Re: [RML] Deformed fish.

Nick Thorne (nick at nativefish.asn.au)
Fri, 27 Feb 1998 13:15:47 +1100

I'm not sure about published work, but I do know from NFA's experience
with breeding native fish, that excessive temperature while the eggs are
incubating often produces a high proportion of deformed fish, in the
order of magnitude that you describe. In the case of our hatchery when
breeding trout cod this can be caused by abnormally high temperatures in
October and by the fact that our hatchery is not a purpose built
structure and suffers from heat at times, despite our best efforts to
prevent the problem. I see no reason why such things might not happen
in the wild, especially if the water in question has had a significant
amount of the stream side vegetation removed, allowing for higher water
temperature. I suppose unseasonably hot weather could do it in a
particular stream in any case.

Cheers,

Nick

------------------------------------------------
Nick Thorne nick at nativefish.asn.au

Native Fish Australia
http://www.nativefish.asn.au

-----Original Message-----
From: Rob Wager <raintree at mail.cth.com.au>
To: RML <rainbowfish at pcug.org.au>
Date: Friday, 27 February 1998 12:52
Subject: [RML] Deformed fish.

>I've just finished some aquatic survey work in a Brisbane Creek. Water
flow
>in the creek is maintained by sewage effluent - yuk. Amazingly enough
there
>are native fish in the creek. But a significant proportion (about 15%)
of
>the firetail gudgeons have deformities like missing vertebrate, bent
spines,
>cleft upper jaw and missing gill covers and fins.
>
>I suppose the deformiries could be caused by toxins or heavy metals,
but it
>could be poor diet, inbreeding (unlikely) or some other environmental
>stress. Does anybody know of any work anywhere on fish deformities?
>
>Thanks in advance
>
>Rob Wager
>Raintree Aquatics Pty Ltd
>Aquatic Environment and Aquaculture Specialists
>1002 Caboolture River Road
>Rocksberg QLD 4510
>AUSTRALIA
>Phone: 07 5496 7939 Facsimile: 07 5497 0022
>Email: raintree at mail.cth.com.au
>