archer fish

Goby fish, found in tropical waters, have a gills and a breathing system that allows them o draw air form the air and the water. The can walk on land and swim.

Some people install fish tanks filled with expensive “fengu shui fish” such as arowana or “red dragon” fish can help escape disasters and get rich. Once, $175,000 was paid for an albino arowana fish, believed in Asia to bring good luck.

Archer fish of the Indo-Austroasiatic region shoot jets of water to capture prey. Some have been observed knocking down insects four feet away. Archerfish reach lengths of 20 centimeters. They have large eyes and excellent eyesight. They are one of the few species of fish that is proficient at looking above the surface of water. When it takes aim at an insect it compensates for the way light bends when it passes from the air through the water.

Archerfish have an upward-pointing mouth. The shoot jets of water droplets at their prey, knocking it of their leave, branch or grass perches into the water where they are eaten. The fish shoots the water by pressing its against a long grove that runs along the roof of its mouth and jerks its gill covers together, forcing a stream of water out like water in a water pistol. It may fire two or three times before getting the range right. Even so it gets its prey a high percentage of the time.

Archerfish in Java have been observed shooting a stream of water 10½ feet. Channeled by a groove between the fish's tongue and the roof of its mouth the water is propelled by the contraction of its gills. Crickets and ants, common victims, are often blasted off their perch into the water where they are gobbled up by the fish. If the blast doesn't knock them down outright the weight of the water is often enough to force them into the water. [Source: Return of Java's Wildlife" by Dater and Mary Plage, June 1985]

Mekong Giant Catfish

The Mekong giant catfish (Pangasianodon gigas) it is the world’s largest catfish fish and a candidate for the world’s largest freshwater fish. Reaching three meters (10 feet) in length and weighing almost 650 pounds (295 kilograms), its lives mainly in the lower half of the Mekong River system, in Cambodia, Laos, Thailand, and Vietnam.

According to National Geographic: Mekong giant catfish have very low-set eyes and are silvery to dark gray on top and whitish to yellow on the bottom. They are toothless herbivores who live off the plants and algae in the river. Juveniles wear the characteristic catfish “whiskers,” called barbels, but these features shrink as they age. Average life span in the wild: More than 60 years. [Source: National Geographic website]

Mekong giant catfish

“Highly migratory creatures, giant catfish require large stretches of river for their seasonal journeys and specific environmental conditions in their spawning and breeding areas. They are thought to rear primarily in Cambodia’s Tonle Sap lake and migrate hundreds of miles north to spawning grounds in Thailand. Dams and human encroachment, however, have severely disrupted their lifecycle. [Ibid]

Eleanor J. Sterling and Merry D. Camhi wrote in Natural History magazine, The Mekong giant catfish, is just one of the region’s struggling, overfished residents. With such grand proportions, a jackpot of succulent flesh that once sold at a premium to urban restaurants, the giant catfish was a fisherman’s prize catch. In the mid-twentieth century, hundreds of giant catfish---a naturally rare species---were caught each year, but recently the annual catch has declined to fewer than ten. Overfishing is the main cause of the decline, but habitat fragmentation and alteration of spawning grounds by dams and navigation projects also contribute. Today, the giant catfish is critically endangered, its range is greatly restricted, and the average size of individuals is declining. In recent years, Cambodia, Laos, and Thailand have outlawed catching the giant catfish. But the species is migratory, so a regional agreement may be necessary to prevent its demise. [Source: Eleanor J. Sterling and Merry D. Camhi, Natural History magazine, December 2007]

Giant Freshwater Stingrays

The giant freshwater stingray is a species of stingray native to large rivers and estuaries of Southeast Asia. It is one of the largest freshwater fishes in the world, with reports from the Chao Phraya and Mekong Rivers of individuals weighing 500 to 600 kilograms (1,100 to 1,300 pounds). Its numbers are dwindling due to overfishing and habitat loss, and it is in danger of extinction. The smaller freshwater whipray of New Guinea and northern Australia was once considered to be conspecific with the giant freshwater stingray but is now recognised as a separate species. [Source: Wikipedia]

