Zander madness

[cookiesdaughtersdad]

Zander have physoclistous swim bladder ie no duct to gut. Instead a gas gland. It’s dead easyto get things wrong. I’ve just done an on line learning course on ecology. Now I should be very familiar with all this yet I got two out of the ten questions at the end wrong. Very frustrating.

I had a little google ,Nev and copied this for a quick read

"In more derived varieties of fish (the physoclisti) the connection to the digestive tract is lost. In early life stages, these fish must rise to the surface to fill up their swim bladders; in later stages, the pneumatic duct disappears, and the gas gland has to introduce gas (usually oxygen) to the bladder to increase its volume and thus increase buoyancy. This process begins with the acidification of the blood in the rete mirabile when the gas gland excretes lactic acid and produces carbon dioxide, the latter of which acidifies the blood via the bicarbonate buffer system. The resulting acidity causes the hemoglobin of the blood to lose its oxygen (Root effect) which then diffuses partly into the swim bladder. Before returning to the body, the blood re-enters the rete mirabile, and as a result, virtually all the excess carbon dioxide and oxygen produced in the gas gland diffuses back to the arteries supplying the gas gland via a countercurrent multiplication loop. Thus a very high gas pressure of oxygen can be obtained, which can even account for the presence of gas in the swim bladders of deep sea fish like the eel, requiring a pressure of hundreds of bars.[5] Elsewhere, at a similar structure known as the 'oval window', the bladder is in contact with blood and the oxygen can diffuse back out again. Together with oxygen, other gases are salted out[clarification needed] in the swim bladder which accounts for the high pressures of other gases as well.[6]"

It came from this just one of lots out there!

https://en.wikipedia.org/wiki/Swim_bladder

So its easy to see why an extended fight in water that has low DO (dissolved oxygen) which will increase the likehood of lactic acid and carbon dioxide being produced, can cause problems.

Cheers, Alan

[davelumb]

I had a little google...

It's fleece was white as snow, and every where that Google went,
Googlesdaughtersdad was sure to go.

[cookiesdaughtersdad]

I had a little google...

It's fleece was white as snow, and every where that Google went,
Googlesdaughtersdad was sure to go.

Now that Mr Lumb is funny!

[davelumb]

I had a little google...

It's fleece was white as snow, and every where that Google went,
Googlesdaughtersdad was sure to go.

Now that Mr Lumb is funny!

[Steve Le maitre]

I had a little google...

It's fleece was white as snow, and every where that Google went,
Googlesdaughtersdad was sure to go.

Yer we can all google, next he'll be googling 'a conscience' , that combined with all this new found knowledge there will be nothing left but to give up on this fishing lark.

[cookiesdaughtersdad]

I had a little google...

It's fleece was white as snow, and every where that Google went,
Googlesdaughtersdad was sure to go.

Yer we can all google, next he'll be googling 'a conscience' , that combined with all this new found knowledge there will be nothing left but to give up on this fishing lark.

Googling 'a conscience' wot you on about? and the fact is this newly found knowledge is several years old now.
How knowledge is gained is irrelevant

Cheers, Alan

[Donky123]

The process of gasses entering or exiting the gass bladder on a physoclistous (ie non ducted) fish can take hours if not days. It’s unlikely that high lactic acid causes via stress of capture has a great effect.

Barotrauma from the expansion of gasses is a different matter

[cookiesdaughtersdad]

The process of gasses entering or exiting the gass bladder on a physoclistous (ie non ducted) fish can take hours if not days. It’s unlikely that high lactic acid causes via stress of capture has a great effect.

Barotrauma from the expansion of gasses is a different matter

That would surprise me ,Donkey as it would be quite limiting for these more evolved fish species moving up and down the water columns, can you point me in the directing of something I can read on this particular part of the subject please?

Zander can struggle with buoyancy after being caught from water just a few feet deep so barotrauma is not a factor in these cases. Other species such as barbel also struggle because of the effects of lactic acid (different cause I know!) and you can often tell when they are ready, as a few tiny bubbles come out of there mouths after been passed through the pneumatic duct.

