Hatchetfish behavior

Olympia

I picked up 6 marble hatchets a while ago. They seem to be settled. I'm curious if they are an active species or not. Mine seem to spend the majority of the day under the floating plants, not moving around too much. I thought they'd be more active. Is this normal, or are they still settling a bit?
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jaysee

I have heard that that is normal.

adadkins1

They should become a little more active as they get acclimated to the tank, mine did anyway. I purchased 8 for my 55g and 2 died in the first two weeks for unknown reasons, but now the 6 that made it past that first critical two weeks are thriving. At first they did what you say, just stay in the floating plants and keep to themselves. However, after several days mine became more rambunctious. They started playing around and schooling with each other. They do this off and on. Most of the day they just kinda chill out like other Characins (Neon/Glowlight Tetras for example), but then they will have a little fun here and there. Overall they are one of my favorite fish, they are great conversation starters.

Olympia

Good to know.
They're swimming around a bit more. They prefer to stick to the unlit section of the tank. (Only half the tank is lit up).

adadkins1

Yeah, they love staying around the floating plants. Hopefully they keep moving around more and more. Mine are a ball to watch when they decide to play around.

Byron

I have maintained this species, Carnegiella strigata, for many years, it is my favourite of the hatchets, especially the "fasciata" form [the two forms are illustrated and described in our profile].

They do tend to remain fairly quiet, but when the mood strikes them they will suddenly play, sometimes in a pair, or more a group. "Sparring" as I term this behaviour in the characins. Two of them circling each other so rapidly you can hardly see them also occurs.

They will normally avoid bright light if they can, so that is fine. And also water currents; many articles still mention how this species supposedly prefers (and needs) to stand in a swift current, but this is not accurate; they do not like currents. Mine have always remained closer to the opposite end of the tank from that where the filter outflow is positioned.

Floating plants are mandatory, but make sure there is open water between; this is where Water Sprite is so useful. This species generally prefers open water if it can find it. Most probably because it naturally feeds on insects that fall onto the water surface.

And, get a few more if you can. This species needs larger groups, I would say no fewer than 9, but more if you have the space. Mine were at their best in groups of 20+. I noticed less activity when they were in smaller groups around 6-9.

Byron.

Olympia

I've noticed them chasing each other around too. They don't seem to stick together very much, I've noticed they tend to stay in pairs more than a group. And they do tend to stick to the parts of the aquarium where there are no floating plants. The Hornwort twirls around and there's open areas surrounded by plants. I'm thinking to eventually replace it with Water Sprite or something that'll send roots down, the Hornwort takes up a lot of real estate in the mid section of the tank.
I think they're still shy, when I watch them they stay still, but last night when I was working on the tank beside them for 3 hours they were pretty active.
Hmm, well mine look like the second photo, a smaller mid-stripe. The profile isn't very clear on which variety that is though.
9, you say. That's doable. The profile says 6 so that's what I grabbed. Hopefully the store will get a few more in because there weren't that many around. Extremely cheap fish, which surprised me. But I'll be sure to increase the school size. They seem to be doing fine with me so I don't mind getting some more.

Edit: Wait, no I think I have the ones with the thicker mid-stripe. One of them is in my avatar. It's just not as dark as the one in the profile.

adadkins1

Don't mean to hijack, but have you ever had issues with them being suceptible to Ich, Byron? I've been thinking about getting some more to up my current 6, but now I'm reading all these things about them bringing Ich in.

jaysee

Ich is VERY easy to treat, so the concern of ich should not deter you. Any fish (even if it looks healthy in the store) can bring it (and a multitude of other pathogens) into your tank, which is why it's important to quarantine new fish.

Byron

It is true that they are more prone to ich than some fish. I had it once or twice with this species, but I've also had it with different fish too. But definitely quarantine if at all possible, for 2-3 weeks. All new fish.

I agree ich is fairly straightforward to treat, but lately I have noticed this worsening. It is interesting that for more than 10 years I never quarantined, and I was bringing in new fish almost every week with never a problem. But more recently things have not been this rosy. I've had protozoan-infected fish several times, and ich more. And quite severe. I currently have a group of new fish in quarantine; they looked fine for just over a week, and then literally overnight they were covered in small spots and hanging near the substrate. This was very sudden, and two of the 14 fish were dead the first day, and another followed. With my usual treatment lasting just over a week they recovered and seem fine. Subjecting an entire tank of 100+ fish to treatments just because of ich on new fish should never happen.