"Black spot" in roach.

[DenisO]

The swan mussel theory would make sense because everytime any part of the Beult is dreddged there are literally millions of shells in the dirt that comes out.

[Vagabond]

monkeyboy:

Your right abouth the nematode worms. Dont the snails get horrible worm like growths making birds eat them.

Err TREMATODE, not nematode, in the case of black spot.

 

There are plenty of parasite life cycles (trematodes, nematodes, and many others) that involve one or more species of snails as intermediate hosts. Only a few of them involve fish as well.

 

Glad to see confirmation from Bruno - 'cos I have always found Van Duijn's book a pretty reliable source of information, even though it was written over 40 years ago.

 

DenisO There might be an INDIRECT link between the Swan Mussels you see after dredging and the black spot

 

The reasoning goes like this.

 

1/ Plenty of Swan Mussels indicate the water chemistry is favourable for shell formation.

 

2/ If the chemistry is right for shell formation in mussels, it might also be right for shell formation in water snails.

 

3/ So there could be plenty of water snails there also.

 

4/ Water snails carry black spot (I don't know which particular species of snail does this, but no doubt someone does)

 

Next time you see the mussel shells in the dredged silt, have a closer look for any smaller shells - it would be interesting to know what else is there.

 

[ 12. April 2003, 09:39 AM: Message edited by: Vagabond ]

[poledark]

Vagabond, do the chub also suffer from Black spot?

 

Den

[Chris Plumb]

I've certainly caught them with it - (see earlier post!)

 

 

Chris

[poledark]

I did see that post Chris but the question was for Vagabond re the upper Medway chub. I used to get a lot of roach with black spot in the Eden (tributary of the Medway) but never saw a chub with it. None of the chub I caught from the Medway at Penshurst or Poundsbridge had black spot, but maybe the spots are not so obvious on chub.

My thinking was also to do with what caused it i.e. if it is a parasite that attaches itself then why not all species?

 

You see Chris, as usual I am trying to muddy the waters abit more

 

Den

 

[ 12. April 2003, 07:11 PM: Message edited by: poledark ]

[Bruno Broughton]

[ 12. April 2003, 07:26 PM: Message edited by: Bruno Broughton ]

[HarroldBishop]

having caught several roach over the last week i can safely say none of them had black spot. However some of my koi karp have black and orange spots and they look really nice-thats why i bought them.

[Vagabond]

poledark:

Vagabond, do the chub also suffer from Black spot?

 

Den

Not, so far as I know, in the Upper Medway. In addition to the Upper Medway itself, I fish a stream running through several dams before it joins the Upper Medway. There are stacks of roach, rudd and chub in both stream and dams - none caught in the last ten years have shown black spot.

 

Incidentally there are plenty of swan mussels in the dams - must keep a lookout for the mussel glochidia next season.

 

Having said I have seen no black spot recently, I saw this picture in the Times Magazine this weekend.

 

 

I think she has been swimming in the River Teise - can you confirm Cranfield ?

 

I would have posted it sooner, but did not want to excite Poledark too early in the morning, nor put Chesters off his lunch.

 

[ 13. April 2003, 01:00 PM: Message edited by: Vagabond ]

[rickster]

the roach and perch in the river Tillingham in Rye east sussex are covered by black spot, it dont effect them tho, just last summer i had a net full of them most over the 1lb and half and my biggest perch at just under 3lb

[HarroldBishop]

well in my local drink all the zots had more than 33mm of gary-scred mis-multipalmutations (spots). i was digusted and went to argue with the water company. They assured me that only shreemers with 16' tennonfly could cause such a denilo and thats as far as it went. i was disappointed to say the least