Are Columbian sharks ok with full saltwater?

[daviem]

Basically I have some sort of bacteria growing in my aquarium and I think I found a treatment, however I have noticed a lot of products are either fresh water or saltwater only, this goes for beneficial bacteria ph testing kits etc so I wanted to know if Columbian sharks are happy in full saltwater at 1.021-1.026? Does anyone know how they do long term and at what size is it ok for this salinity or is it not good for them. I have done research online but some say as adults some say straight way and some say it’s not good for them.

[Bas Pels]

As far as I know the adults live in sea...

[Jools]

Here's a picture of one I caught in the Caribbean Sea off the northern coast of Venezuela. At this age they can move between freshwater and marine.

Jools

[daviem]

Here's a picture of one I caught in the Caribbean Sea off the northern coast of Venezuela. At this age they can move between freshwater and marine. 1555_G.jpg



Jools

Cute , so they can, I increased my salinity by just 0.001 today and they stopped eating and started hiding, I dont think I mixed the salt in the bucket long enough though, it had all dissolved but the salinity in the aquarium rose by 0.002-3 the went back to what I intended and increase of 0.001, however also the temps fell to 73.4f/23c because of a problem with the heater so Im not sure if thats caused the issue of them not eating.

[Viktor Jarikov]

I believe they are capable of living in marine water from young age too... and Jools shows it.

I've never experimented with salinity, so can't offer any insight on their responses to the salinity changes. I imagine since they usually inhabit estuarine tidal zones, the salinity changes are of no concern to them but how quick or slow a change should be to exert stress I'd not know. You are in position to teach me and perhaps others.

[daviem]

The issue I have is I dont want to hinder them in anyway putting them in full marine conditions at such a young age, If I do it, it will be in slow increments by adding more salt into each bucket during the water change, increasing the salt amount in each bucket to raise the overall aquarium salinity by 0.001 until it reaches 1.020 unless theres a problem with the bucket method having a high SG?

[Viktor Jarikov]

I'd probably do more searching and reading online on the topic of how young is too young to go into full marine because there is no telling when you'd be helped sufficiently here, could be today, or could be never. IDK who keeps brackish or marine tanks on here. I am a 100% freshie. I think most or almost all people here are too. Perhaps Jools knows and could tag someone(s).

The plan to slowly increase the SG with WCs 0.001 unit at a time sounds reasonable to me, again, on paper, not from experience or knowledge.

It will take 20 weeks or 4.5 months during which time hopefully your pretty little rockets will do some growing and will have put on perhaps a couple of inches.

Are the sharks still stressed by the increased salinity and have no or suppressed appetite? Are they still hiding? I think they shouldn't. They are not of the hiding type, unless perhaps the lighting is too bright and/or there is little cover nearby to dive under in case of danger, as they perceive it.

I am sincerely excited to see someone actually doing what these fish need for a change, that is, transferring them slowly into brackish and marine, and reporting it along the way. This is the first time in my experience, so in a way, you are a trailblazer to me

It'd be awfully nice and helpful if you too chose to keep all your posts on these fish and what you are doing in one thread for an easy and convenient reading and learning experience now and for posterity.

[Fishmandavew]

Columbia’s sharks are born in fresh water to my knowledge and return back to the sea as they grow. As such kept three in fresh until around five inches when I started increasing the salinity of their six foot tank. Finally over the course of 6 months reaching 1.025 by which time they were living with a porcupine puffer, baitfish and zebra moray and around a foot in length. Finally moved them on at 16” to an lfs for their huge display tank to highlight the size and requirements of this fish which is all too often sold as a freshwater community fish

[daviem]

I'd probably do more searching and reading online on the topic of how young is too young to go into full marine because there is no telling when you'd be helped sufficiently here, could be today, or could be never. IDK who keeps brackish or marine tanks on here. I am a 100% freshie. I think most or almost all people here are too. Perhaps Jools knows and could tag someone(s).

The plan to slowly increase the SG with WCs 0.001 unit at a time sounds reasonable to me, again, on paper, not from experience or knowledge.

It will take 20 weeks or 4.5 months during which time hopefully your pretty little rockets will do some growing and will have put on perhaps a couple of inches.

Are the sharks still stressed by the increased salinity and have no or suppressed appetite? Are they still hiding? I think they shouldn't. They are not of the hiding type, unless perhaps the lighting is too bright and/or there is little cover nearby to dive under in case of danger, as they perceive it.

I am sincerely excited to see someone actually doing what these fish need for a change, that is, transferring them slowly into brackish and marine, and reporting it along the way. This is the first time in my experience, so in a way, you are a trailblazer to me

It'd be awfully nice and helpful if you too chose to keep all your posts on these fish and what you are doing in one thread for an easy and convenient reading and learning experience now and for posterity.

I contacted someone who keeps a lot of columbian sharks he did say they should be 4 inches to up the salinity but they should be ok at this size up to a salinity of 1.010 until they reach 6 inches. They have started eating, I couldn’t find any help anywhere regarding the growth on the ship aka the bacteria although I removed the ship I wanted to know if I should have added treatments.