Cheers, Alan

[Stewlaws]

I was on an 'Atlantic Salmon Trust' discussion with an eminent Scientist with 17 years worth of studies heading a discussion, the person I went with a pedant on information and did not understand the answer to a question, she asked 3 times for an analogy of the answer in context to that given, (she persisted on 3 attempts of an explanation that made sense to her) this guy upon the last explanation finally admitted that the data they had was incomplete and it was a 'plausible answer though unsubstantiated' ...... Never have I seen a leading light pulled apart by a lady who was vehement in the fact that as a scientific lead for this study, he should be working on facts not supposition, this thread takes me straight back to 2011 in a classroom at Fordingbridge Hampshire.

Don't believe all you hear and never be afraid to challenge something about doesn't sit right, on whatever side of the fence!

[Neville Fickling]

Zander have physoclistous swim bladder ie no duct to gut. Instead a gas gland. It’s dead easyto get things wrong. I’ve just done an on line learning course on ecology. Now I should be very familiar with all this yet I got two out of the ten questions at the end wrong. Very frustrating.

I had a little google ,Nev and copied this for a quick read

"In more derived varieties of fish (the physoclisti) the connection to the digestive tract is lost. In early life stages, these fish must rise to the surface to fill up their swim bladders; in later stages, the pneumatic duct disappears, and the gas gland has to introduce gas (usually oxygen) to the bladder to increase its volume and thus increase buoyancy. This process begins with the acidification of the blood in the rete mirabile when the gas gland excretes lactic acid and produces carbon dioxide, the latter of which acidifies the blood via the bicarbonate buffer system. The resulting acidity causes the hemoglobin of the blood to lose its oxygen (Root effect) which then diffuses partly into the swim bladder. Before returning to the body, the blood re-enters the rete mirabile, and as a result, virtually all the excess carbon dioxide and oxygen produced in the gas gland diffuses back to the arteries supplying the gas gland via a countercurrent multiplication loop. Thus a very high gas pressure of oxygen can be obtained, which can even account for the presence of gas in the swim bladders of deep sea fish like the eel, requiring a pressure of hundreds of bars.[5] Elsewhere, at a similar structure known as the 'oval window', the bladder is in contact with blood and the oxygen can diffuse back out again. Together with oxygen, other gases are salted out[clarification needed] in the swim bladder which accounts for the high pressures of other gases as well.[6]"

It came from this just one of lots out there!

https://en.wikipedia.org/wiki/Swim_bladder

So its easy to see why an extended fight in water that has low DO (dissolved oxygen) which will increase the likehood of lactic acid and carbon dioxide being produced, can cause problems.

Cheers, Alan

That is very interesting but the lactic acid has nothing to do with over exercise it’s a means to obtain Oxygen to fill the bladder. Bit of inorganic chemistry there!!!Interesting just the same . though. Lactic acid and muscle exercise is a different matter.

[Steve Le maitre]

I had a little google...

It's fleece was white as snow, and every where that Google went,
Googlesdaughtersdad was sure to go.

Yer we can all google, next he'll be googling 'a conscience' , that combined with all this new found knowledge there will be nothing left but to give up on this fishing lark.

Googling 'a conscience' wot you on about? and the fact is this newly found knowledge is several years old now.
How knowledge is gained is irrelevant

Cheers, Alan

Alan you can't worry about people fishing. You're never going to stop those that purposely go out and target fish in 90'

[cookiesdaughtersdad]

Zander have physoclistous swim bladder ie no duct to gut. Instead a gas gland. It’s dead easyto get things wrong. I’ve just done an on line learning course on ecology. Now I should be very familiar with all this yet I got two out of the ten questions at the end wrong. Very frustrating.

