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Friday Fun: Bird Using Bait to Fish

Posted on May 15, 2009  Comments (9)

In the webcast an Aukuu bird (Black-crowned Night Heron) fishes using bread as bait. They normally hunt by waiting at the side of a lake and fishing. This individual learned how to bait the fish with bread and improve the fishing results. It also passed on that method to other birds that learned how to use the bait method themselves.

Another bird using bait (with turtles trying to get the bait) and another bird using bait (with a stork trying to steal the fish). And another one. The videos seem to be different species of birds to me.

Related: Orangutan Attempts to Hunt Fish with Spear – Dolphins Using Tools to Hunt – Bird Brain experiment – posts on animals

European Eels in Crisis After 95% Decline in Last 25 years

Posted on May 5, 2009  Comments (1)

Eels in crisis after 95% decline in last 25 years

But the action the Environment Agency is about to take is upsetting those who rely on the eel for their livelihoods. A ban on exporting eels out of Europe – they are a popular dish in the far east – is proposed, along with a plan to severely limit the fishing season and the number of people who will be allowed licences.

It seems pretty obvious we have over-fished the oceans. Without effective regulation we will destroy the future of both the wildlife and our food source.

Related: Fishless Future – South Pacific to Stop Bottom-trawling – North American Fish Threatened – Chinook Salmon Vanish Without a Trace

The eel remains one of the world’s most mysterious creatures. It is generally accepted that European eels – Anguilla anguilla – are born in the Sargasso Sea near Bermuda.

As leaf-like larvae, they are swept by the Gulf Stream towards Europe, a journey that may take a year. When the larvae reach the continental shelf they change into “glass eels” and in the spring begin to move through estuaries and into freshwater.

The animals develop pigmentation, at which point they are known as elvers and are similar in shape to the adult eel. Elvers continue to move upstream and again change colour to become brown or yellow eels.

When the fish reach full maturity – some can live to 40 and grow to 1m long – they migrate back to the ocean. Females are reported to carry as many as 10m eggs. They return to the Sargasso Sea, spawn and die.

Macropinna Microstoma: Fish with a Transparent Head

Posted on March 3, 2009  Comments (3)

That is a pretty awesome fish. 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.

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.

Full press release

Related: Ocean Life – Female Sharks Can Reproduce Alone – Octopus Juggling Fellow Aquarium Occupants – Amazing Science: Retroviruses

Friday Fun: Octopus Juggling Fellow Aquarium Occupants

Posted on October 31, 2008  Comments (11)

photo of Otto the Octopus

Otto the octopus wreaks havoc

Otto is constantly craving for attention and always comes up with new stunts so we have realised we will have to keep more careful eye on him – and also perhaps give him a few more toys to play with.

“Once we saw him juggling the hermit crabs in his tank, another time he threw stones against the glass damaging it. And from time to time he completely re-arranges his tank to make it suit his own taste better – much to the distress of his fellow tank inhabitants.”

Staff believe that the octopus called Otto had been annoyed by the bright light shining into his aquarium and had discovered he could extinguish it by climbing onto the rim of his tank and squirting a jet of water in its direction. The short-circuit had baffled electricians as well as staff at the Sea Star Aquarium in Coburg, Germany, who decided to take shifts sleeping on the floor to find out what caused the mysterious blackouts.

Related: more fun posts – The Brine Lake Beneath the Sea – Baby Sand Dollars Clone Themselves When They Sense Danger – Virgin Birth for Another Shark Species

Virgin Birth for Another Shark Species

Posted on October 12, 2008  Comments (1)

Virgin shark birth in Virginia

The first time it happened, scientists thought it might be a fluke. A female hammerhead shark residing at a zoo in Omaha, Neb., had not been in contact with male sharks for at least three years and yet experienced a “virgin birth.” She delivered a single pup.

But it has happened again, according to today’s issue of the Journal of Fish Biology. This time, a blacktip shark… had spent nearly her entire eight years at either the Virginia Aquarium without any male companionship from her kind.

