Any advise for a mixed tank of Boraras sp. that don't seem to get along?

[Finn]

Hello everyone,

About 6 months ago I bought a shoal of 12 of what were labelled as Boraras brigittae from Kesgrave. Inevitably, what I received was a good mix of several species, which after many days and nights of gazing blankly between my aquarium and photos of different Boraras species and scratching my head I decided included B. naevus, uropthalmoides and merah. Shrugging this off I concluded that they should be able to get along just fine and the tank will simply have more individual characters to enjoy. However, coming forward to today, it has become obvious that there is a bit of a divide, with the brigittae (and 1 uropthalmoides tagging along) shoaling often in a group of around 8 or 9 towards the front of the tank or individually exploring and hunting and the 3 naevus and merah skulking alone in the back behind some heavy vegetation at the bottom or at the top behind the spraybar, hardly ever coming out or mixing with the brigittae at all.

The question is, should I be worried about my poor naevus and merah being nobby no mates? I understand that males of the genus are generally territorial (not like I know how to sex them with any certainty anyway), however I feel as though they've completely rejected the social group as they simply refuse to leave their lairs. No attempts to woo the others have been observed and they don't even like moving far for food. Instead preferring to wait for microworms to gently swirl in the current towards their little faces!

Would it be advisable for me to try to re-home them where they'll have some friends of their own species?

If anyone else has experienced this divide with Boraras species, have you noticed whether it's a gender behavior or down to species or shyness?

As for potential environmental stresses I've tried to keep the tank (60x30x36 cm) as Boraras friendly as possible with low light (1 TMC Grobeam at about 10% for 7 hours), low flow, soft water (not difficult to do in Liverpool mind), lots of plants and leaf litter, feeding mainly live food with their only tankmates being shrimp and snails so I have no idea what else it could be.

I could of course be worrying about nothing, but I'd really appreciate hearing others experiences with these little rascals. I don't want to be unwittingly stressing them out by keeping them alone.

Thanks a lot,
Finn.

 

[alto]

Sorry meant to reply earlier, I suspect you just need to increase numbers ... or add in some "dither" fish perhaps (though I've no suggestions on what might be suitable) - I'd try adding in another 8-10 B sp (look at Seriously Fish for ideas) & see how that goes.

It's also possible that the few fish exhibiting skulking behavior are actually ill as this is also typical behavior for fishes with health issues (especially the reluctant food response) - if I understand correctly this behavior has been going on for months rather than just days or a couple weeks, so if it is health related, fish would only be "slightly under the weather" (eg, a few extra external parasites rather than an infestation) or possible internal parasites, again at a low load ...

Is it possible to remove the main shoal to an alternate tank for a few days? if no change in the skulkers, you don't really learn much, if they suddenly come out & exhibit normal food response, then you've got something definitive to work from (ie try adding more fish & hope for a suitable species mix )
If there's no change, either the "slightly ill" is a good guess OR they need some common fellows to feel more secure ...

Certainly the tank seems large enough, and you've set up a very nice habitat with the low light levels & plant thickets (you might try posting some photos if you're set up that way).
I've not kept these fish in years, but they are very popular in the local shops & I've seen large & moderate shoals of mixed species that seem to get on fine, generally fish are pretty accepting of interlopers joining the shoal as long as they behave suitably ... again what disturbs me most in your description is the reluctant food response.

If you want to go down the medicating road, start with an external parasite med - I use Formalin as it's very effective, generally tolerated well by most fish & inverts & plants & established filters, photo & heat sensitive so "disappears" from the tank fairly quickly, non-staining ...
When treating with any med, always
1) 25 - 50% water change prior (depends on what you do normally, it's always more conservative to perform 25% daily water changes over a few days, than a single large water change - this is important whenever you get behind on your water change schedule OR if there is "something" unexpected in the tap water)
2) increase aeration to maximize dissolved oxygen levels in water - usually just add some "splash" to your filter return or ensure there is good "ripple" of the surface (note this is more effective than adding in an "air pump")
3) tank temperature: lower temp = more dissolved oxygen (most meds sequester oxygen which is why 2 & 3 are important factors) so always choose the lower end of fish range rather than the upper
4) dim lighting: but still enough to observe any negative response to medication, slight is acceptable (some increased respiration, some reduction in activity, some color loss), any spinning or heightened color calls for immediate water change - begin with 50% & perform this rapidly (so if you're using RO etc, make sure you have enough water on hand for at least 2 x 50% water changes before adding any meds)
Adding carbon/charcoal to facilitate removal of meds from tank water is slow, eg, 12- 72 hour process

5) NEVER add anything to your tank where you don't know the ingredients, ask the manufacturer if it's not on the label, don't use anything where active ingredients are not made available, look for dates & suitable storage of the meds - avoid purchasing any meds from shops that don't have temperature controlled areas where meds are stored; ensure labels are current (avoid older stock).