Freshwater giant stingrays are among the largest of the approximately 200 species of rays. They can be found in a handful of rivers in Southeast Asia and northern Australia. The giant freshwater stingray was originally described from Thailand (where it occurs in the Chao Phraya, Nan, Mekong, Bangpakong, Prachinburi and Tapi Rivers). The giant freshwater stingray is also found in Indonesia (the Mahakam River Basin in Kalimantan) and Malaysia (the Kinabatangan River in Sabah). There are also records from various other river systems in the region. It is not clear whether all these fish are a single species or are subspecies or are a species complex. Dr Terry Bertozi, of the Evolutionary Biology Unit of the South Australian Museum in Adelaide, Australia, and is collecting genetic samples to determine whether these are the same species of stingray found in the rivers of Northern Australia.

World's Smallest Fish Found in Indonesia

Giant freshwater stingray

In January 2005, AP reported: “Scientists have discovered the world's smallest fish on record in an acidic peat swamp in Indonesia, with a see-through body and a head that is unprotected by a skeleton, researchers said. Mature females of the Paedocypris progenetica, a member of the carp family, only grow to 7.9 millimeters (0.31 inches) and the males have enlarged pelvic fins and exceptionally large muscles that may be used to grasp the females during copulation, researchers wrote in the Proceedings of the Royal Society. [Source: Michael Casey, AP, January 25, 2005]

"This is one of the strangest fish that I've seen in my whole career,' said Ralf Britz, zoologist at the Natural History Museum in London, who helped analyze the fish's skeleton. "It's tiny, it lives in acid and it has these bizarre grasping fins. I hope we'll have time to find out more about them before their habitat disappears completely." The previous record for small size, according to the Natural History Museum in London, was held by an 8-millimeter species of Indo-Pacific goby.

The new fish was discovered on Sumatra island by fish experts Maurice Kottelat from Switzerland and Tan Heok Hui from the Raffles Museum of Biodiversity Research in Singapore. They were working with colleagues from Indonesia and with Kai-Erik Witte from the Max Planck Institute in Germany. "You don't wake up in the morning and think today we will find the smallest fish in the world," Kottelat told The Associated Press. He said the record of finding the world's smallest fish was not important, preferring to focus on what he said was "scientifically significant." "What's important is finding a complete vertebrae in a body so small," he said.

Kottelat said he first came across the fish in 1996, but originally misidentified it as a member of an already existing species. "But then we realized this one was different." According to the researchers, the fish live in dark, tea-colored water with an acidity of ph 3, at least 100 times more acidic than rainwater. Swamps like this were once thought to harbor very few animals, but recent research has revealed that they are highly diverse and home to many species that occur nowhere else. Peat swamps are under threat in Indonesia from fires lit by plantation owners and farmers as well as unchecked development and farming. Several populations of Paedocypris have already been lost, researchers say, according to the Natural History Museum.


Northern snakeheads are a species of fish native to East Asia. Some species can stand upright and wriggle for short distances across land. In Asia it is regarded as a good eating fish. In North American no one thought much of the fish until it showed up in the Potomac River in Washington D.C. along with reports that it viscously ate other fish and multiplied quickly and walk across land and infest other waterways.

Helen Fields wrote in Smithsonian magazine: The voracious "Frankenfish" has turned up in the Potomac River, Lake Michigan and a California lake, sparking fears of an ecological Armageddon. But is the Asian import a monster or the victim of monster hype? The northern snakehead is native to Asia and is one of 29 snakehead species. It made its national news debut in 2002, after an angler at a pond behind a strip mall in Crofton, Maryland, caught a long, skinny fish, about 18 inches from end to end, that neither he nor his fishing buddy recognized. [Source: Helen Fields, Smithsonian magazine, February 2005]

It was after another angler caught a snakehead in the same pond and netted some babies that all hell broke loose. National newspaper and TV news reports described snakeheads as vicious predators that would eat every fish in a pond, then waddle across land to another body of water and clean it out. A reporter from the Baltimore Sun called it “a companion for the Creature from the Black Lagoon.” The scariest reports, fortunately, turned out to be mistaken. While some species of snakeheads can indeed wriggle long distances across the ground, the northern snakehead — the only species found in the Crofton pond — appears not to be one of them. But northern snakeheads do like to eat other fish, and a heavy rain could conceivably wash one or more from the pond into a nearby river that runs through a National Wildlife Refuge and into the Chesapeake Bay, the largest estuary in North America. To eliminate the snakehead menace, Maryland wildlife officials dumped the pesticide rotenone into the Crofton pond, killing all of its fish. Six adult snakeheads went belly up — as did more than 1,000 juveniles. Problem solved. Or so it appeared. Two years later, northern snakeheads fulfilled biologists — worst fear and showed up in the Potomac River.

