Trigonostigma Hengeli, does anyone have experience keeping these fish? (Also known as glowlight rasboras)

[rebe]

For simplicity sake, in this post I'll be referring to trigonostigma hengeli as "the rasboras".​

Hello!
I was hoping that there might be some of you who have kept this fish recently or in the past. I'm really keen to hear your opinions and experiences in keeping them, in community tanks but single species tanks too.

My rasboras have been in the tank now for 34 days to be precise. They still "run for the hills" at any slight movement. When everything is still, they'll come out straight away and seem very happy. If I turn my head, stand up or do anything in their line of sight, they hide.
I'm wondering if there will ever be a point where I can walk past the tank, for example, and not frighten them back to what I have now dubbed "the emotional support corner".

The water parameters are perfect, 14 in the group and plenty of plant cover (including a blanket of floating plants.) So I'm trying to figure out if I can do anything to help.

I've read a little bit about dither fish, introducing more easy going and less skittish fish to help the rasboras relax and feel more comfortable. Dithers are used for aggression too but in this context that wouldn't be the case. Unfortunately I don't have tonnes of options if I were to try a dither fish, I don't think my tank is suitable for most or at least that is the impression I have.

I have a high PH at 7.8-ish, and my dodgy test strip says I have these water hardness parameters:
(German Degrees): GH 4.2, KH 2.3

I am not 100% confident in the reliability of the test strips, for the hardness numbers I have.
I'm going to get a proper liquid hardness test soon, and I'm away soon (23rd to the 27th of October).


So to conclude this post, does anyone have experience with these fish? Are they normally this skittish, and should I try to figure out some tank mates to help with said skittishness? I don't know, but maybe this is just natural behaviour for them

 

[WhistlingBadger]

I've never kept hengels, but I've kept harlequins (T. heteromorpha). They are really nice little fish. They like to be kept in large numbers, are very peaceful, and nicely colorful. They do like soft water, so you'll be happier investing in a liquid test kit so you know for sure. My harleys were never skittish, but they had some pearl gouramis flying top cover for them. They were also tank-raised. If your hengels are wild-caught, it might take them quite a while to settle down and decide nothing is going to kill them.

Did you say how big a tank you have?

 

[Byron]

Yes, the first question is, what is the tank size? I've had this species for well over a dozen years, in a couple of different environments (with respect to tank size and other fish).

You might be able to confirm the GH from your water authority's website, just to be certain, but if it is around 4 or 5 you are OK.

 

[Essjay]

We established in another thread that rebe's water company doesn't give results for his address. But we did establish that two towns close by had hardness of 4.6 and 3.5 dH so this water is likely to be soft.

I usually look for postcodes of high street banks and use that to find hardness. So I looked for a bank in your two towns and found "Bank of Ireland, 38 Pearse Street, Clonakilty, Co Cork, P85 NY32".
Entering that postcode in water.ie I get 76 mg/l CaCO3, which is the same as 76 ppm which converts to 4.6 dH (the same unit of measurement as your strip).

Bandon's Bank of Ireland postcode gives 62 ppm/3.5 dH.


It looks as though you already have soft water and your strips are giving a true reading. If you can cancel or send back that RO unit, I would. You don't need it.

 

[rebe]

Did you say how big a tank you have?

Yes, the first question is, what is the tank size?

I should have mentioned it, 105 L, and the dimensions are 75x35x40 cm. Naturally some of that space is taken up by the substrate, hardscape and plants.

 

[rebe]

If your hengels are wild-caught, it might take them quite a while to settle down and decide nothing is going to kill them.

The website doesn't specify, so I've assumed that they are not wild.

https://www.masterfisch.eu/en/freshwater-fish-characidae/390-rasbora-hengeli.html

 

[Byron]

OK. The dimensions are pretty much those of what we in NA term a 29g standard. And 105 liters is 27 gallons, so this makes sense. My experience with this fish was that in its own tank space, it was far more skittish. When I moved the group to a larger tank with tetras and cories, things dramatically changed overnight. You have space for other fish, this would be advisable. Remember, this species tends to remain mid-water, once it is settled.

 

[rebe]

OK. The dimensions are pretty much those of what we in NA term a 29g standard. And 105 liters is 27 gallons, so this makes sense. My experience with this fish was that in its own tank space, it was far more skittish. When I moved the group to a larger tank with tetras and cories, things dramatically changed overnight. You have space for other fish, this would be advisable. Remember, this species tends to remain mid-water, once it is settled.