I had a little google ,Nev and copied this for a quick read

"In more derived varieties of fish (the physoclisti) the connection to the digestive tract is lost. In early life stages, these fish must rise to the surface to fill up their swim bladders; in later stages, the pneumatic duct disappears, and the gas gland has to introduce gas (usually oxygen) to the bladder to increase its volume and thus increase buoyancy. This process begins with the acidification of the blood in the rete mirabile when the gas gland excretes lactic acid and produces carbon dioxide, the latter of which acidifies the blood via the bicarbonate buffer system. The resulting acidity causes the hemoglobin of the blood to lose its oxygen (Root effect) which then diffuses partly into the swim bladder. Before returning to the body, the blood re-enters the rete mirabile, and as a result, virtually all the excess carbon dioxide and oxygen produced in the gas gland diffuses back to the arteries supplying the gas gland via a countercurrent multiplication loop. Thus a very high gas pressure of oxygen can be obtained, which can even account for the presence of gas in the swim bladders of deep sea fish like the eel, requiring a pressure of hundreds of bars.[5] Elsewhere, at a similar structure known as the 'oval window', the bladder is in contact with blood and the oxygen can diffuse back out again. Together with oxygen, other gases are salted out[clarification needed] in the swim bladder which accounts for the high pressures of other gases as well.[6]"

It came from this just one of lots out there!

https://en.wikipedia.org/wiki/Swim_bladder

So its easy to see why an extended fight in water that has low DO (dissolved oxygen) which will increase the likehood of lactic acid and carbon dioxide being produced, can cause problems.

Cheers, Alan

That is very interesting but the lactic acid has nothing to do with over exercise it’s a means to obtain Oxygen to fill the bladder. Bit of inorganic chemistry there!!!Interesting just the same . though. Lactic acid and muscle exercise is a different matter.

My thinking is that if both chemicals, lactic acid and carbon dioxide are being produced my the muscles and into the bloodstream through the extreme exercise of the fight, then the same blood chemistry has been produced that enables the fish to increase the gasses in the swim bladder. What levels are produced in the fight and what levels are required in the swim bladder I dont know, but the production will happen quicker in warm water with low DOs, it just a theory buy I believe its a very logical one based on some over lapping science.

Cheers, Alan

Cheers, Alan

[cookiesdaughtersdad]

I had a little google...

It's fleece was white as snow, and every where that Google went,
Googlesdaughtersdad was sure to go.

Yer we can all google, next he'll be googling 'a conscience' , that combined with all this new found knowledge there will be nothing left but to give up on this fishing lark.

Googling 'a conscience' wot you on about? and the fact is this newly found knowledge is several years old now.
How knowledge is gained is irrelevant

Cheers, Alan

Alan you can't worry about people fishing. You're never going to stop those that purposely go out and target fish in 90'

Steve, I dont worry about things I cant change but I am interested in the physiology of the fish and for no other reason than being interested.

Cheers, Alan

[Mark Phillips]

AW doesn't want the predators but simply cant get rid of them and so earn good money allowing anglers to fish for them and hopefully cull a few at the same time.
In my experience of snorkelling the thermocline can be rather close to the surface and as Nev just wrote there is very little wind at the moment so mixing should be minimal.
I think Zander are more suited to warm conditions than pike but catching one on light gear (which a lot of these guys do) from deep cool water only to release it in warm shallow water isnt the best way to treat your quarry.

Cheers, Alan

Of course AW want the predators, what on earth are you on about. Not with standing they do actually understand the importance of their presence, but they also make good money from the predator fishing, after all, they don't have to re-stock them like the trout and certainly don't want to see them culled. AW actively promote the predator fishing, something a lot of us wish they didn't, but hey... thankfully there's still plenty of us who keep stum.

As to catching zander in warm water - they fight harder in warm water and they die, just like the pike. Sadly I know that from my early days of zander fishing, when we'd fish the fens on the summer nights and be propping fish up with bank sticks to hopefully help them recover. I stopped doing that pretty quickly. A handful of anglers fishing through this heat wave is expected, you'll always get that - but allowing competitions with 72 anglers... all they had to do was postpone. It's the same bunch of guys who fish all these competitions, most of them Polish and the wannabe brigade, and we all know how much some of them care about fish welfare over holding up a trophy on Facebook to lap up the glory

Mark, AW actively removed predators for years, they couldn't eradicate them and so have simple cashed in on what they cant get rid of. They never cared of about the importance having predators, just the troot.
I think the main reason zander are delicate in warm weather is that they actively use lactic acid to contol their buoyancy, the excess lactic acid produced in the fight causes them to loose control of their buoyancy and its the subsequent stress that kills them.

