A Chinook salmon in lower Battle Creek was found to be 51 inches long, which could have weighed more than 88 pounds, according to standard size-to-weight ratios. Normally, salmon weigh between 20 and 30 pounds. This gigantic salmon was found during a standard fall salmon survey by some DFG biologists.
This gigantic freshwater Stingray weighed in at over 256kg. A team of fishermen fought hard to reel this guy in, after fishing up other stingrays of varied weight, from different parts of a Thai river. It took them 90 minutes to wrangle this beast out of the water, to be finally brought to the side of the boat. This guy was crowned the largest freshwater fish to ever be caught on rod and line.
This Grizzly bear sized catfish measures in at nearly 9 feet long. This might just be the largest freshwater fish ever on record.
Thai villagers tried to keep the giant catfish alive, but despite great efforts, it died and was eaten by the villagers. This species of catfish is listed as “critacally endangered” by the IUCN (World Conservative Union). This catfish specimen was caught in the Chiang Khong district, and is the biggest one caught since 1981. Due to the nature of this rare catch, the World Wildlife Fund is teaming up with the National Geographic Society to study the planet earth’s largest freshwater fish.
The Cutting Edge, 16 March 2010.
Researchers at the Monterey Bay Aquarium Research Institute have solved the half-century-old mystery of a fish with tubular eyes and a transparent head. Ever since the “barreleye” fish Macropinna microstoma was first described in 1939, marine biologists have known that its tubular eyes are very good at collecting light. However, the eyes were believed to be fixed in place and seemed to provide only a “tunnel-vision” view of whatever was directly above the fish’s head.
A new paper by Bruce Robison and Kim Reisenbichler shows that these unusual eyes can rotate within a transparent shield that covers the fish’s head. This allows the barreleye to peer up at potential prey or focus forward to see what it is eating.
The barreleye fish, or Macropinna microstoma, has extremely light-sensitive eyes that can rotate within a transparent, fluid-filled shield on its head. The fish’s tubular eyes are capped by bright green lenses. The eyes point upward when the fish is looking for food overhead. They point forward when the fish is feeding. The two spots above the fish’s mouth are olfactory organs called nares, which are analogous to human nostrils.
Deep-sea fish have adapted to their pitch-black environment in a variety of amazing ways. Several species of deep-water fishes in the family Opisthoproctidae are called “barreleyes” because their eyes are tubular in shape. Barreleyes typically live near the depth where sunlight from the surface fades to complete blackness. They use their ultra-sensitive tubular eyes to search for the faint silhouettes of prey overhead.
Although such tubular eyes are very good at collecting light, they have a very narrow field of view. Furthermore, until now, most marine biologists believed that barreleye’s eyes were fixed in their heads, which would allow them to only look upward. This would make it impossible for the fishes to see what was directly in front of them, and very difficult for them to capture prey with their small, pointed mouths.
Robison and Reisenbichler used video from MBARI’s remotely operated vehicles (ROVs) to study barreleyes in the deep waters just offshore of Central California.
At depths of 600 to 800 meters (2,000 to 2,600 feet) below the surface, the ROV cameras typically showed these fish hanging motionless in the water, their eyes glowing a vivid green in the ROV’s bright lights. The ROV video also revealed a previously undescribed feature of these fish–its eyes are surrounded by a transparent, fluid-filled shield that covers the top of the fish’s head.
Most existing descriptions and illustrations of this fish do not show its fluid-filled shield, probably because this fragile structure was destroyed when the fish were brought up from the deep in nets. However, Robison and Reisenbichler were extremely fortunate–they were able to bring a net-caught barreleye to the surface alive, where it survived for several hours in a ship-board aquarium. Within this controlled environment, the researchers were able to confirm what they had seen in the ROV video–the fish rotated its tubular eyes as it turned its body from a horizontal to a vertical position.
This face-on view of a barreleye shows its transparent shield lit up by the lights of MBARI’s remotely operated vehicle Tiburon. As in the other photos, the two spots above the fish’s mouth are are olfactory organs called nares, which are analogous to human nostrils.
In addition to their amazing “headgear,” barreleyes have a variety of other interesting adaptations to deep-sea life. Their large, flat fins allow them to remain nearly motionless in the water, and to maneuver very precisely (much like MBARI’s ROVs). Their small mouths suggest that they can be very precise and selective in capturing small prey. On the other hand, their digestive systems are very large, which suggests that they can eat a variety of small drifting animals as well as jellies. In fact, the stomachs of the two net-caught fish contained fragments of jellies.
After documenting and studying the barreleye’s unique adaptations, Robison and Reisenbichler developed a working hypothesis about how this animal makes a living. Most of the time, the fish hangs motionless in the water, with its body in a horizontal position and its eyes looking upward. The green pigments in its eyes may filter out sunlight coming directly from the sea surface, helping the barreleye spot the bioluminescent glow of jellies or other animals directly overhead. When it spots prey (such as a drifting jelly), the fish rotates its eyes forward and swims upward, in feeding mode.
Barreleyes share their deep-sea environment with many different types of jellies. Some of the most common are siphonophores (colonial jellies) in the genus Apolemia. These siphonophores grow to over 10 meters (33 feet) long. Like living drift nets, they trail thousands of stinging tentacles, which capture copepods and other small animals. The researchers speculate that barreleyes may maneuver carefully among the siphonophore’s tentacles, picking off the captured organisms.
The barreleye fish’s eyes rotate to help the fish keep its “eyes on the prize,” while its transparent shield protects the fish’s eyes from the siphonophore’s stinging cells. MBARI researchers speculate that Macropinna microstoma may eat animals that have been captured in the tentacles of jellies, such as this siphonophore in the genus Apolemia. The “head” of the siphonophore (at right) pulls the animal through the water, its stinging tentacles streaming out like a living drift net.
Robison and Reisenbichler hope to do further research to find out if their discoveries about Macropinna microstoma also apply to other deep-sea fish with tubular eyes. The bizarre physiological adaptations of the barreleyes have puzzled oceanographers for generations. It is only with the advent of modern underwater robots that scientists have been able to observe such animals in their native environment, and thus to fully understand how these physical adaptations help them survive.
source: http://www.thecuttingedgenews.com/index.php?article=11185&pageid=28&pagename=Sci-Tech
The aquarium is a part of the Ocean Expo Commemorative National Government Park located in Motobu, Okinawa. The aquarium is made up of four-floors which hold attractions of deep sea creatures, sharks, coral, tropical fish and other fish tank decor. The aquarium is set on 19,000 m² of land, holds a total of 77 tanks with 10,000 m³ of water. Water for the saltwater exhibits is pumped into the aquarium from 350m offshore 24 hours a day.
The main tank called the ‘Kuroshio Sea’ holds 7,500-cubic meters (1,981,290 gallons) of water and features the world’s second largest acrylic glass panel, measuring 8.2 meters by 22.5 meters with a thickness of 60 centimeters. Whale sharks and manta rays are kept amongst many other fish species in the main tank.
On 16 June 2007 at 10:25 PM a manta ray was born at the aquarium after a gestation of 374 days.
The aquarium holds 80 species of coral and is one of very few that keep whale sharks in captivity, and is currently trying to breed them.
TAKE A TOUR INSIDE THE WORLD’S LARGEST AQUARIUM IN THE WORLD IN ATLANTA – GEORGIA AQUARIUM
http://www.georgiaaquarium.org/
