Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Rare albino ratfish has eerie, silvery sheen

26.09.2007
A ghostly, mutant ratfish caught off Whidbey Island in Washington state is the only completely albino fish ever seen by both the curator of the University of Washington's 7.2 million-specimen fish collection and a fish and wildlife biologist with more than 20 years of sampling fish in Puget Sound.

"Ratfish usually hang out in places with soft, muddy bottoms," says Jon Reum, the aquatic and fishery sciences doctoral student who found the albino ratfish during a UW research project. "The typical ratfish in Puget Sound is brown or black with a smattering of white spots so it blends in with the sediments."

This fish was almost pure white with a crystalline layer near the surface of its skin that gave it a silvery sheen.

"It must have been like a beacon," says Ted Pietsch, UW professor of fisheries and aquatic sciences and curator of the UW fish collection. "Why didn't it get eaten, long before this, by some predator, for example, by a spiny dogfish so common in Puget Sound and that love to devour ratfish""

... more about:
»Predator »Puget »Researchers »Reum »Sound »albino

The foot-long female may have been 2 or 3 years old, Reum and Pietsch estimate, making her a teenager in the ratfish world.

She was caught this summer in about 200 feet of water during a UW research project examining the food web in Hood Canal and Puget Sound. Puget Sound is the nation's second-largest estuary in the Lower 48 after Chesapeake Bay. The city of Seattle, home to about 4 million people, is built on its shores. Puget Sound connects to the Pacific Ocean via the Strait of Juan de Fuca to the north.

Albinos, found among mammals, fishes, birds, reptiles and amphibians, have a gene mutation that keeps them from making the pigment melanin. The condition is rare in sea life, Pietsch says. He could find only a handful of sightings of albino sharks, and none of albino ratfish, though ratfish are common and abundant in many places around the world. Puget Sound, for example, is filled with a greater number of ratfish, by far, than any other fish, Reum says. In the June survey that turned up the albino specimen, researchers counted 7,100 ratfish compared to 2,300 English sole, the second most prevalent fish in that sampling.

"I've seen tens of thousands, if not hundreds of thousands, of ratfish in my career, and have not seen a completely albino one before," says Wayne Palsson, a Washington Department of Fish and Wildlife biologist who studies groundfish populations in Puget Sound. "I've seen lightly colored or partially albino ratfish but never completely albino." Palsson says the only other pure albino marine organism of any kind that he's seen in Puget Sound was a sea cucumber collected near UW's Friday Harbor Laboratories in the '90s.

Ratfish are probably so-called because they have tails that are exceptionally long and streamer-like. To move through the water they flap large, wing-like pectoral fins on their sides

There are 33 species around the world, but only one is found in Puget Sound, the white-spotted ratfish. They can grow as long as 3 feet. Like sharks and rays, ratfish have skeletons composed of cartilage instead of bone.

After the albino ratfish was caught the researchers attempted to keep her alive in a bucket of water but, in spite of boards placed over the top, she managed to flip out of the bucket onto the deck during the night. She is now preserved and part of the UW Fish Collection, which has 82 other ratfish specimens, ranging from eggs to full-grown adults. The collection, which focuses on North Pacific and Bering Sea fishes, is needed by researchers on and off campus to identify species and to understand fish biology and conservation.

Pietsch says ratfish seek meals of sea-bottom worms, crabs and clams by burrowing their snub snouts into the mud and using special sensors in their heads to detect the faint electrical signals given off whenever animals use their muscles.

Powerful jaws and grinding teeth able to crack the shells of crabs and clams require caution by researchers and fishermen who handle them. Ratfish don't bite divers or swimmers in the water, Reum says, but they get snappish when brought on board.

And then there's that venomous spine.

Located on their back, just in front of the dorsal fin, ratfish have a spine several inches long that is serrated on one edge, needle sharp at the tip and delivers an irritating venom. The spine could be the reason the only predators to eat Puget Sound ratfish are dogfish and six-gill sharks, both able to gulp ratfish down whole and headfirst, Reum and Pietsch say.

The Hood Canal food-web survey, funded by the National Oceanic and Atmospheric Administration and the Hood Canal Dissolved Oxygen Program, is led by UW assistant professor Tim Essington. He also has SeaDoc Society funding to examine another aspect of the Puget Sound food web using historical trawl records to create a database of fish abundance over time. It seeks to find, for instance, whether ratfish have always been so numerous or whether changes in their main predators allowed them to flourish.

As far as humans eating ratfish, Reum says New Zealand is the only place he knows where there is a commercial fishery. They're used for fish and chips.

Has Reum ever tasted ratfish" A spasm of dismay briefly crosses his face at the thought. Then he laughs.

"We're always challenging each other during our expeditions to eat one, but, they're just a really greasy fish. And they really stink. Their stomach contents and juices are particularly foul."

Sandra Hines | EurekAlert!
Further information:
http://www.washington.edu

Further reports about: Predator Puget Researchers Reum Sound albino

More articles from Life Sciences:

nachricht What the world's tiniest 'monster truck' reveals
23.08.2017 | American Chemical Society

nachricht Treating arthritis with algae
23.08.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>