aquarium trade, especially in Asian countries, due to their resemblance to the oriental dragon. Selective breeding has resulted in varieties with a range of colours and patterns. The fish is associated with wealth and perfect specimens can often fetch a high price; up to several thousand dollars.

Amrn86 on Flickr

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