Cheers, Alan

Cheers Alan, but yes I know that - I actually caught some Grafham pike from a Cambs gravel pit, they lost weight rather quickly as well... but you're talking about 30 or more years ago - attitudes have long since changed, due to a lot of hard work by certain individuals and yeah, OK, more by luck than judgement they're now a good source of income - especially now the Polish and their bum buddies have been having these competitions. As far as having predators in their resis... I worked for AW and met a few of the fishery managers in my time there, trust me, they get it.

On your second point, you've lost me there. Pretty sure swim bladders don't work like that. I'm sure someone on here knows their onions on that score.

Oh and for anyone who's had a cheeky look at the groups Facebook page and managed not to throw up after reading all the baloney, fish are still being laid across the boards to measure them I suppose rule breaking is a lot easier at night

I suppose my opinion on AW is a bit outdated, Mark but what is still true is that they put money over the welfare of predatory fishes.

Re the swim or gas bladders, I am quite sure thats how they work on many species including zander. What it enables them to do is not having a reliance on returning to the surface and also gives some of them like the freshwater eel, the ability to create very high pressures within the bladder for deep waters.

Cheers, Alan

You're 100% right about that Alan, the predator fishing and especially the competitions are all good revenue streams for them. I also don't think they care about the impact on the fish and longer term on the fishing itself. A few people now commenting in social media that there were a load of dead and dying zander on Rutland shortly after the Polish zander night fishing competition held during the recent heat wave. Event should have been cancelled and re-scheduled by a couple of weeks, now it has started to cool down.

[Will Smith]

It is not just the Zander that suffer, I adjudicated at a completion on Rutland some years ago, Perch were lying belly up all over the place, some good fish amongst them as well, all with their swim bladders poking out of their mouths, competitors were bringing them up from the depths as quickly as possible unhooking and recording them and then throwing them back in as quickly as possible.
Never again for me or my pals who also volunteered, competitions and predators are two words that should never by used in the same sentence IMO, when money or glory is involved fish welfare goes straight out of the window.

Will.

[davelumb]

It is not just the Zander that suffer, I adjudicated at a completion on Rutland some years ago, Perch were lying belly up all over the place, some good fish amongst them as well, all with their swim bladders poking out of their mouths, competitors were bringing them up from the depths as quickly as possible unhooking and recording them and then throwing them back in as quickly as possible.
Never again for me or my pals who also volunteered, competitions and predators are two words that should never by used in the same sentence IMO, when money or glory is involved fish welfare goes straight out of the window.

Will.

Shocking.

[fergie68]

The trout competitions up here were a disgrace I remember them on Loch Awe poly bags full of wild brown trout killed just to be weighed it wasnt unusual for them then just to be dumped bizarrely the escapee rainbow trout in the Loch didn't count.
Some of these Clowns were among the worst of the head shakers ie they'd look at your trolling set up and walk away shaking their heads . Pricks

[Steve Le maitre]

The trout competitions up here were a disgrace I remember them on Loch Awe poly bags full of wild brown trout killed just to be weighed it wasnt unusual for them then just to be dumped bizarrely the escapee rainbow trout in the Loch didn't count.
Some of these Clowns were among the worst of the head shakers ie they'd look at your trolling set up and walk away shaking their heads . Pricks

People should always look at a trolling setup and walk away shaking their heads

[Neville Fickling]

AW doesn't want the predators but simply cant get rid of them and so earn good money allowing anglers to fish for them and hopefully cull a few at the same time.
In my experience of snorkelling the thermocline can be rather close to the surface and as Nev just wrote there is very little wind at the moment so mixing should be minimal.
I think Zander are more suited to warm conditions than pike but catching one on light gear (which a lot of these guys do) from deep cool water only to release it in warm shallow water isnt the best way to treat your quarry.