Related: No sex for all-girl fish species – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – posts on the science and life

Asymmetrical Brains Aid Multi-tasking

Posted on September 19, 2008  Comments (0)

Asymmetrical brains help fish (and us) to multi-task:

In the animal world, the ability to multi-task is a matter of life and death. Many species must be ever-watchful for food, while simultaneously looking out for predators who would view them in the same way Like too many open applications that slow down a computer, these multiple tasks compete for the brain’s finite resources. Those who survive life’s challenges are those with an edge at efficiently dealing with multiple demands.

One way of doing this is to use parallel processing – to delegate different parts of a problem to different pieces of hardware. This is exactly the situation found in the human brain, with two asymmetric hemispheres associated with different mental abilities. And this ‘lateralisation’ is not unique to us, but seems to be present in all back-boned animals, from fish to apes. An explanation for this asymmetry now becomes obvious – it may allow animals to multi-task, acting as a sort of cerebral division of labour.
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In these cases, regardless of parallel processing power, an asymmetric brain is clearly a disadvantage. The two scientists believe that the tipping point between these pros and cons comes when an animal has to perform difficult mental tasks.

Other studies have shown that asymmetrical brains endow wild chimpanzees with superior termite-fishing skills, and (equally wild) human children with better mathematical and verbal abilities than their classmates. It may be that over the course of evolution, our brain’s halves started to work together more effectively as they became more different and specialised. It is ironic and sad then, that the opposite seems to hold true for the divergence of human cultures.

Related: The Brain is Wired to Mull Over Decisions – Mapping Where Brains Store Similar Information – The Siren Song of Multitasking – No Sleep, No New Brain Cells

North American Fish Threatened

Posted on September 13, 2008  Comments (1)

North American Fish Under Threat

Nearly 40 percent of fish species in North America are imperiled, according to a new survey by fish experts, the U. S. Geological Survey, and the American Fisheries Society, up 92 percent from the last survey done in 1989.
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No single cause explains the ongoing fish losses, Taylor and others agree. Habitat loss, invasive species, diseases, dams, and water contaminants all contribute.

“Fish are kind of canaries in the coal mine,” said Howard Jelks of the USGS and lead author of the report, published in Fisheries. “If you change the water to something that’s not able to support these fish, it’s also not going to be as high quality for recreating, for eating the fish out of these streams, for drawing water that’s ultimately used for drinking, or for other things.”

Related: Fishless Future – SelFISHing – Chinook Salmon Vanish Without a Trace – Running Out of Fish

Bill Nye the Science Guy, Interview

Posted on September 7, 2008  Comments (2)

Bill Nye the Science Guy Makes Green “Stuff Happen”

One of your first “Stuff Happens” episodes is about breakfast. What’s so special about breakfast and the environment?
Are you kidding? It’s the most important meal of the day. It had the iconic story that North American pigs – from where we get bacon – I presume unwillingly are fed feed made with South American anchovies (and herrings and sardines). Farmers say eating fish helps their animals grow to that wonderfully ample size consumers want. Because of this, we’re accidentally destroying an ecosystem. It’s the story of stories.

How so?
We’re seriously depleting the world’s anchovy population and leaving the penguins and South American seabirds with nothing to eat. These birds are dangerously close to starving because the anchovy and sardine populations have been decimated.

What can we do?
Strange as it may seem, you could eat more anchovies. This would raise the price of the fish and make anchovy fish feed more costly and less desirable to pig farmers. Also eat organic bacon from pigs raised on 100% agricultural feed. If you’re looking for the true organic meat products, make sure it’s grass-fed only.

