Hatchetfish experience

[Beastije]

Hi guys, just wanted to post here my recent experience with the marble hatchetfish, that I have had for over a month now, if anyone else is curious about them.

From all the articles I read before obtaining them I was afraid they will be jumpy and easily startled and will be finding even the smallest gaps in the covers to try to get out of the tank. Everyone is warning about them being skittish, how they can easily overeat, how they are suicidal.
Granted, my experience is very brief, but I want to say that so far, neither of the statements is true.

I believe all depends on their tankmates, the hatchetfish are very static, very slow moving, hanging on the surface in their own group, minding their own business. I believe, if they were accompanied by fast moving fish, they could become stressed or skittish, being constantly "harassed" from their staying still and doing nothing. As long as their tankmates are small, slow or mellow, they are very easy, peaceful, (static) fish.

I have not yet seen or heard any of mine jumping above the surface, I have not experienced panic or stress when cleaning, when submerging hands in the tank, even when scrubbing the glass all around with the sponge, when putting the water in the tank with a hose or a bucket, they do not mind, they simply drift on the other side, stay in the open surface not too far away. No jumping away, no scared behavior.

They do not like too cold water change or too quick, as they tend to hangout 5 cm below surface after such a water change, otherwise they never leave the surface. Feeding therefore is a bit of a challenge, dried food, flaked food yes, that stays on the surface, but live or frozen is a bit of a hassle, have to drop it in slowly so it doesnt sink, they will not swim down for it.

They are very much shoaling fish, reports from other keepers who had lower numbers show aggression and division when low in numbers, as long as you have good numbers, they stay together all the time, near each other.

Overall, behavior-wise, they will be considered boring, because they dont do much, but they are interesting to look at and fill the surface water level void if you have it. Just beware of their tankmates or they wont make you that happy.

Cheers

 

[DoubleDutch]

Hi guys, just wanted to post here my recent experience with the marble hatchetfish, that I have had for over a month now, if anyone else is curious about them.

From all the articles I read before obtaining them I was afraid they will be jumpy and easily startled and will be finding even the smallest gaps in the covers to try to get out of the tank. Everyone is warning about them being skittish, how they can easily overeat, how they are suicidal.
Granted, my experience is very brief, but I want to say that so far, neither of the statements is true.

I believe all depends on their tankmates, the hatchetfish are very static, very slow moving, hanging on the surface in their own group, minding their own business. I believe, if they were accompanied by fast moving fish, they could become stressed or skittish, being constantly "harassed" from their staying still and doing nothing. As long as their tankmates are small, slow or mellow, they are very easy, peaceful, (static) fish.

I have not yet seen or heard any of mine jumping above the surface, I have not experienced panic or stress when cleaning, when submerging hands in the tank, even when scrubbing the glass all around with the sponge, when putting the water in the tank with a hose or a bucket, they do not mind, they simply drift on the other side, stay in the open surface not too far away. No jumping away, no scared behavior.

They do not like too cold water change or too quick, as they tend to hangout 5 cm below surface after such a water change, otherwise they never leave the surface. Feeding therefore is a bit of a challenge, dried food, flaked food yes, that stays on the surface, but live or frozen is a bit of a hassle, have to drop it in slowly so it doesnt sink, they will not swim down for it.

They are very much shoaling fish, reports from other keepers who had lower numbers show aggression and division when low in numbers, as long as you have good numbers, they stay together all the time, near each other.

Overall, behavior-wise, they will be considered boring, because they dont do much, but they are interesting to look at and fill the surface water level void if you have it. Just beware of their tankmates or they wont make you that happy.

Cheers

Agree only think some of the experiences depend on the species and their size.
C.strigata and marthae are super fish

 

[Fremlins]

My only experience with hatchetfish was many years ago when I tried to keep some in my old 40g tank. It had a reasonably close fitting lid but they still managed to jump through the gaps, strand themselves on the lid and bake under the light.
You may be right about their tankmates being the problem - it occurs to me that I had some tiger barbs in the tank at the time and although they aren't aggressive fish they do dash about a lot.

 

[Byron]

The environment in the tank is very important, and this includes tankmates, and floating plants with some open water spaces between them.

The majority of jumping out is usually during darkness. I have had all species in the genus Carnegiella for years, on and off, and the C. strigata were without question the most prone to jump, and all of this occurred at night in darkness; in the morning I might find a dead hatchetfish on the floor if I foolishly forgot to close the cover glass after feeding the day before, or a couple times they would jump and get wedged between the cover glass and the mid-tank brace. Always at night.

