Crayfish pools....Eels!

[Anderoo]

Some very interesting points there Mark. Crays have certainly had a big influence on the sizes of perch and chub on the Thames, Cherwell and Ouse (and other rivers - but these are the ones I mostly fish).

 

I know nothing about big eel fishing but (despite all the jokes!) I do have a great deal of respect for those who put in all that effort into catching them.

[Dick Dastardly]

Yes very interesting,thanks for that Mark. Im really looking forward to this years eeling.

[Phone]

All,

 

Let me show my ignorance. I thought eels are sexless or could "change" sexes based on the environment (especially when they get "home" to breed)?

 

Phone

[Dave H]

I agree, as Budgie states, that the majority of eels caught by accident are either mis-weighed or poorly estimated. I became so fed up with this last year that I wrote a piece for one of the comics on weighing and measuring eels just after a so called 13 was publicised. I don’t suppose it’s made much difference, but it made me feel better!

However, there are a few waters that have repeatedly produced genuine eels of over 8lbs, sometimes even over 9lbs. Of the four seemingly genuine 9s publicized over the last 2 years, 3 have been from crayfish rich pits. The EA were interested in the relationship between eels and crayfish, as well stocked eel waters often remain crayfish free when others nearby are full of them. The eel is certainly well equipped to eat them. It can access their burrows and has a strong jaw muscles. There was a plan to stock a crayfish infested commercial water with eels and see what happened, but I believe that the owner chickened out when his match customers found out, and rebelled!

I also believe that there are more big eels out there than is indicated by the catch rates. I know of 2 nines that were caught from small pits (around 2 acres) after intensive campaigns by competent anglers-one came after 67 nights, and another after 60 nights, together with an 8 (not consecutive nights, obviously). My own PB came after around 80 nights on a water, and a string of 5s and 6s. You would expect a small water to give up its eels relatively quickly, but it would seem that the slow metabolism, sporadic feeding periods and cautious feeding habits of larger eels make them very difficult to catch. We no longer believe that the biggest eels in a water are caught in the first few sessions. The water you mention above probably contains mostly male eels, as sex is determined by stock density. That doesn’t mean that there might not be the odd big female in there, but having to wade through the smaller ones, and the factors mentioned above, will make the bigger fish very hard to catch. Normally, male eels do not reach 4 or 5lbs in weight, as they return to the Sargasso when they reach maturity at a smaller weight, but if they are unable to return then I would guess that they would grow, but maybe not reach the weights attained by landlocked females in lower stock densities. Not sure about this, though. However, I would put money on finding big eels in a crayfish rich lake with only a few eels. Mind you, odds are I’d lose it, the eel being an unpredicatable beast.

It seems to be generally accepted that the increase in barbel and chub weights is, in part, due to a crayfish diet, especially when there is a low fish stock level. The Old Lea is a good example of this.

 

Perhaps I have to maybe eat my words and am willing to do so as the lake concerned seems to be exactly the place the big one's would frequent. Quite a small lake full of crayfish...Very informative

[Mark7]

All,

 

Let me show my ignorance. I thought eels are sexless or could "change" sexes based on the environment (especially when they get "home" to breed)?

 

Phone

 

An extract that might help:

Near the end of the larval phase, eels enter freshwater where they develop into "yellow eels", and remain in this phase until sexual maturity. It is not until the yellow phase that sexual differentiation of males and females occurs (at a minimum size of 20cm). Males tend to be dominant near the coastal zones, and females further upstream. Eels may take many years to reach sexual maturity, with males generally maturing earlier than females, at between 6 and 12 years; females may take up to 18 years to reach reproductive age (9-18 years). Puberty is thought to be induced by a combination of internal and environmental factors, related to the migration phase (a period of prolonged swimming at depth) and arrival at the spawning ground.

Of the fish maintained in groups, 77% became males, whereas 60% of those maintained in isolation became females. The implication is that both grouping and hormones are involved in sex determination of European eels.

[Phone]

Mark7

 

Thx - I didn't know. Weird creatures aren't they?

 

Phone

[andy_youngs]

I remember reading about some bug that spends years of its life living beneath the Californian desert in a state of suspended animation.

 

Once every few years it emerges, has a shag, and then dies within a few hours. Now that's weird (and a bit sad).

Edited March 1, 2012 by andy_youngs