Just set up a 20 gallon about 2 weeks ago. Last weekend we bought 2 threadfin rainbows and 2 cory's. Apparently the males can be aggressive towards that females (fish store guy didn't tell us this) and we were supposed to buy 2 females per 1 male. So the female has died. Anyway, I have never kept rainbows before, I'm just wondering what they are like, and if it's possible to keep anything bigger than a threadfin rainbow in a 20 gallon tank.
20 gallon and Rainbows
- Thread starter Erynn
- Start date
Rainbowfish are schoolers and need to be in groups of six or more. Yes, you really should keep the ratios as some types of rainbows are very "randy" that way. It varies with each fish, as does personality, and with genus. I lost a Glossolepis pseudoincisus last night to a randy male. Melanotaenia are a little more laid back in that manner, but they can still do some damage.
Rainbowfish, unless they are very small Blue-eyes genus, shouldn't be kept in a 20 gallon tank. That's too small for them. The minimum, IMO, for Threadfins is about 30gs. They need a larger footprint -- at least 30" long -- and space to swim.
You could take back your Threadfin and look into Pseudomugil gertrudae, the Spotted Blue-eye Rainbowfish. Gertrudae grow to about 1" and a school of 12 or so would be wonderful in a 20g. Do not add any more fish, however, as they should be in a species only tank. The cory will be fine.
Roan
Rainbowfish, unless they are very small Blue-eyes genus, shouldn't be kept in a 20 gallon tank. That's too small for them. The minimum, IMO, for Threadfins is about 30gs. They need a larger footprint -- at least 30" long -- and space to swim.
You could take back your Threadfin and look into Pseudomugil gertrudae, the Spotted Blue-eye Rainbowfish. Gertrudae grow to about 1" and a school of 12 or so would be wonderful in a 20g. Do not add any more fish, however, as they should be in a species only tank. The cory will be fine.
Roan
Thanks for the advice. I was planning on having only Rainbows in the tank anyways, and I knew cory's would be ok with them. I'll go this week and see if the store I go to stocks those smaller Rainbows and maybe go with that. It's my boyfriends tank, I've been keeping fish for 12 years and he's just starting, so I'm trying to let him make the decisions on what fish he wants...I'm just trying to help him along the way. Unfortunately he chose Rainbows....one fish I know nothing about!
the smaller species are more sensitive to water conditions in my experiences. I've never really had problems with threadfins being aggressive towards eachother. Males will display but never had any damage done. Other fish have been problems though, especially with males and their long finnage. I have never really had the threadfins "school", they move about similar to a harlequin rasbora in my experiences and I think a 20 would be fine.
Any of the pseudomugil's should be fine in a 20 gallon. Furcatus seems to be popping up on many lists lately in the US. Someone is wholesaling Furcatus to retail locations under the name signifer so be very wary about actually getting signifer. I ordered some signifer online and got a bag of furcatus. I quickly contacted the seller and they changed their listings to reflect the actual fish. I also noticed a big name chain (forget which one) listing signifer but I doubt they really are. I have seen gertrudae a few times but not too often and they seemed more water sensitive than the furcatus.
I'll probably get an argument here but I also believe Celebes would be fine in the 20. I've been breeding them in a 10 gallon and they are just fine so why wouldn't a 20 work? Kyle
Any of the pseudomugil's should be fine in a 20 gallon. Furcatus seems to be popping up on many lists lately in the US. Someone is wholesaling Furcatus to retail locations under the name signifer so be very wary about actually getting signifer. I ordered some signifer online and got a bag of furcatus. I quickly contacted the seller and they changed their listings to reflect the actual fish. I also noticed a big name chain (forget which one) listing signifer but I doubt they really are. I have seen gertrudae a few times but not too often and they seemed more water sensitive than the furcatus.
I'll probably get an argument here but I also believe Celebes would be fine in the 20. I've been breeding them in a 10 gallon and they are just fine so why wouldn't a 20 work? Kyle
Nice to have someone else who is conversant in rainbowfish here! 
Sorry. Bit of a sore spot there.
I purchased four Glossolepis wanamensis from a shop in Maryland only to have the RML (Rainbow Mailing List) confirm to me that they were not Lake Wanams, but most likely hybrids or multisquamatus. The worst thing is that not only was the tank clearly labeled as "Glossolepis wanamensis/Emerald Rainbowfish", but when I talked to the shop owner about this, he told me he KNEW they were not wanamensis. I'm not even going to go over the rest of the conversation :argue:
He took them back and refunded my money.
I did manage to buy nine 1" unsexed true wanamensis, verified by Gary Lange as RSG line, so I'm happy there
It's appalling that 95% of the Emerald Rainbowfish in the hobby are *not* Emerald Rainbowfish, but hybrids and mislabled Glossolepis multisquamatus. I did a search on Google and Yahoo! a week ago and most of the "wanamensis" I saw in the images that resulted were not wanamensis. Sigh.
I've not done any research into them at all -- nor any other Silversides or Madagascar sunfishes for that matter. I do intend to add them to my Rainbowfish site, but they are pretty far down on my list.
As an aside to the original poster, if you want quality furcatus that ARE furcatus, let me know and I'll point you at the guy I buy all my rainbowfish from. He even had some Pseudomugil tenellus for sale last week.
Roan
That's something I have read, but have not noticed in my gertrudae.snakeskinner said:
I've not kept threadfins; only gone on the advice of Leopardess who has. FWIR they are difficult to keep because of the tiny mouths and difficult to breed as well. Not for the beginner to breeding, IMO.