 

[Beastije]

Yeah, so sadly have to confirm, after 6 months, the same experience as others, despite super mild flow and tankmates. At night, hatchetfish jump out either fully or lodge between some things, so out of the initial 14 I had, now I only have 7.
Silly fish, would not recommend

 

[Wills]

Yeah, so sadly have to confirm, after 6 months, the same experience as others, despite super mild flow and tankmates. At night, hatchetfish jump out either fully or lodge between some things, so out of the initial 14 I had, now I only have 7.
Silly fish, would not recommend

Thanks for coming back to update this thread we all learn from our mistakes but its a vital part of this forum that we help others learn from them too. I for one, know the forum is littered with my past errors and lessons.

Wills

 

[GaryE]

I see a lot of people reporting things like this after a month - we all do it. It takes a year to have much of an idea of a fish and how it behaves, and 5 years is better. I wish I'd known that before I wrote some stuff...

I love hatchets, all the species. They jump when they're scared, and if I were that size in Amazonia, I'd be pretty nervous. A lot of fish jump as much, but not nearly as well. They can really launch themselves.

 

[Mikeyboy123]

Happens to us all. I recently had 6 chilli rasboras jump out through little gaps around the glass cover. The only thing I can put it down to is that my filter was sounding very odd so I took it out to clean it and put another filter in for a few days. The new filter had a higher flow rate and even though I tried to mitigate this by positioning the outflow toward the back of the tank, the high flow rate must have spooked them and 6 jumped out. I've put the old filter back in after cleaning it and the 2 remaining fish seem happy with it. I will be getting replacements. Lesson learned, and I've now got a tank with a proper lid. Never again going for anything that has any openings.

 

[Beastije]

Now I am pondering, in the past 2-3 months since posting this, I only lost one fish, so maybe the progress of jumping out has slowed down.
Since they are shoaling, the question is, should I get some more again and when or is it worth it.
I did notice that when I had 14 they were somehow separated, some fish hanging out solitaire, now that I have 6, they are very stable, at one place, ALWAYS together, 3-5 cm gap between them. Feeding them is still a nightmare, but I am assuming none is dying from hunger.

I am just wondering if to give them another chance, if so I need to do it when I still have another tank that could be used as a quarantine

 

[Byron]

Shoaling fish show a propensity to shoal more tightly when there is a smaller group, out of stress. Ten or more will allow them to feel safer, and spread out more. These appear to be Carnegiella marthae, as best as I can tell from the photos. You should not have problems with jumping out if the tank is covered.

 

[Beastije]

Shoaling fish show a propensity to shoal more tightly when there is a smaller group, out of stress. Ten or more will allow them to feel safer, and spread out more. These appear to be Carnegiella marthae, as best as I can tell from the photos. You should not have problems with jumping out if the tank is covered.

They are supposed to be strigata but you had me doubt it so I am googling differences.
I have a tight fitting lid. They jump on the under glass strengthener or when I put in a thermometer or accidently not fully close one side of the lid after a water change, like 0,5 cm or even less space between the sliding glass and the border. It sucks cause i forgot to close after a water change or a feeding for like one night in a month and they jump that night ?!
Will check the stock that is available and will go measure them

 

[Byron]

They are definitely not Carnegiela strigata. For reference here are a couple photos of the two species C. strigata and C. marthae together. The C. strigata in photo 1 are I believe lineage 2, and those in the second photo are lineage 1, but that doesn't really matter. There are two distinct forms but both have a "marble" pattern that the other species does not possess.

 

[Beastije]

You are right, damn it, and this was a reputable fish store one of the best here but the fish is an import so maybe a mess there. I didn't notice in 10 months, shame on me, but at least it makes sense why they are so small )

 

[Beastije]

Thinking about this, I feel like I made rudimental mistake (for the past 10 years?!). I just got a new fishtank and it has the extra glass panels along the rim, which I am understanding are strengthening the glass itself against bowing, no idea how they are called in english.
My tank housing the hatchetfish ofcourse has them too, and I just realized I could have put the cover glass right on those panels, instead of having them on the plastic sliders 2cm above the panels. This could have solved the issue with the fish jumping onto the side panels and dying there.
I will definitely try this approach when I get the new hatchetfish batch, which should be in two weeks or so, depending on the import dates.
I still have those six, since May not one jumping out, so yay! They also are starting to learn how to eat the M sized fluval bug bites I have, so good news if I dot manage to get the S size. It involves some chewing and having mouth full of the pellet, which is cute.
Cant believe I was so stupid though to not realize how to use the panels correctly...

 

[Beastije]

Another update on this In december I had 6 hatchetfish. I bought 8 more, 6 survived quarantine, added them to the main tank after that, had 12.
6 months later, I have 8 and again, all loses during the initial period of hierarchy, since then, all peaceful, all hanging at the same side, all behaving like a big group happy. No loses for 5 months.
I just dont understand these fish.

Anyways, I love that I had these oddballs, but once they pass, never again. The nerves!