Unusual female cherry barb behavior

I have 5 cherry barbs (2 male, 3 female) in a 29 gal tank with 4 glass bloodfin tetras. It's a pretty new tank (a few weeks in) and has a combo of live plants (very recently installed) and fake plants. The barbs are VERY active — there is one male that gets on a tear and just darts from place to place pestering anyone in his path (though usually beelining for one of the female barbs). It's a HOB filter and today I noticed one of the female barbs missing. It's not the first time that's happened… both of the males got sucked into the filter tank overnight once (separately). I thought the first one may have died or been eaten; it didn't occur to me to check the filter. Both of the males survived that time, even though one was trapped for almost a full week! So when a female went missing this morning I knew to check the filter. I was able to get her out into a bucket that had a little tank water in it, and scooped her into a net and returned her to the main aquarium. Since then she's been floating in place, largely hanging far up toward the surface and the left side of the tank near the glass. She's not gasping for air, just floating in place. Her body / belly seem a bit bigger than usual, and she's been pretty avoidant of the other fish, only showing much sign of energy to get away from the other peskier barbs. She's been floating like this all day, and I noticed tonight that she had moved toward the bottom of the tank and tipped slightly nose-down, floating up and then sometimes back down slowly.

I'm curious if there's anything I should do; I wondered if it might be swim bladder disease or an injury from the turbulence getting out of the filter, into the bucket, back into the tank. Or perhaps just shock? I had this also happen with one of the tetras recently, and it was also similarly lethargic and avoidant for part of the day but then reintegrated before very long. I've ordered a guard for the filter intake — why they don't just include them for such a common problem I'm not sure (other than charging extra for the accessory?), which should be here in the next couple of days.

Next day update: The barb is still quite still, floating alone in the upper corner, now on the other side of the tank within one of the fake plants... Photos attached, and here's a video link:

29 gal tank, LED hood lighting, heated ~74°F
HOB Filter Aqueon Quiet
Gravel substrate with some live plants rooted w root tabs
Floating red root plants on surface
Water test strip:
Hardness: very soft (close to 0)
Nitrate: <10 mg/l
Nitrite: ~1 mg/l
Chlorine: 0.8 mg/l
KH: 80 mg/l
pH: 6.8-7.0 (liquid test)

Cycled about 20% water yesterday, replaced w dechlorinated water at approx temp (74-76°)

 

Did you buy this filter used? does it not have a grid to cover the opening? if you bought it new it should look like the attached photo and no fish other then fry should be able to get through. So if you bought it new and it doesnt have the part that I circled, return the filter but keep the dirty filter cartridges.


I think that you should block the filter intake with something, don't wait for the part to come in the mail. Any chemical free sponge, craft foam, material from a filter cartridge, part of a fake plant, part of a t-shirt. ANYTHING, just shove it in, as long as the water can still flow through your fine.
The barbs are ok at 74 degrees, but please raise the temperature to 78 for the tetra.
You can add a stress coat product, you can try keeping the tank lights off, you could add almond leaves, offer food with garlic, but your barb may be on its way out sorry.

 

You're correct — my filter shipped without that part. It was part of a bundle from Aqueon. As it happens, the third-party part to cover it arrived today, so I've installed it (it's the green item attached to the filter intake in the attached image). The cherry barb is just hanging out in the open water toward the left side now. Re: the heater: what I have is an Aqueon 100W and it's allegedly preset at 78°F, no ability to change it. But in my experience the water rarely actually exceeds 74°. Should I install a second heater? Is there a recommended placement if I have more than one? (The one I have is to the right of the filter)

 

Interesting about the filter, sorry that that happened.
I would deffinitly want a more stable heater. I am using a single marineland heater in my 55 gallon.

 

in my experience with schooling fish, sometimes there's just that one fish that no one wants to hang out with or is just a loner.

also, do a water change whenever ammonia or nitrite is above 0.5mg/l and i would add some extra dechlorinator since you're test is showing some chlorine

 

As it turns out, the cherry barb in question died last night, found on the gravel floor this morning. Now down to 2 males and 2 females which I worry will put undue stress on the females. But the tank is also likely still finding its equilibrium in terms of fully cycling, so I am thinking it's best to hold off and see how things go over the next week or two. Broader question for those with more experience: is 4 of each (tetras and barbs) too few? I'm considering the next addition to be 6 cory cats for the bottom of the tank and it seems like that might be coming up on the max for this 29 gal community tank. I could potentially add 1-2 more of tetras and/or barbs to encourage shoaling and comfort in numbers, but had also been considering a separate "centerpiece" fish eventually...

 

Ideally it is important to keep schooling fish in larger numbers. The world has decided that 6 is the bare minimum for a school when in reality, more is better. Fish seem to really show their true colors when they are in a larger group of 9+
In the end it comes down to what you choose. But since you asked, 6 cories is also just barely minimum, and some day eventually one will die, and you will have less then 6. If It was my tank, I would get more of what you already have, At least double what you have when the tank is ready. If you had 8-9 cherry barbs and 8-9 bloodfin tetra, you should be ok to add 8-9 dwarf cories.

 

My cherry would harass each other and the bristlenose they were with didn't chill till I had 12.

 

That's good to know re: numbers for shoaling / comfort level... I was worried that having 8-9 of each of these would overcrowd a 29 gal tank, if there is decor / plants etc reducing capacity. Out of curiosity (and I realize off-topic for this section of the forum), would other bloodfins (not glass bloodfins) or other tetras (non-bloodfin) be compatible enough that the tetras are still comfortable in numbers? Or would they need to be the exact same type to be happy together?

 

That's good to know re: numbers for shoaling / comfort level... I was worried that having 8-9 of each of these would overcrowd a 29 gal tank, if there is decor / plants etc reducing capacity. Out of curiosity (and I realize off-topic for this section of the forum), would other bloodfins (not glass bloodfins) or other tetras (non-bloodfin) be compatible enough that the tetras are still comfortable in numbers? Or would they need to be the exact same type to be happy together?

they need their own kind to feel comfortable

 

Schooling fish need to be in schools of exactly the same species. But If the species has an albino version or a color morph, then those fish are the same species and will often, but not always, school together. You also have to be careful, some fish that sound like they are the same are not, like black neons and neons, a green neons which are different species. You need to look for the scientific name to be sure that a fish is the same species with a different color.
The blood fin tetra has one color morph that I know of, the glass blood fin.