Harlequin Rasbora

[Chri$]

I currently have 7 harlequin rasboras in a 200l tank.

When the light is off they are fine, swimming around mid levels in a loose school as you would expect, but when it's on they hover just above the gravel and appear very pale. All water water stats are fine, 0 ammonia, 0 nitrite etc.

Am i right in thinking adding to the group would help? Maybe up the school to 10 or 12?

Thanks in advance

Chris

 

[WILDER]

Mine are usually stay mid water not above the gravel.
How long are they pale for.
If there pale something wrong, fish can be pale when sleeping, or turning tanks lights on, but if they pale all the time it means stress, or illness.

 

[Chri$]

Thanks for the reply wilder.

They are pale when the lights are on, but they colour up a lot when the tank lights go off, they also become more active and move up to the mid levels.

As i said all water stats are good. They are sharing a tank with corys and a german blue ram at the moment - nothing bothers them at all.

They are showing no signs of illness - but i do think it could be stress? perhaps they need a large school for the tank size?

 

[WILDER]

How long have you had them as If they have come in from the wild it takes them time to get used to the lighting in the tank.
I would turn the light off if there stressed, and gradually build the light time up.

 

[Chri$]

I have had these fish for nearly 2 years. There were in a 100l before i upgraded and were fine, i've only started having this problem since i moved them into the 200l.

 

[Lateral Line]

When did you move them? Is it just readjustment nerves? Rasboras are picky about being moved.

 

[Chri$]

They were moved over 2 months ago.

The only thing i can think of is increasing shoal size - do you think this would help?

Thanks.

 

[Lateral Line]

7 is a reasonable group size, but fish like this are always happier in large groups, so it can't do any harm to add more. It is odd though. After 2 months they should have settled, yet the behaviour you describe seems to indicate insecurity.

Is there anything else different? Substrate, planting level? Are they feeding alright?

 

[Chri$]

Thanks for the reply LL.

They are feeding ok at the moment, they don't take food from the surface but wait for it to float down to middle/lower areas.

Substrate is exactly the same, this tank is planted more densley however. I am thinking about adding some floating plants to provide a bit of cover, hornwort or similar.

After 2 or 3 hours of light they seem to get used to it and venture about a bit but still staying at low levels, then as soon as the light goes off the start swimming in the upper areas where you would expect.

 

[cbr6fs]

I'm very new to this hobby so please take that into consideration.

But i have 11 Harlequin Rasbora's in my 120L tank, if anything they're full of energy, the only time i seem them still is if i get up in night, they tend to all face the same way and just sort of float.
I'm guessing they're sleeping or at least relaxing.


I don't know if it's just mine, but they're cheeky buggers, every time my hand goes in the tank, they swim towards it not away from it, and start sucking on my skin
Every time i hoover the substrate at least 6 swim up the hoover thing, weird as it seems they really seem to enjoy swimming against the current, the little tails going mental till i stop the flow.



What are you feeding them?


Again i only have experience of mine, but they go mental when food is added, it's literally like feeding a group of starved piranha's.
They seem to eat absolutely anything as well, they go crazy for flakes, brine shrimp eggs (dried) they also tackle the Cory's shrimp pellets which are nearly as big as the fish



Cheers
Mark

 

[Chri$]

Thanks for the reply Mark.

I am feeding them on flakes and the occasional treat of brine shrimp, blood worms etc.

How long have you had your harlequins?

The only conclusion i can come to is to increase the group size. They were in a 100l before and seemed happy but the problem started when i moved them into the 200l.