My hillstream has had a bit of a personality transplant. I've had it about 18 months. It lived peacefully with my goldfish, but about 5 months ago I set up a tank of white clouds and moved it into there and since then it has flourished, grown half an inch, and seemed very happy that it gets all his algae wafers to itself without sharing with the goldfish.

It has never even seemed to notice the white clouds and they leave each other alone. Recently however it has started chasing them away if they get too close - not just a movement in their direction to scare them away, it properly chases them up into the tank and swims around a bit.

I'm baffled!

I've never heard of hillstreams showing any aggressive behaviour, let alone to other species.

It gets plenty of food and has lots of little caves and a plantpot it loves. It isn't especially shy and comes out at feeding time.

It doesn't seem ill - I hope not, I'm very fond of it, funny little thing.

Should I maybe try adding another loach?

Any ideas why it's doing this?

Hillstream Loaches should always be kept in groups a minimum of 5 is recommended. I have kept a group of these loaches but have never had any problems with them they are normally quite friendly and would rather hide than have a confrontation with another fish. They also require a normal diet as you may find it is also eating the fish food as they require a varied diet which includes brine shrimp and the likes algae wafers alone are not enough. You may wish to read this link on the species.

http://animal-world.com/encyclo/fresh/Hill...streamLoach.php

Thanks.

I do vary its diet, not just algae wafers - it's easier for him to get all the food that sinks now that he's not with goldies.

I have a good current and airstones to oxygenate the water, smooth stones and hiding places.

Again it comes back to the fact that it is not normally agressive, and is with peaceful tankmates that don't bother it. It's like someone has swapped the fish.

Would you suggest getting another loach then?

iclayton- i have 2 hillstream loaches in my goldie tank, and they normally chase each other around.
i think this is fairly normal behavior and it's probably begun now that it has something "it's own size" to chase around.
just make sure your white clouds don't end up with frayed fins.

Re: frayed fins - they should be ok, they're faster than him!

I'm going to my LFS tomorrow anyway for supplies so I might take a look and see if they have any loaches that look ok. I'd like to watch two interacting. I'll make sure I buy an extra cave too!

hehe i figured the white clouds would be ok.

watching two hillstream loaches is funny..
they'll chase each other around, and sometimes in circles too...
and just by the fact that they look like little underwater submarines,
it's all quite silly.

when i feed my goldfish progold,
they'll actually push the pellets around so they'll crumble and eat the little chunks!
they're adorable.

Yes, I think I'll definitely get another. Dyson is my favourite of all the fish I have, to say he was such a random impulse purchase last year. I love the way he flicks the gravel up around him like he's trying to bury himself. I want him to be happy, so I shall try and get another tankmate!

Thanks.

Ok, I got another. Called him Sheldon, randomly. Dyson objects to his presence somewhat but they will hopefully get along ok soon enough.

You want to up your group to 3 if you can as they are group fish plus larger group means less likly hood of them fighting among themselves.

Cautionary word just in case it happens sometimes they can stick themselves to the tank glass and be unable to free themselves so need a gentle hand to release them i have experienced this first hand with one of group i had. Just something to watch out for

Really? I've had the first a year and a half and never had that happen. I'll remember that though.

I don't really have the tank space to put another one in. They aren't fighting, just marking out the boundaries I think. Seems to be setling in fine.