Related: Pigs Instead of Pesticides – Interview of Steve Wozniak – The Engineer That Made Your Cat a Photographer – Interview with Donald Knuth

Running Out of Fish

Posted on May 11, 2008  Comments (1)

I have posted before about the overfishing problems: Fishless Future – SelFISHing – Chinook Salmon Vanish Without a Trace. Here is an emotional article on the problem – How the world’s oceans are running out of fish

Ninety years of industrial-scale exploitation of fish has, he and most scientists agree, led to ‘ecological meltdown’. Whole biological food chains have been destroyed.
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In 2002, the year an EU report revealed that the Senegalese fish biomass had declined 75 per cent in 15 years, Brussels bought rights for four years’ fishing of tuna and bottom-dwelling fish on the Senegal coasts, for just $4m a year. In 2006, access for 43 giant EU factory fishing vessels to Mauritania’s long coastline was bought for £24.3m a year. It’s estimated that these deals have put 400,000 west African fishermen out of work; some of them now take to the sea only as ferrymen for desperate would-be migrants to the Canary Islands and Europe.
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Protecting up to 40 per cent of the world’s oceans in permanent refuges would enable the recovery of fish stocks and help replenish surrounding fisheries. ‘The cost, according to a 2004 survey, would be between £7bn and £8.2bn a year, after set-up. But put that against the £17.6bn a year we currently spend on harmful subsidies that encourage overfishing.’
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The Newfoundland cod fishery, for 500 years the world’s greatest, was exhausted and closed in 1992, and there’s still no evidence of any return of the fish. Once stocks dip below a certain critical level, the scientists believe, they can never recover because the entire eco-system has changed.

Amazon Molly Fish are All Female

Posted on April 24, 2008  Comments (2)

No sex for all-girl fish species

A fish species, which is all female, has survived for 70,000 years without reproducing sexually, experts believe.
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The species, found in Texas and Mexico, interacts with males of other species to trigger its reproduction process. The offspring are clones of their mother and do not inherit any of the male’s DNA. Typically, when creatures reproduce asexually, harmful changes creep into their genes over many generations.
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One theory is that the fish may occasionally be taking some of the DNA from the males that trigger reproduction, in order to refresh their gene pool.

Dr Laurence Loewe, of the university’s School of Biological Sciences, said: “What we have shown now is that this fish really has something special going on and that some special tricks exist to help this fish survive. “Maybe there is still occasional sex with strangers that keeps the species alive. Future research may give us some answers.”

He added that their findings could also help them understand more about how other creatures operate. “I think one of the interesting things is that we are learning more about how other species might use these tricks as well,” he said. “It might have a more general importance.”

Related: Female Sharks Can Reproduce Alone – Only Dad’s Genes – Bdelloid Rotifers Abandoned Sex 100 Million Years Ago – Sex and the Seahorse – more posts about fish

ASU Science Studio Podcasts

Posted on April 14, 2008  Comments (1)

Science Studio offers podcasts by the Arizona State University School of Life Sciences with professors discussing science; it is another excellent source of science podcasts. Podcasts include:

  • Of Whales, Fish and Men: Managing Marine Reserves – With 90% of the world’s fisheries in a state of collapse, the questions around establishing marine reserves, monitoring, and species/stock recovery take on critical dimensions. But how do decision-makers, stakeholders, and the public formulate effective conservation policies; ones right for their community?
  • Biology on Fire – Regents’ Professor, Mac Arthur Fellow, author and a world’s expert on fire and fire ecology Stephen Pyne talks about how fire, its use, misuse, and its biological nature have shaped our world, before and because of man, and learn how policies of the past still reverberate in our present, in Arizona and globally.
  • Giant Insects: Not just in B movies – Professor Jon Harrison sheds light on the evolution of his scientific career and nature’s biggest order: arthropods. How big is big? In the Paleozoic, cockroaches were the size of housecats and dragonflies the size of raptors.
  • Special Feature: Building a science career – One of the most highly cited ecologists in the world, Jane Lubchenco trod her own unique path to success. In this live recording with the Association for Women in Science, she explains how assertiveness, the art of negotiation, and knowing the currency for promotion and tenure can make the difference between achieving balance between family and career and dropping out the leaky academic pipeline that leads to advancement.

These podcasts are great way to use the internet to serve the mission of universities: to educate. And a great way to promote science.

Related: Lectures from the Stanford Linear Accelerator Center – UC-Berkeley Course Videos – Science Podcast Libraries – Communicating Science to the Public