Please select your home edition
Edition
Bakewell-White Yacht Design

Missing link of how fishes triumphed over toxic oceans revealed

by ARC Centre of Excellence on 19 Jun 2013
How fish won the oxygen war Jodie Rummer
An international team of scientists have revealed a missing link in the story of how the fishes triumphed over toxic oceans and past climate changes.

The key to the evolutionary success of fish – and their possible survival in future – may lie with a molecule that they ultimately bequeathed to humans: hemoglobin, the precious carrier of oxygen into our brain, heart, muscles and other organs.

In a paper in the latest edition of the journal Science, Dr Jodie Rummer of the ARC Centre of Excellence for Coral Reef Studies and colleagues from the University of British Columbia report a groundbreaking discovery about how fish manage to survive in hostile water conditions.

'Four hundred million years ago the oceans were not what they are today. They were low in oxygen, high in CO2 and acidic,' says Dr Rummer. 'Yet the fishes not only survived in these unpromising circumstances, they managed to thrive. Their secret weapon was a system for unloading huge amounts of oxygen from the hemoglobin in their blood, whenever the going got really tough.

'Hemoglobin in the blood takes up oxygen in the gills of fish and the lungs of humans. It then carries it round the body to the heart, muscles and organs until it encounters tissues that are highly active and producing a lot of CO2.' 'The acid is a signal to the hemoglobin to unload as much of its oxygen as possible into the tissues,' she explains.

'These early fish managed to develop a way to maximize the delivery of oxygen, even when the water they lived in was low in it. They had a phenomenal capacity for releasing oxygen just when needed: it was one of the big secrets of their evolutionary success, to the extent they now make up half the vertebrates on the planet.'

The fishes’ oxygen release system became even more efficient over the ensuing 150-270 million years, when it was necessary to deliver large amounts to organs such as the eye – which requires very large O2 loads to function well and avoid vision cell death – and which was essential to seeing clearly under water, to hunt or avoid predators.

The researchers made their discovery by deciphering the biochemistry of how rainbow trout manage to rapidly double oxygen release in certain tissues, when they swim in waters that cause them stress.

The fish system is many times more efficient than the one inherited by humans (as our amphibian ancestors branched away from higher fishes around 350-400my ago when the hemoglobin system was still in its early stages of development), but its discovery may lead to new ways of understanding and tackling conditions influenced by oxygen levels in the body.

'Also, we feel that if we can understand how fish coped with low-oxygen, high CO2, acidic waters in the past, it will give us some insight into how they might cope with man-made climate change which appears to be giving rise to such conditions again,' Dr Rummer says.
Barz Optics - Melanin LensesEnsign 660Kiwi Yachting - Lewmar

Related Articles

A slithery ocean mystery
One sentence in a New York Times article caught Larry Pratt’s eye and set the scientific investigation in motion. One sentence in a New York Times article caught Larry Pratt’s eye and set the scientific investigation in motion. The story was about fishermen harvesting juvenile eels in coastal waters of the Gulf of Maine and selling them for more than $2,500 a pound, mostly for unagi in Asian fish markets.
Posted today at 12:13 am
A slithery ocean mystery
One sentence in a New York Times article caught Larry Pratt’s eye and set the scientific investigation in motion. One sentence in a New York Times article caught Larry Pratt’s eye and set the scientific investigation in motion. The story was about fishermen harvesting juvenile eels in coastal waters of the Gulf of Maine and selling them for more than $2,500 a pound, mostly for unagi in Asian fish markets.
Posted today at 12:13 am
New fishing season is a mere 30 days away
Time to start visualising the zing of a reel and bend of a rod, as the little hints of spring and summer start appearing Reports from around the regions (we would say this, of course) hint at some great fishing to be had, as the days lengthen and temperatures slowly rise!
Posted on 29 Aug
More net free fishing at Gippsland River Mouths
Migratory fish in Gippsland Lakes will have more protection at river mouths when exclusion areas for commercial netting Migratory fish in the Gippsland Lakes will have more protection at river mouths when exclusion areas for commercial netting are expanded by 50 per cent under new arrangements to be introduced next year by the Andrews Labor Government.
Posted on 26 Aug
Stacer’s Ocean Rangers are now tougher than ever
The new 589 Ocean Ranger now features more freeboard at 730mm, bringing the model in line with the rest of the range. Due to customer demand Stacer has released two new models in their plate range to now include the 589 and 619 Ocean Ranger Hard Tops offering a more budget friendly option that is still packed with power and strength.
Posted on 17 Aug
Shark 'trophy' hunters land in hot water
Two young men who removed the jaws of a dead Great White Shark have found themselves in trouble with the law. Two young men who removed the jaws of a dead Great White Shark have found themselves in trouble with the law.
Posted on 16 Aug
Port Phillip Bay Fishers gather to celebrate Bay fishing
Jaala Pulford welcomed key fishing industry representatives and recreational anglers to Port Phillip Bay Conference Minister for Agriculture, Jaala Pulford today welcomed key fishing industry representatives and recreational anglers to the first Port Phillip Bay Conference in Altona.
Posted on 13 Aug
Trout opening festival expands to include Ballarat
To welcome opening of trout fishing season Goulburn Fishing Festival will be joined by a similar event at Ballarat To welcome the opening of the 2016 trout fishing season in rivers the popular Goulburn Fishing Festival will be joined by a similar family-friendly event at Ballarat this year on Saturday 3 September.
Posted on 12 Aug
TowBoatUS Ocean City removes harmful fishing nets
Earlier this summer, three miles of open water was all that separated two efforts to protect and nurture marine life Earlier this summer, three miles of open water was all that separated two efforts to protect and nurture marine life on the Atlantic Coast.
Posted on 12 Aug
Mansfield trout conference a must for anglers
Recreational anglers can learn about Victoria’s wild trout fisheries at a free one day conference on Saturday 5 November Recreational anglers can learn more about Victoria’s wild trout fisheries at a free one day conference on Saturday 5 November at Mansfield.
Posted on 10 Aug