Besides Crofton and the Potomac, the fish have popped up in several other places in the United States. In 1997, one was caught in a Southern California lake. A couple more appeared in Florida waters in 2000. In Massachusetts, one was caught in 2001 and a second in 2004. And in July 2004, an angler caught two in a lake in a Philadelphia park. Like the Crofton fish, the Philadelphia ones had settled in and started reproducing. But unlike the Crofton fish, they had access to a river — the Schuylkill, which feeds into the Delaware.

The northern snakehead, which is native to parts of China, far eastern Russia and the Korean peninsula, may seem plug-ugly to the undiscerning eye — it has big, pointy teeth and, given its particularly heavy mucus covering, a slime problem. It can grow up to five feet long. Like its reptilian namesake, it’s long and slender and can sport blotchy snakelike patterns on its skin. Unlike most fish, the northern snakehead has little sacs above its gills that function almost like lungs; the fish can surface and suck air into the sacs, then draw oxygen from the stored air as it swims. The air sacs are handy for surviving in waters that are low in oxygen, and even allow the fish to survive out of water for a couple of days, as long as it doesn’t dry out. A female lays thousands of eggs at a time, and both parents guard their offspring in a large nest they make in a clearing of aquatic plants.

Northern snakeheads are a popular food in their native range; they’re said to be good eating, particularly in watercress soup, if a bit bony. They’re fished commercially and raised in fish farms in Asia.” But after they started showing up in American waterways “the U.S. Fish and Wildlife Service soon banned the importation and interstate transport of snakehead. But the bans haven’t stopped everyone. A Los Angeles grocer was arrested for allegedly smuggling live northern snakeheads into the country from Korea and selling them in his store; he pleaded guilty to importing an injurious species. U.S. fans of snakehead soup and other delicacies, however, may still legally obtain killed, frozen snakeheads, which are available in many of the Asian markets that once sold them live. Some fisherman are happy about the arrival of snakeheads and say their a great sporting fish and are challenging and fun to catch.

A snakehead cousin — the bulleye from India and Pakistan — is established in a canal system in Florida. In the mid 2000s it was still possible to import Asian swamp eel, another species that was causing havoc in Florida. In the late 1960sm the walking catfish, another species, showed up in he wild. Great alarm was raised about it but in the end it didn’t cause major damage.

The red-eared slider turtle, a species native to the Mississippi basin, is found across Asia and southern Europe. It was original shipped out of the United States as pet and food source, and is now now consuming native frogs, mollusks and even birds in its adopted lands, and driving away native turtles by out competing them.

northern snakehead

Asian Carp

Asian carp — fish originally from Asia that can grow to four feet (1.2 meters) long and 100 pounds (45 kilograms) and are known for leaping out of the water when boats are near — have taken over the Mississippi River in the United States. They were imported by Southern fish farms but escaped into the Mississippi in large numbers during flooding in the 1990s and have been making their way northward ever since.

In a October 2010 New Yorker article entitled “Fish Out of Water” Ian Frazier wrote about the invasion of Asian carp into the waters of the upper Midwest, a problem that has serious environmental implications. The silver carp, which is originally from China and eastern Siberia, is known for its proclivity to leap out of the water, sometimes rocketing fifteen feet into the air. “Not only are the newcomers upsetting the balance in Midwestern ecosystems; they are knocking boaters’ glasses off and breaking their noses and chipping their teeth and leaving body bruises in the shape of fish,” Frazier wrote. [Source: Ian Frazier, The New Yorker, October 17, 2010]

The carp are highly efficient feeders, and “the fear is that when they get in a lake or a river you will soon have nothing else.” Among the rivers infested by the Asian carp, the Illinois has it worst, with eight thousand silver carp or more per river mile, an infestation that became serious just in the past seven years. Matt O’Hara, a fish biologist, told The New Yorker that during a recent fish survey so many fish jumped out of the water at one point that a camera filming from the nearby shore was unable to see the boat. “Given what they do to an ecosystem, I can’t say I see any advantage at all with these fish, definitely not if they get in the lakes,” O’Hara says.

