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 Newly discovered bacteria-binding protein in the intestine
08.12.2016 | University of Gothenburg

nachricht The balancing act: An enzyme that links endocytosis to membrane recycling
07.12.2016 | National Centre for Biological Sciences

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

Decoding cement's shape promises greener concrete

08.12.2016 | Materials Sciences

Will Earth still exist 5 billion years from now?

08.12.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>