Cheers, Alan

Of course AW want the predators, what on earth are you on about. Not with standing they do actually understand the importance of their presence, but they also make good money from the predator fishing, after all, they don't have to re-stock them like the trout and certainly don't want to see them culled. AW actively promote the predator fishing, something a lot of us wish they didn't, but hey... thankfully there's still plenty of us who keep stum.

As to catching zander in warm water - they fight harder in warm water and they die, just like the pike. Sadly I know that from my early days of zander fishing, when we'd fish the fens on the summer nights and be propping fish up with bank sticks to hopefully help them recover. I stopped doing that pretty quickly. A handful of anglers fishing through this heat wave is expected, you'll always get that - but allowing competitions with 72 anglers... all they had to do was postpone. It's the same bunch of guys who fish all these competitions, most of them Polish and the wannabe brigade, and we all know how much some of them care about fish welfare over holding up a trophy on Facebook to lap up the glory

Mark, AW actively removed predators for years, they couldn't eradicate them and so have simple cashed in on what they cant get rid of. They never cared of about the importance having predators, just the troot.
I think the main reason zander are delicate in warm weather is that they actively use lactic acid to contol their buoyancy, the excess lactic acid produced in the fight causes them to loose control of their buoyancy and its the subsequent stress that kills them.

Cheers, Alan

Cheers Alan, but yes I know that - I actually caught some Grafham pike from a Cambs gravel pit, they lost weight rather quickly as well... but you're talking about 30 or more years ago - attitudes have long since changed, due to a lot of hard work by certain individuals and yeah, OK, more by luck than judgement they're now a good source of income - especially now the Polish and their bum buddies have been having these competitions. As far as having predators in their resis... I worked for AW and met a few of the fishery managers in my time there, trust me, they get it.

On your second point, you've lost me there. Pretty sure swim bladders don't work like that. I'm sure someone on here knows their onions on that score.

Oh and for anyone who's had a cheeky look at the groups Facebook page and managed not to throw up after reading all the baloney, fish are still being laid across the boards to measure them I suppose rule breaking is a lot easier at night

I suppose my opinion on AW is a bit outdated, Mark but what is still true is that they put money over the welfare of predatory fishes.

Re the swim or gas bladders, I am quite sure thats how they work on many species including zander. What it enables them to do is not having a reliance on returning to the surface and also gives some of them like the freshwater eel, the ability to create very high pressures within the bladder for deep waters.

Cheers, Alan

You're 100% right about that Alan, the predator fishing and especially the competitions are all good revenue streams for them. I also don't think they care about the impact on the fish and longer term on the fishing itself. A few people now commenting in social media that there were a load of dead and dying zander on Rutland shortly after the Polish zander night fishing competition held during the recent heat wave. Event should have been cancelled and re-scheduled by a couple of weeks, now it has started to cool down.

Need photographs to build a case Mark

[Mark Phillips]

AW doesn't want the predators but simply cant get rid of them and so earn good money allowing anglers to fish for them and hopefully cull a few at the same time.
In my experience of snorkelling the thermocline can be rather close to the surface and as Nev just wrote there is very little wind at the moment so mixing should be minimal.
I think Zander are more suited to warm conditions than pike but catching one on light gear (which a lot of these guys do) from deep cool water only to release it in warm shallow water isnt the best way to treat your quarry.

Cheers, Alan

Of course AW want the predators, what on earth are you on about. Not with standing they do actually understand the importance of their presence, but they also make good money from the predator fishing, after all, they don't have to re-stock them like the trout and certainly don't want to see them culled. AW actively promote the predator fishing, something a lot of us wish they didn't, but hey... thankfully there's still plenty of us who keep stum.