Are there other occupants in the tank?

 

[Finn]

Hi Alto, thanks so much for the in-depth response.

I may add more Boraras, however would they not be overcrowded in a 60 l aquarium if I already have 12 of them? If I were to, I'd need to find out whereabouts I may be able to source them in Liverpool as I'd rather not order from Kesgrave again.

Currently I don't have another aquarium to separate my fish out, however I think I'll purchase a 2 L sudo HOB breeder box to test if they're reacting to one-another, otherwise I do have an 8 L glass bowl that could probably do them for two days or so if I found a mini heater for it.

Regarding the possibility of them being ill or suffering from parasites, I honestly hadn't even thought of that. I suppose because they still looked active, so this may well be worthwhile to investigate. I think I'll try separating them first and then try dosing formalin if I find no change in their behaviour. For some added info on my set-up, I'm running an Eheim classic 215 with a spraybar running the length of the tank (this provides a very mild circulation) along with an air powered sponge filter as a back up, so get reasonable surface agitation from that bubbling away. Temperature is set at 20 C however tends to be higher at around 24 C, particularly around this time of year. Water is simply tap water treated with prime - fluctuating at around 60 to 80 TDS with the tank sitting at about 100 TDS. I'll try and get some pictures but it's not the most photogenic!

As for other occupants, There's just the aforementioned shrimp (Neocaridina sp. and Caridina mariae) and Malaysian trumpet snails (Melanoides tuberculata), however I was thinking of getting a pair of liquorice gouramis or a small wild type betta - though not until I've resolved this issue, and possibly not at all if I end up having to get more Boraras!

Anyway, thanks again, I'll try and set up a suitable means of dividing them in the next week or so and report back with my findings,
Finn.

 

[alto]

I suppose because they still looked active,

If fish are active & breathing normally & just seem a trifle shy (& are known to be a shier fish), I'd shelve the notion of treating the tank - or the fish.
Instead try increasing the shoal number with another 6-8 fish, trying for non-brigittae, I'm assuming this is a 60cm tank, filtration sounds excellent, plants, regular water changes, so tank should easily support a good sized shoal of these tiny fish.
I'd even still add in the liquorice gouramis once everything's sorted, though they prefer a bit warmer than 20C (eg 22C is the minimum I'd set for them) - ldcgroomer may still have some home-bred pairs for sale, after more posts you'll be able to see the "swap" forum).

2 L sudo HOB breeder box

These can be quite stressful for fish, though if you were able to fill it with plants/moss etc it might work out OK (I quite liked this video I found) - this one seems a decent size (length) & I like the water flow.

Your 8l bowl should be fine short term (you could look at placing it on a heat mat if you can't find an economic mini heater), again add loads of moss etc & then just transfer your sponge filter over for the "trial".

 

[sciencefiction]

Regarding the possibility of them being ill or suffering from parasites, I honestly hadn't even thought of that. I suppose because they still looked active, so this may well be worthwhile to investigate.

Hey, I agree with alto. If the fish are hiding, stationary, hiding under filter intakes, near heaters, not eating, not exploring, regardless of their social number, they may actually have parasites. Parasites don't kill or rather kill very slowly, months or even years. The most common issue with fish that goes unnoticed is internal parasites to which they only succumb(die) when their immune system is weak because of other factors like stress from not being in a natural social group, move to from shop to owner, water quality issues, bullying, etc... Fish in nature are riddled with parasites and worms but their immune system deals with it for life because of low stress. The problem develops only in aquariums(think wild discuss for example) And eventually, in months, other fish will be affected if some are infected.
Typical behaviour of fish riddled with parasites is still being active enough, look well enough, but behaviour is odd and worrying, eventually they may stop eating which is a sure sign it's gone too far. And obviously they spook and hide and stay in one spot a lot. Trust what you see. The best I'd recommend is Kusuri wormer plus, but that may kill shrimp and will kill snails. It's harmless to any fish older than 6 weeks or so, and it will rid of most possible stuff, if followed up for a second treatment.

If you can take a video of the fish in question or just research yourself a bit to see what's normal behaviour and what's not.

 

[Lindy]

Interesting thread considering I've just ordered 25 boraras maculatas! I don't have any paros available but do have young sexed pairs of homebred betta channoides about to become available. These are facinating fish and are mouth brooders. Let me know if you are interested.
Female

Male

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