Please select your home edition
Edition
Absolute Marine

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.
GAC Pindar Sailing NewsMake Fast MooringsAbsolute Marine

Related Articles

Introducing the Airbnb of the mooring and marina world
Have you ever struggled to find an available mooring, or do you have a mooring that is sitting vacant? Have you ever struggled to find an available mooring, or do you have a mooring that is sitting vacant? makefastmooring.com is aiming to solve this problem by connecting boat owners with those with vacant moorings or berths. With a growing number of moorings and marinas in New Zealand, Australia and around the world, makefastmooring.com allows people to find, rent and share moorings and berths.
Posted today at 11:07 am
Introducing the Airbnb of the mooring and marina world
Have you ever struggled to find an available mooring, or do you have a mooring that is sitting vacant? Have you ever struggled to find an available mooring, or do you have a mooring that is sitting vacant? makefastmooring.com is aiming to solve this problem by connecting boat owners with those with vacant moorings or berths. With a growing number of moorings and marinas in New Zealand, Australia and around the world, makefastmooring.com allows people to find, rent and share moorings and berths.
Posted today at 11:07 am
Tasmanian fishing
Offshore, tuna are still around and Bluefin seem to be about in even greater numbers than years past. Coffee coloured freshwater still seems to be the norm around the state’s coastline, making angling difficult for those who have salt in their veins. Offshore, tuna are still around and Bluefin seem to be about in even greater numbers than years past. A charter operator from the South of the state notched up his 1,000th tuna caught recently, so that’s not a bad record for the season.
Posted on 6 Dec
More bass stocking for Gippsland anglers
Freshwater fishing opportunities for recreational anglers in Gippsland are set to improve further Freshwater fishing opportunities for recreational anglers in Gippsland are set to improve further following the release of 122,000 Australian bass fingerlings last week.
Posted on 6 Dec
OceanLED adds a new underwater light to the sport series
OceanLED, the global leader in marine LED lighting, introduced new Sport S3124s as the latest addition to Sport series. OceanLED, the global leader in marine LED lighting, today introduced its new Sport S3124s as the latest addition to the Sport series. Engineered specifically for sport fishing and active cruising, the advanced underwater LED Sport S3124s light packs a powerful 3,000 fixture lumens punch in a stylish dual Ultra White and Midnight Blue light option.
Posted on 1 Dec
Seven dead, one missing, three rescued in Kaipara fishing accident
Searchers have recovered seven bodies from the Kaipara Harbour, after a fishing boat got into trouble today. Searchers have recovered seven bodies from the Kaipara Harbour, northwest of Auckland, after a fishing boat got into trouble on Saturday. As of Sunday two of the three people listed as missing on Saturday have been found dead, and their bodies recovered. Three were rescued and were in hospital, police said.
Posted on 26 Nov
Verado re-power 'astonishing'
Josh Ker wasn’t prepared for what happened when he recently re-powered Bertram 25 flybridge with a 350hp Mercury Verado Josh Ker, the man who heads up Bigfish Gear in Darwin, has been involved in offshore fishing for the past 25 years but he still wasn’t prepared for what happened when he recently re-powered his Bertram 25 flybridge with a 350hp Mercury Verado.
Posted on 24 Nov
Murray Cod seized out of season
A quick call from a concerned member of the public to the 13FISH line yesterday has seen four people from Cobram caught A quick call from a concerned member of the public to the 13FISH line yesterday has seen four people from Cobram caught with undersize Murray Cod during the closed season.
Posted on 23 Nov
New listing – 2005 Black Watch 40
Many upgrades including new generator, winch, Furuno TZ touchscreen, antifoul/prop-speed etc. This vessel represents excellent value. Many upgrades including new generator, winch, Furuno TZ touchscreen, antifoul/prop-speed etc.
Posted on 22 Nov
If you fish recreationally, don’t sell your catch
Two fishers from Burnside have been arrested for selling fish they caught using a recreational licence. Two fishers from Burnside have been arrested for selling fish they caught using a recreational licence. Fisheries officers believe the Golden Perch were caught at Lake Eildon.
Posted on 21 Nov