They kept hiding until 2 days ago when I removed the towel and now they’re much calmer, they started eating again though I am having serious problems with the aquarium, it just won’t cycle on top of that the heater had to be changed to an online one because the internal one rusted after like a month and burned me when I held it so for that and to help the cycling I bought an external filter to fit an online heater and I got one with UV to kill a potential bacteria in their aka the growth, just as I thought great let’s start the cycle attempts again I noticed the temps rising constantly with the heater off, checked the new filter it’s very warm so I turn the Internal UV off the filter cools a bit but the temps continue to rise, so currently I have an uncycled aquarium keeping them safe with prime and amguard, back to using old heater as the filters no good whilst trying to get it sorted. I would keep people updated I also noticed online it’s hard to get info on how to look after them and a lot of it varies so I have no problem with that I would be happy to, just hope I can sort the ongoing aquarium problems out.

[daviem]

Columbia’s sharks are born in fresh water to my knowledge and return back to the sea as they grow. As such kept three in fresh until around five inches when I started increasing the salinity of their six foot tank. Finally over the course of 6 months reaching 1.025 by which time they were living with a porcupine puffer, baitfish and zebra moray and around a foot in length. Finally moved them on at 16” to an lfs for their huge display tank to highlight the size and requirements of this fish which is all too often sold as a freshwater community fish

Thanks for confirming their size when you started it conforms what the other guy said which is near 6 inches to go to higher salinities, I will be trying to increase the salinity slowly up to 1.010 over the next few months, then wait until they get to 6-8 inches to start increasing again until they’re in 1.021, I know it’s a long tome away still but would that be beneficial at 1.021 or 1.026 when they’re adults.

[Fishmandavew]

To be honest I don’t think it will matter. Depending where you are in the world you will find differing salinity, especially as it varies with temperature too.
If you can get a steady temperature, anywhere from 1.021 to 1.025 would be classed as full marine conditions.

[daviem]

Ok I increased the salinity of the aquarium from 1.005/1006 to 1.007 and this appeared small lumps across the fishes sides I have a picture I will attached then the columbian shark keeper I was talking to advised me it maybe parasites and more salt will kill the parasites so I increased the salinity to 1.008 but the fish went frantic trying everything to get out Of the aquarium as far as pushing on the edges at the bottom to swimming frantically across the top so I removed 25% water then added RO water directly to the aquarium this brought the salinity back down to 1.006 they are swimming calmly now but look exhausted. What’s going on, do they have parasites or as someone told me is it possible the salinity increase was too quick? and the salinity increase burned their skin? Or is it a parasite that either likes or doesn’t like the salt? What’s your views?

[Lycosid]

Ok I increased the salinity of the aquarium from 1.005/1006 to 1.007 and this appeared small lumps across the fishes sides I have a picture I will attached then the columbian shark keeper I was talking to advised me it maybe parasites and more salt will kill the parasites so I increased the salinity to 1.008 but the fish went frantic trying everything to get out Of the aquarium as far as pushing on the edges at the bottom to swimming frantically across the top so I removed 25% water then added RO water directly to the aquarium this brought the salinity back down to 1.006 they are swimming calmly now but look exhausted. What’s going on, do they have parasites or as someone told me is it possible the salinity increase was too quick? and the salinity increase burned their skin? Or is it a parasite that either likes or doesn’t like the salt? What’s your views?

The issue with salinity is that it changes the osmotic pressure on the fish. A fish's internal salinity is somewhere between freshwater and full saltwater, and so a fish in freshwater has water "pushed" into its body by osmosis and a fish in full saltwater has water "pulled" out of its body by osmosis. A fish then needs physiological mechanisms to counteract this. In the case of a fish that changes between fresh and saltwater over time (ontogenetic change) these mechanisms also shift as the fish grows. This is why a Columbian shark will die as an adult if it is placed in freshwater - it's lost those mechanisms and developed other ones.

My guess is that Columbian sharks probably also take some environmental cues - if the water they are in is saltier they probably speed up developing those saltwater-tolerant mechanisms. But I can't find any studies on this, so I'm just taking an educated guess.

I would suspect that what's happening to your fish is that when the salinity changes on them it feels really strange to them until they adjust. The question is how fast they would adjust. One thing you could do is bring the salinity up slower. If you measured the amount of salt you need to add to the water to bring the salinity up to your target you could add the salt to the water in small batches over several days (testing the salinity, of course, in case your calculation was off) and let the salt slowly dissolve into the water. I once had a research student pour a bunch of salt into a tank (with no residents) rather than stir the salt into water first, and the salt took almost 24 hours to all dissolve (it was also ALL the salt needed to go from full fresh to full salt).

However, given the lack of data on this species, your best bet is to just pay attention to the fish and make sure they seem comfortable with their salt level.

