Blind barbel

Cass suggested I open this area off, so to start whilst I haven't noticed any major diseases or parasites recently we used to notice a lot of bling barbel being caught from the area Henley to Marlow. Not noticed it in the Windsor area. The barbel had one eye which was totally opaque and in a few cases both eyes affected. I was told this was caused by an eye fluke. It obviously didn't stop them feeding as I used to catch a fair few at Hambleden nearly all blind in one eye. Would be interested in any other observations

Mike

I've never seen it on a barbel but over the years I've seen quite a few one eyed pike due to the condition. As you say it doesn't stop them feeding but I bet the pike miss quite a few strikes at live fish as a result.

Just a note to correct you. Its Henley On Thames [Oxon] not Henlow [Beds].

I think TWA did a study on this in the mid/late 80's and think Ray Walton commented on this some while back.

Mike

.

"Neil, the pike that you have seen with this condition were they all Thames fish?"

No, I've had a couple from the Thames but also from lakes although I can't remember which at the moment.

surprised no-one has mentioned the mid twenty mirror carp on the semi tidal, it has been well known for at least 8 years, is blind in one eye and like other fish mentioned, seems to lead a normal life,
would be interesting to know the fluke/conditions name, is there a remedial cure, does it transfer to the other eye, hows it spread, where'd it come from, and can we become infected, although I weren't planning on lending my contact lenses

Jim,

Taken from here: http://www.fish-disease.net/diseases/eye_flukes.php


Symptoms:

Fish with this condition will have white specks inside the lens of the eye. This can lead to further damage, ranging from cloudiness of the eye to rupturing of the lens and blindness. In severe cases the eye may actually be pushed out and removed from the socket, leaving the fish eyeless.


Cause:

The larval stage of digenetic fluke parasites, such as Clinostomum, Posthodiplostomum and Diplostomum spathaceum. The parasite lodges in the lens, humour or retina of the fish's eye. If present in large numbers, severe damage can occur. Minor infestations may go unnoticed. The life cycle of these flukes begins when fish-eating birds and other animals ingest fish infected with the parasites. Once ingested the parasites mature in the intestines of the host animal where they produce eggs. The eggs are then deposited into the water where they hatch and infect the livers of aquatic Snails. The parasites then develop into a second and third larval form before leaving the Snail to seek out a fish host. This type of parasitic infestation is most common in wild-caught fish and fish kept in ponds.
---

Also have a look at this site: http://www.thefishsite.com/articles/102/invasion-of-the-eye-flukes

It is orientated towards trout farming, but very interesting never the less.

As far as a cure, it is possible in a closed environment where the intermediate hosts can be removed and the water treated to kill the parasites, but in the Thames this would obviously be highly difficult. My reason for asking how widespread this condition is in the Thames is because the susceptibility of any animal to a parasitic infection depends largely on how fit that animal is in the first place - think stray versus pet dog analogy. Perhaps if the prevalence of the condition were to increase in wild Thames fish it could be seen as an indication of the fitness of a specific fish species population declining, possibility due to other reasons such as poor water quality. Just a thought..

Cass

love it mate, that was pukka, what a life these parasites lead, and I thought our lives were complicated

My good god!!! That is truly some process of transference, 'unbelievable' and astonishing!!!

We'll have to try and train some dog fish to help these poor fish get around!

Pardon the pun!


Richard