Grayling

[Anderoo]

I am always one to appreciate and respect others opinions but I do have to mention that if you use sweetcorn for grayling please do not feed very much as grayling in particular find it difficult to digest. That said it does seem to sort out the bigger fish and especially on a pacey river can be presented well due to it's weight and density over that of maggots.

 

I have read this before on another forum - is it definitely true? Any idea why? And how much would be too much?

[Kappa]

I have read this before on another forum - is it definitely true? Any idea why? And how much would be too much?

 

I find it hard to believe they would have trouble with corn when they eat stones:

 

http://www3.interscience.wiley.com/journal...=1&SRETRY=0

 

Rich

[Dick Dastardly]

I am always one to appreciate and respect others opinions but I do have to mention that if you use sweetcorn for grayling please do not feed very much as grayling in particular find it difficult to digest.

 

 

Whats this based on then?

[Guest bbamboo]

Just a question but why would grayling be any different to other course fish in this matter.

[Worms]

Just a question but why would grayling be any different to other course fish in this matter.

Because they aren't coarse fish

 

They're salmon family, hence the adipose fin. I've always found it odd that grayling take sweetcorn but I assume they mistake it for fish eggs which they are quite partial to.

 

If they do have digestive problems with sweetcorn then it is not too surprising as the salmon family are well known for their meat eating habits!

[Guest bbamboo]

[Dick Dastardly]

Because they aren't coarse fish

 

They're salmon family,

 

Still not sure why this is though same guts as any other fish.

[DavyR]

I don't know about grayling, but I find sweetcorn impossible to digest...

[Worms]

Still not sure why this is though same guts as any other fish.

All variations on a theme, anyway. Most predatory fish have stomachs most herbivorous fish do not.

 

None of my literature gave very good descriptions of fish digestive systems (enzyme-wise) but I found this fascinating site. It's obviously a study for more research. Interestingly enough no mention of the breakdown of cellulose (plant cell walls) is made. This is something that Humans are incapable of as well (hence Davy R's observations ). Most animals rely on microscopic "gut flora" to do that job including some turtles and lizards so maybe fish as well?

http://www.carp-pike-and-conger-eels.co.uk/enzymes.htm

Carbohydrases have perhaps excited the most interest of all the enzymes, particularly because salmonids do not handle the large carbohydrate molecules very well, and many workers wanted to determine the reason. Further, because there are several carbohydrases, the possibility that different enzyme combinations might show adaptations to different diets also intrigued some investigators. Also, herbivorous fish might be expected to have more carbohydrase activity and less tryptic activity than carnivores or omnivores.

 

Just found this on Grass Carp http://www.springerlink.com/content/7t731v6n636mv101/

 

I'm guessing that this is lacking in salmonids!

 

Getting there!

http://afsjournals.org/doi/abs/10.1577/154...AR%3E2.0.CO%3B2

 

and page 62 of this tome.

http://books.google.co.uk/books?id=lBltoKD...ish&f=false

Edited November 19, 2009 by Worms

[Chris Plumb]

I first asked this question on here in 2002. And struggled then to find any evidence that sweetcorn was harmful to grayling. I can accept that they may not be able to digest sweetcorn husks in the same way that we can't - but can't grayling get rid of them the same way we do???

 

Might make a good little PhD project for someone!

 

 

C.