Pikehead

[The-Wolf]

anyone have any personal experience with pikeheads Luciocephalus pulcher?

I've seen fishbases' page for them as well as a few other and was wondering what the smallest fish
that can be safely kept with them.
some say any fish 3/4 the length of its body could be pray as they max out at 7 inch
would 5-6 inch fish such as giant danios, elegant rasboras be ok?

apart from the predation aspect are they very aggressive, aggressive or semi-aggressive?

what kind of set up would you keep one or two in?

 

[CFC]

Pikeheads NEED soft acidic perfect water to live and are very very prone to bacterial infections which appear from no where the moment the water isnt to their liking, so unless you live in a softwater area with low nitrates an R/O unit is a must for keeping them. I had a few some time ago and lost them all when i missed one weeks water changes because i couldnt get to the shop to buy my water that week, but before that i must have treated them for bacterial fungus at least half a dozen times.

They are aggressive between themselves but i kept mine in a species tank so i dont know if they would be aggressive to other fish, my instincts say they wouldnt be. Their mouths are huge for their size but fish of 5 inches or more should be perfectly safe.

 

[nmonks]

No personal experience, but everything I've heard says they're very difficult to keep alive for any length of time. I'd be interested to hear how you do with them.

I'd not mix them with anything. Are you setting up a blackwater tank for them? In which case your issue is going to be pH stability and enough zeolite to remove the ammonia from a tank that can't support biological filtration. These things come from pH 5.5, near-zero hardness swamps and streams, and typically when such fish are kept in harder water their immune systems simply can't cope with the bacteria. So keep these at pH 6+ of 3 degrees+ dH and they die after a few weeks/months. I've experienced this with Hemirhamphodon halfbeaks that come from the same sort of habitat.

That's my understanding, anyway.

Cheers, Neale

(Edit: CFC beat me!)

 

[The-Wolf]

well I kind of thought I wouldn't be able to keep them at this moment in time,
shame they look great and are quite colourful in the shop.

thanks CFC and Neil for the info, perhaps someone else can use this info in the future.

 

[nmonks]

Wolf, as I've mentioned before elsewhere on this forum, there's nothing wrong with rainwater. Works great for these sorts of fish. A rainwater butt costs a few tens of pounds to buy and install, and in this fair country of ours it fills up pretty damn quickly!

Once you've set up a tank with rainwater and, say, 5-10% tap water, you can aim to keep VERY softwater fish quite easily. Peat filtration is optional, and I wouldn't actually recommend it. Instead go for a pH buffer to lower the pH and keep it there, since you won't have any carbonate hardness on your side. Zeolite in a bubble-up box filter is fine for filtration in an under-stocked tank.

Your main problem is water changes: acidification in these tanks occurs very fast, hence the need for buffering coupled with water changes to dilute the acids (including nitric acid from nitrate, not just organics) and top up the buffering capacity.

Cheers, Neale

 

[CFC]

I've never had the guts to try rainwater, living on the outskirts of London and directly under the flight path of Heathrow i just cant help feeling that the rainwater could be contaminated with something nasty from the air.

 

[nmonks]

Filter it overnight through carbon (or PolyFilter) if you're worried, and treat with a good dechlorinator to remove heavy metals. It's hard to imagine even the most grubby rainwater will be dirtier than London tap water (50 mg/l nitrate!) especially after it has been sitting in your copper and/or lead pipes.

I did clean my roof though, especially the gutters. A lot of ivy and stuff was getting into the rainwater butt, turning the water brown. The fish didn't seem to mind, but the aquarium was looking a little too Rio Negro for me! I have an article on soft water aquaria issues over at WWM that might interest.

On the plus side: rainwater is free and ecologically "nice". (Compare with RO water, which is an indefensible ecological disaster -- uses electricity, nasty chemicals for manufacturing, and wastes 10 gallons of water for ever 1 gallon RO water produced.)

My take is this: fear of rainwater in aquaria is like those mums who drive their kids to school because they're frightened of child molesters. Odds of child being abducted, less than one in a million. Odds of child being injured/killed in motor accident, one in a few thousand. In other words, driving your child to school puts it at more risk that walking to school. But because drivers feel "in control" they think they're safer, even though they quite obviously are not.

Likewise with rainwater, because it's something we can't control or easily test, we're wary. But tap water has masses of nitrate (hole-in-the-head, sick mollies, etc.) and other pollutants but we think its fine because we're familiar with it.

Cheers, Neale

I've never had the guts to try rainwater, living on the outskirts of London and directly under the flight path of Heathrow i just cant help feeling that the rainwater could be contaminated with something nasty from the air.

 

[The-Wolf]

I just don't have the space atm to set up yet another tank