[daviem]

Ok I increased the salinity of the aquarium from 1.005/1006 to 1.007 and this appeared small lumps across the fishes sides I have a picture I will attached then the columbian shark keeper I was talking to advised me it maybe parasites and more salt will kill the parasites so I increased the salinity to 1.008 but the fish went frantic trying everything to get out Of the aquarium as far as pushing on the edges at the bottom to swimming frantically across the top so I removed 25% water then added RO water directly to the aquarium this brought the salinity back down to 1.006 they are swimming calmly now but look exhausted. What’s going on, do they have parasites or as someone told me is it possible the salinity increase was too quick? and the salinity increase burned their skin? Or is it a parasite that either likes or doesn’t like the salt? What’s your views?

The issue with salinity is that it changes the osmotic pressure on the fish. A fish's internal salinity is somewhere between freshwater and full saltwater, and so a fish in freshwater has water "pushed" into its body by osmosis and a fish in full saltwater has water "pulled" out of its body by osmosis. A fish then needs physiological mechanisms to counteract this. In the case of a fish that changes between fresh and saltwater over time (ontogenetic change) these mechanisms also shift as the fish grows. This is why a Columbian shark will die as an adult if it is placed in freshwater - it's lost those mechanisms and developed other ones.

My guess is that Columbian sharks probably also take some environmental cues - if the water they are in is saltier they probably speed up developing those saltwater-tolerant mechanisms. But I can't find any studies on this, so I'm just taking an educated guess.

I would suspect that what's happening to your fish is that when the salinity changes on them it feels really strange to them until they adjust. The question is how fast they would adjust. One thing you could do is bring the salinity up slower. If you measured the amount of salt you need to add to the water to bring the salinity up to your target you could add the salt to the water in small batches over several days (testing the salinity, of course, in case your calculation was off) and let the salt slowly dissolve into the water. I once had a research student pour a bunch of salt into a tank (with no residents) rather than stir the salt into water first, and the salt took almost 24 hours to all dissolve (it was also ALL the salt needed to go from full fresh to full salt).

However, given the lack of data on this species, your best bet is to just pay attention to the fish and make sure they seem comfortable with their salt level.

Thanks, They seem rather happy at this salinity 1.006, the bumps have gone considerably down to tiny dots but I’m still wandering if it was a reaction to the salinity or a parasite or both.

[daviem]

Ok, the tank still has not cycled and I cannot keep the ammonia down it keeps rising to over 1ppm with no nitrites or nitrates, despite adding live bacteria for salt and freshwater and having a ton of biomedia so I want to raise the salinity with every water change by 2 points until I get to 1.021, theyre just over 3 inches, considering I cannot access bacteria from a brackish aquarium but only marine I think this is the way to go, what do you guys think? I want to do it over the next two weeks, so every day or other day raise the tank by a salinity of 0.002, then add saltwater bacteria. The salinity is currently 1.008, with this rise from 1.006 they tried to get out of the tank for 1 hour then calmed down and are ok now.

[daviem]

Someone said on another forum that they acclimated their fish straight from freshwater to marine the fish were fine in a reef tank for a short while then died, so no I’m stuck, did the salinity kill them or the reef environment.

I added yet more live bacteria yet my aquarium won’t cycle. Won’t even start still no nitrites or nitrates but rising ammonia.

[Viktor Jarikov]

Yeah... perhaps we could focus on the cycle because this sounds mighty strange at the face value. I don't know what to say or how to help.

[bekateen]

Someone said on another forum that they acclimated their fish straight from freshwater to marine the fish were fine in a reef tank for a short while then died, so no I’m stuck, did the salinity kill them or the reef environment.

Setting aside the cycling issue for a moment (which is the bigger issue), I'll pitch in something about the switch from FW to SW. In some fishes (and I can't speak for this species), the migration and adaptation from FW to SW involves days of transition, and changes in hormone levels (the hormones growth hormone and cortisol are involved in SW adapation, whereas prolactin and cortisol are considered the FW adapting hormones). So if your friend acclimated the fish from FW to seawater too quickly, the fish might have been unprepared. Saying a fish looks "fine" is, as we all know, often way off the mark.

Regards, Eric

[Lycosid]

Someone said on another forum that they acclimated their fish straight from freshwater to marine the fish were fine in a reef tank for a short while then died, so no I’m stuck, did the salinity kill them or the reef environment.

The salinity change, probably. You might be able to survive in very warm weather and very cold weather, but if I took you from a very hot environment and threw you directly into the walk-in fridge it would be bad for you.

As bekateen said, a lot of fish take days/weeks to adjust to new salinity. A few species that live in tidal environments where the salinity changes in hours are just sort of "ready to go", but unless you know that's what you have going straight from freshwater to saltwater is a terrible idea.

I added yet more live bacteria yet my aquarium won’t cycle. Won’t even start still no nitrites or nitrates but rising ammonia.

I've never thought much of live bacterial cultures. What sort of filtration do you have for these bacteria to live in? In my opinion that matters more.

[Viktor Jarikov]

Beyond using them to jump start the cycling process and shorten it from an average of 4-6 weeks to 2-3 weeks, I've never used the bacterial over-the-counter cultures either.Not on regular basis. The BB's don't live in water (to any appreciable degree) but on surfaces.

If it has been months and the cycle doesn't seem to start, the situation need to be seriously troubleshooted. Something is way way wrong here.