The governor of Illinois recently announced an agreement to sell local carp to the Chinese; Beijing Zhouchen Animal Husbandry Company has agreed to buy thirty million pounds (and possibly more) by the end of 2011. Mike Houston works for Big River Fish Corporation, the company that is harvesting, packaging, and shipping the carp to China. Houston told the The New Yorker, “People say it’s difficult to find Asian carp in China because they’re all fished out. I like to think, sellin’ silver carp and bighead carp to the Chinese, that we’re sendin’ their own product back to “em. And I’ll tell you, even with all the fish we move, we ain’t makin’ a dent in the Asian carp that’s out there.”

David M. Lodge, a professor of biology at the University of Notre Dame, told the The New Yorker, “I know you can’t not laugh when you see the silver carp jumping all over the place,” but the situation is “tragic” and “people are wrong to trivialize it.” Lodge says that a big issue is how we as a country protect ourselves against invasive species. “At the moment, we are not very good at preventing invasions. We’re constantly reacting after it’s too late.”

Asian Carp Advance on the Great Lakes

There are worries now that the Asian carp will invade the Great Lakes, which are connected to the Mississippi by a complex, 250-mile (402-kilometer) network of rivers and canals engineered more than a century ago. Tens of millions of tons of goods are moved annually along the shipping canals or through the locks that lead into Lake Michigan. An electrical barrier, installed in 2002 to repel fish with a non-lethal jolt, has long been the only thing standing between the carp and Lake Michigan, the gateway to the four other lakes. [Source: Caryn Rousseau and John Flesher, Associated Press, December 2, 2009]

In April 2011, Andrew Stern of Reuters wrote: Asian carp are hardier than scientists previously thought, with the invasive species capable of surviving in the Great Lakes by bottom-feeding, U.S. officials said. The voracious and prolific Bighead and Silver carp are considered a dire threat to the lakes' $7 billion fisheries, sucking up plankton and crowding out other species. The carp have surged up the Mississippi River system within 25 miles (40 kilometres) of three electrified barriers erected in a Chicago-area canal to block their progress. [Source: Andrew Stern, Reuters, April 28, 2011

Last year, scientists initially concluded there was not enough plankton to sustain carp in Lake Michigan. But they recently learned Silver carp will eat Cladophora, a plentiful algae that thrives on fertilizer runoff, while Bighead carp can survive on detritus on the lake bottom."Initially we thought this was a wasteland" for carp due to the lack of plankton, said Leon Carl of the U.S. Geological Survey, which is conducting studies on the still-mysterious invaders and ways to stop them.

Several weapons are being investigated to combat carp. Scientists have tested 240 compounds and isolated 10 that could be carp pheromones -- chemicals that would attract carp so they can be harvested or killed. They are also trying to create tiny particles of fish poison that would lodge only in the fine gills of Asian carp. And they are experimenting with powerful "water guns" to deter carp.

A new problem scientists discovered is that carp can spawn on shorter waterways than previously thought, creating the need for more widespread monitoring, Carl said. It is possible carp will eat themselves out of existence, or succumb to over-fishing as happened in their native China. Last week, fishermen gathered up 42 tonnes of carp, and Goss set a target of 1 million tonnes. The catch is mostly shipped to China.


Mudskippers are small four inch long fish which are found in Borneo as well as peninsular Malaysia and other parts of Asia. They can crawl on land and live up to week without water. Mudskippers are found in mudflats that spend a great deal of time out of water. There are the only fish that feed, court and defend their territories on land. Residing in Old World mangrove swamps and muddy estuaries from West Africa to Papua New Guinea and Australia, they spend about half their time on land and can live up to week without water. The largest species reach lengths of about 20 centimeters.

