Backyard Aquaponics
A place to discuss aquaponics

Catfish spines are not "venomous" as such, but are spines covered in all the usual stuff you find in the bottom of a creek, and so can lead to infections at puncture sites.

Stonefish are venomous, and you use hot water to denature the toxins. They have a sac at the base of the spine with the venom. If you step on them, the pressure will "inject" the venom into the wound.

Not surprised the assassin knows all about poison

Jaymie, are you SURE?

i'm specifically talking about tandanus catfish

Yes, and so am I. They have very sharp spines, but no Venom.



Alright, after a further search, I have found one site that says they have venomous spines.
www2.dpi.qld.gov.au/fishweb/2171.html


Seriously, I have dissected catfish at university and there were no venom sacs on the fish. The spines are sharp and will give you a painful jab, but NO VENOM.

If anyone is interested there is a discussion forum on catfish
http://tandanuscatfish.6.forumer.com/index.php?

Oh yeah, freshwater stonefish or bullrouts also have venomous spines and the punctures are treated with heat.

So the really nasty puncture that hurts for days that you get if you handle flathead (ocean flathead) when we go fishing, is just nasty bacteria? There doesn' appear to be a venom sac, I had assumed that there was an excretion that covered the spine, and probably most of the fish that hurt you...

Do they need to have a venom sack to have a poisonous substance in, say, their slime. Possibly it is the strict use of venom here that is the issue. Regardless, good to avoid these spikes hey

VB this is what I was trying (ineloquently) to ask :-) Thanks

I that first link references the ratio of mucus to venom in the tandanus...........

dunno, i've certainly not disected any.............

but i've also read a blog where someone stuck by one did the hot water trick with great result...............

would expect general muck / slime to give a nice infection but not extreme pain almost instantly.

this may well be a case of me falling victim to one of my greatest pet hates, inet regurgitation..................


i want this resolved for my own piece of mind!

Hi Jim,

Just read your thread right through - great system!

Did I read right that you didn't do any gravel washing!? How muddy was the gravel to begin with? What's this mysterious "filter" you mentioned?

Great pics of the catfish!

Scottie,
yes- no gravel washing- water was VERY muddy for about 6 weeks. I couldn't see the bottom until the end of the 6 weeks . And didn't really become crystal clear for about another 2 weeks. The gravel still looks a bit dirty on the surface but lower down it appears to have been washed reasonably clean.
The filter is just a 12 litre mop bucket with lots of 6mm holes drilled in the bottom. It is about half filled with polyester(?) padding/wadding from spotlight. Like the thick filterwool you get in aquarium shops. All return water goes into the bucket which is suspended over the fish tank. I have so far changed the filterwool twice and it needs to be changed again about now.
KD -I try to flood the GBs to about half an inch below the surface of the gravel but the evaporation rate is so high that I usually top up every 2nd or 3d day and the GBs flood to just above the gravel for the next day or so.
Today I topped up but forgot the flow was happening for about 10 minutes and have had to readjust the float levels etc. A real pain. So I am going to add a 100 or 200 litre barrel to the system as a topup unit so that each top up can only be 100l.

Jim,
F&F decided a tap timer would be good enough, after he did what he called a 10000% water change by forgetting the hose was on :-)

KP-be a bit hard to fit a tap timer to 40mm pipe- doable but perhaps more trouble than it is worth.
I also like the idea of actually being able to top up with a known amount of water in an idiot proof manner- my tiny/tidy mind likes to record such details.

yeah no probs, just spreading the solutions :-)

I agree, I want the same, preferably connected to my roof so it can fill in it's own time, be topped up with tap water and then dumped into the system.
Perhaps a 200L or bigger drum, with measurements to make the most of rainwater. Then release only the 100 you want into the system.

Or better yet, set a float valve at the low point in your sump, and any time it gets lower it automatically takes a touch more from your drum.