As to catching zander in warm water - they fight harder in warm water and they die, just like the pike. Sadly I know that from my early days of zander fishing, when we'd fish the fens on the summer nights and be propping fish up with bank sticks to hopefully help them recover. I stopped doing that pretty quickly. A handful of anglers fishing through this heat wave is expected, you'll always get that - but allowing competitions with 72 anglers... all they had to do was postpone. It's the same bunch of guys who fish all these competitions, most of them Polish and the wannabe brigade, and we all know how much some of them care about fish welfare over holding up a trophy on Facebook to lap up the glory

Mark, AW actively removed predators for years, they couldn't eradicate them and so have simple cashed in on what they cant get rid of. They never cared of about the importance having predators, just the troot.
I think the main reason zander are delicate in warm weather is that they actively use lactic acid to contol their buoyancy, the excess lactic acid produced in the fight causes them to loose control of their buoyancy and its the subsequent stress that kills them.

Cheers, Alan

Cheers Alan, but yes I know that - I actually caught some Grafham pike from a Cambs gravel pit, they lost weight rather quickly as well... but you're talking about 30 or more years ago - attitudes have long since changed, due to a lot of hard work by certain individuals and yeah, OK, more by luck than judgement they're now a good source of income - especially now the Polish and their bum buddies have been having these competitions. As far as having predators in their resis... I worked for AW and met a few of the fishery managers in my time there, trust me, they get it.

On your second point, you've lost me there. Pretty sure swim bladders don't work like that. I'm sure someone on here knows their onions on that score.

Oh and for anyone who's had a cheeky look at the groups Facebook page and managed not to throw up after reading all the baloney, fish are still being laid across the boards to measure them I suppose rule breaking is a lot easier at night

I suppose my opinion on AW is a bit outdated, Mark but what is still true is that they put money over the welfare of predatory fishes.

Re the swim or gas bladders, I am quite sure thats how they work on many species including zander. What it enables them to do is not having a reliance on returning to the surface and also gives some of them like the freshwater eel, the ability to create very high pressures within the bladder for deep waters.

Cheers, Alan

You're 100% right about that Alan, the predator fishing and especially the competitions are all good revenue streams for them. I also don't think they care about the impact on the fish and longer term on the fishing itself. A few people now commenting in social media that there were a load of dead and dying zander on Rutland shortly after the Polish zander night fishing competition held during the recent heat wave. Event should have been cancelled and re-scheduled by a couple of weeks, now it has started to cool down.

Need photographs to build a case Mark

I've come across a number of comments both from other anglers and on social media claiming to have seen dead fish after these competitions, but yes, people need to post pictures for them to be credible. I'm not trying to build a case, just highlighting what some would rather was swept under the carpet. I'm not sure AW management would even act if the proof was handed to them. I'm not against these things per se, but they seem intent on holding them in the warmer months and/or to the detriment of the regular punters - a good example being the pike maniacs, which was held prior to the water opening to the paying public, thus guaranteeing p**s easy fishing for the Poles and bolloxing the fishing for everyone else. Oh and every year there's more and more of these events taking place, to the point where it's proving harder and harder to book a boat where there's been sufficient time elapsed to avoid sloppy seconds.

[fergie68]

The trout competitions up here were a disgrace I remember them on Loch Awe poly bags full of wild brown trout killed just to be weighed it wasnt unusual for them then just to be dumped bizarrely the escapee rainbow trout in the Loch didn't count.
Some of these Clowns were among the worst of the head shakers ie they'd look at your trolling set up and walk away shaking their heads . Pricks

People should always look at a trolling setup and walk away shaking their heads

Or its not done properly

[Stewlaws]

I've Tench fished a water that held some Ok pike (Mid 20's) until word was banded around and these were targeted relentlessly, now there is an explosion of small lean 1-2lb pike that plague the silver fishing by constantly snatching any roach or rudd on your line.

Any water that fails to protect an Apex species is neglecting their riparian management... Fortunately for some of these waters, they appear to get away with the constant pressure.

[Neville Fickling]

I don’t think anyone will struggle to get a boat at the moment.

[stubbojo]

silly question maybe ....why cant the comps run oct, nov, or later for that matter ......

and i have not googled anything ......i just go on my own experiences over the years of observation.....and practices rightly or wrongly

steve