Mudskippers are somewhat similar to the first creatures that moved from the seas to land and evolved into amphibians, reptiles, dinosaurs, mammals and other terrestrial animals. Most species feed on plankton and algae. Some feed on worms, crustaceans and insects and other food and small animals they can extract from the mud.

Mudskippers can breath on both land and in the water. Like all fish they have gills. But what makes them unique are the little chambers they have outside their gills which entrap water and enables them to breath on land, sort of like a scuba tank in reverse. To breath in this way they need to regularly fill their mouths with water. They can also absorb oxygen through their skin like a frog does but to do this they need to keep their skin wet and often roll around in the mud to achieve that end.

Mudskippers have relatively large, funny-looking, protruding bug eyes. These eyes are so well adapted for seeing on land, the ability to see in water is greatly diminished. Below their eyes are small cups that hold water. As their eyes become dehydrated they retreat for a time into the cups, which remoisten them.

There are three main kinds of mudskippers. The smallest ones spend most of their time in the water. They usually hang out at the water's edge sifting for worms and crustaceans. Medium size ones spend their time in the mid-tide areas of swamps. They are solitary, feed almost exclusively on algae and sometimes build mud walls to defend their territory. The third and largest kind hangs out in mudflats close to shore. It is a carnivore and feeds mostly on small crabs.

Mudskipper Movement

Mudskippers move by suddenly flexing the rear parts of their bodies, which cause them to jump or skip, hence their name. Their front pair of pectoral fins helps them stay steady. These also help the animals to walk and have a rigid bone and fleshy base and operate sort of like crutches.

Mudskippers spend most of their time in burrows that can be found in both land and water. During low tide Mudskippers cruise the land looking for food, They like to stay close to their burrow to make a quick escape from predators such as birds, crabs and snakes. During high tides they spend much of their time in their burrows safe from predatory fish. To ensure the don’t suffocate they gulp air and transport it to their burrow so they have enough to breath unto low tide arrives.

Mudskippers come out of the water to feed on insects and other invertebrates that like mud. Under the slightest threat they dart back into their burrows. When the need to move quickly to escape danger or catch prey they curl their tails sideways, flicking them and slide across the mud.

Some mudskippers can climb tree branches and mangrove roots by using their front flippers to grasp a tree's stems and branches. There are other fishes which walk on land, like the walking catfish, but the mudskipper is the only one that climbs trees.

Mudskipper Mating

Mudskippers mate out of water. Because their front fins are used in getting around they perform their courtship displays with the long fins that run down their backs. Normally the back fins of the male lie flat. During the mating season they become erect, sometimes revealing bright colors. Male mudskippers sometimes leap into the air so they can be seen at a distance.

During the mating season males often carve up the available land area into territories and dig burrows with one or several entrances, and sometimes “turrets” and “moats.” To attract mates they do courtship dances. Some species do multiple flips, one after another.

Fierce battles between males occur over the best burrowing spots. Many males puff out their cheeks and gill chambers by filling them with air to lure a female into their burrows. If a male is successful he plugs the entrance with mud and mates. After they are born mudskipper larvae float out of the burrow water into open water. After about 35 days they develop into mudskippers and return to the mud flat and live as an amphibian fish.

Image Sources: Wikimedia Commons, archer fish: Warren Photography; giant catfish and stingray; National Geographic and relive earth

Text Sources: National Geographic, Natural History magazine, Smithsonian magazine, Wikipedia, New York Times, Washington Post, Los Angeles Times, Times of London, The Guardian, Top Secret Animal Attack Files website, The New Yorker, Time, Newsweek, Reuters, AP, AFP, The Economist, BBC, and various books and other publications.

Last updated November 2012

This site contains copyrighted material the use of which has not always been authorized by the copyright owner. Such material is made available in an effort to advance understanding of country or topic discussed in the article. This constitutes 'fair use' of any such copyrighted material as provided for in section 107 of the US Copyright Law. In accordance with Title 17 U.S.C. Section 107, the material on this site is distributed without profit. If you wish to use copyrighted material from this site for purposes of your own that go beyond 'fair use', you must obtain permission from the copyright owner. If you are the copyright owner and would like this content removed from, please contact me.