Thank you, that's really interesting to hear. In your opinion, do you think that without the move to a bigger tank but with the introduction of tank mates, would there have been a similar change in behaviour? Or would you say that in this scenario the size up in tanks was equally beneficial for them in terms of improving their skittish behaviour?

Do you have any opinions about the activity or preferred dwelling level of the new fish? What I mean is, do you think it is important for the other fish to be active and "above" the rasboras so to speak. Would fish that typically inhabit the bottom levels of the tank or fish that are outgoing but not necessarily very active fish be as beneficial?

 

[Byron]

I had a group of this rasbora in with other fish (very small gourami, other rasboras) and it was much the same as in the last tank with tetras and cories. On their own, which was a 20g with just these fish, they disappeared behind wood every time I entered the fish room. But not after being moved. I don't think it matters, so long as the other fish are compatible--meaning, they share all aspects of their environment.

 

[rebe]

I had a group of this rasbora in with other fish (very small gourami, other rasboras) and it was much the same as in the last tank with tetras and cories. On their own, which was a 20g with just these fish, they disappeared behind wood every time I entered the fish room. But not after being moved. I don't think it matters, so long as the other fish are compatible--meaning, they share all aspects of their environment.

That's really helpful, thanks Byron!

 

[Beastije]

At some point, when I started fishkeeping, I had hengeli in astonishing 16 pieces in 54 liters (dont judge me, was in the beginning). half of the tank was a massive anubias, light was not very bright but they would hang around, in one spot, as a group. I kept them with a betta for a while and I kept them with a honey gourami, and in both cases, they worked very well and became a smidge more active. I had them for about five years and they tried to breed regularly, so I would say they were a very low demanding fish. I would not assume yours are wild caught though, they breed readily in captivity and will most likely be from one of the fish farms. Make sure the light is not too bright and they have more places to hide, as more hiding place = less hiding
You wont make a mistake if you add some corydoras, depending on your tank/substrate/layout/readiness, or a honey gourami for example. Bettas are a hit and miss so I would stay away from those. Start with floating plants, if you dont have those, and see if there is a change?

 

[rebe]

Make sure the light is not too bright and they have more places to hide, as more hiding place = less hiding
You wont make a mistake if you add some corydoras, depending on your tank/substrate/layout/readiness, or a honey gourami for example. Bettas are a hit and miss so I would stay away from those. Start with floating plants, if you dont have those, and see if there is a change?

Thanks for responding! There seem to be plenty of hiding places, I think. Lots of hardscape and plants for them. Unfortunately I have aquasoil under most of the sand in my tank, so my tank isn't suitable to house corydoras.
I do have floating plants, a blanket of salvinia auriculata across the surface.
Honey gourami's seem nice but I have gotten the impression that it's wise to stear clear of gourami due to diseases.

My PH is high, 7.8. So I don't expect any breeding activity as much as I'd love to see it.

The only image I have on my phone is from my TOTM entry, sorry

 

[Essjay]

It's dwarf gouramis (Trichogaster lalius) that have the health issues. Honey gouramis (Trichogaster chuna) don't have the same issues, though like with any fish there's always a risk that an individual fish might have something wrong with it, it's not usually dwarf gourami iridovirus or fish TB.

Honey gouramis come in two varieties - natural (golden tan male, grey beige female) and yellow. The fish sold as red honey gouramis are not honey gouramis, they're thick lipped gouramis or a honey-thick lipped hybrid.

 

[rebe]

It's dwarf gouramis (Trichogaster lalius) that have the health issues. Honey gouramis (Trichogaster chuna) don't have the same issues, though like with any fish there's always a risk that an individual fish might have something wrong with it, it's not usually dwarf gourami iridovirus or fish TB.

Honey gouramis come in two varieties - natural (golden tan male, grey beige female) and yellow. The fish sold as red honey gouramis are not honey gouramis, they're thick lipped gouramis or a honey-thick lipped hybrid.

I didn't know that the two were different, that's really good to know. Another option for me to investigate
Thanks, Essjay!

 

[Beastije]

Anyways, with this pH the honey gourami, and most likely the rasboras wont appreciate it. You might have better luck with Neoheterandria elegans or rabbit snails. Not with that substrate though