I've been seeing a lot of furcatus as well, and based on past experiences with regular online shops and LFS et al, I will no longer buy my rainbowfish from an "unknown" entity. I am sick and tired of seeing fish for sale that are labeled as being one thing, and are not. Usually they are hybrids. I, personally, do not care if someone wants to buy or sell hybrids, but don't bloody label them with scientific names or with just a common name that belongs to a different rainbowfish. That's fraud :rant2:
Sorry. Bit of a sore spot there.
I purchased four Glossolepis wanamensis from a shop in Maryland only to have the RML (Rainbow Mailing List) confirm to me that they were not Lake Wanams, but most likely hybrids or multisquamatus. The worst thing is that not only was the tank clearly labeled as "Glossolepis wanamensis/Emerald Rainbowfish", but when I talked to the shop owner about this, he told me he KNEW they were not wanamensis. I'm not even going to go over the rest of the conversation :argue:
He took them back and refunded my money.
I did manage to buy nine 1" unsexed true wanamensis, verified by Gary Lange as RSG line, so I'm happy there
It's appalling that 95% of the Emerald Rainbowfish in the hobby are *not* Emerald Rainbowfish, but hybrids and mislabled Glossolepis multisquamatus. I did a search on Google and Yahoo! a week ago and most of the "wanamensis" I saw in the images that resulted were not wanamensis. Sigh.As I said above, I haven't noticed that at all. It's possible that that is because I schedule two 50% water changes per week on all my rainbowfish tanks, so they at least get one if I miss one.
Heh, *I'LL* probably get an argument here, but since Celebes aren't considered true rainbowfish (closer to the Pseudomugil family), I really have no opinion on that
I've not done any research into them at all -- nor any other Silversides or Madagascar sunfishes for that matter. I do intend to add them to my Rainbowfish site, but they are pretty far down on my list.As an aside to the original poster, if you want quality furcatus that ARE furcatus, let me know and I'll point you at the guy I buy all my rainbowfish from. He even had some Pseudomugil tenellus for sale last week.
Roan
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My celebese are as active as the boesmani. I couldn't fathom keeping them in a 20g. They're in a 55g and act like they'd appreciate more space. Considering that they also get to about 3" I cannot, in good faith, suggest keeping an entire school of them in a 10 or 20g long term. I assume you'd want to keep a school of them as opposed to obtaining a breeding pair/set?
And the threadfin is definitely not for a beginning breeder, IMO. And, from what I've read (for instance, here: http://www.rainbowfishes.org/Breeding.html) the fry of threadfin are quite difficult to feed, requiring tiny foods and very frequent feedings. Even then, the survival rate is very low.
I also think there are more attractive rainbowfish to start out on. Don't get me wrong, they're very delicate and stunning in their own way, but from any distance you lose a lot of the detail because they're so small - and not as active as other species, IMO. IME, they also don't display as much. Still wonderful fish though, if you're willing to deal with some of their idiosyncracies.
And the threadfin is definitely not for a beginning breeder, IMO. And, from what I've read (for instance, here: http://www.rainbowfishes.org/Breeding.html) the fry of threadfin are quite difficult to feed, requiring tiny foods and very frequent feedings. Even then, the survival rate is very low.
I also think there are more attractive rainbowfish to start out on. Don't get me wrong, they're very delicate and stunning in their own way, but from any distance you lose a lot of the detail because they're so small - and not as active as other species, IMO. IME, they also don't display as much. Still wonderful fish though, if you're willing to deal with some of their idiosyncracies.
Leopardess, I guess the number is the deciding factor with the celebese in the 20. I normally keep around 2m/3F when I have them so that wouldn't be a problem.
As for the appealingness of threadfins, I think those, celebese and pseudomugil's depend heavily on water color and lighting. When I have these in a breeding tank, they are washed out and ugly as a wild female guppy. In a tank with tannins in the water and good lights, they are awesome. Especially a group of males displaying for females. I didn't have much problems breeding threadfins except for some assassins that were introduced in the tank by accident. I had one survivor and it's approaching an inch now. I lost my females in my community tank so that's what's holding me up from getting them spawning again. Celebese were no problem, didn't have any luck with the furcatus and had my females killed by some lampeyes I didn't expect to pull out their eyes!
Roanart, that's always the problem with any fish bought from anywhere. I've heard of "respected dealers" selling F0's that had never seen their native country and location data for mut's. Most of the fish you find in a store are labeled like they received them unless they know otherwise. I shop at a very reputable store in San Antonio when I'm traveling through and they always use the names they were given. Eventhough, the employees will usually tell me right away the fish are such and such and not likely what they are called. I bought one group of Furcatus through Neptune aquatics labeled as signifer. I emailed them right after I received them and he was more than apologetic and had the name changed on the website hours later. Obviously not trying to take advantage. He explained they were a cichlid shop and trying to expand but didn't know what he was getting. I realize celebese aren't "true rainbows" but I consider all atherinidae rainbows when I'm talking about them, it just makes it easier Kyle
As for the appealingness of threadfins, I think those, celebese and pseudomugil's depend heavily on water color and lighting. When I have these in a breeding tank, they are washed out and ugly as a wild female guppy. In a tank with tannins in the water and good lights, they are awesome. Especially a group of males displaying for females. I didn't have much problems breeding threadfins except for some assassins that were introduced in the tank by accident. I had one survivor and it's approaching an inch now. I lost my females in my community tank so that's what's holding me up from getting them spawning again. Celebese were no problem, didn't have any luck with the furcatus and had my females killed by some lampeyes I didn't expect to pull out their eyes!
Roanart, that's always the problem with any fish bought from anywhere. I've heard of "respected dealers" selling F0's that had never seen their native country and location data for mut's. Most of the fish you find in a store are labeled like they received them unless they know otherwise. I shop at a very reputable store in San Antonio when I'm traveling through and they always use the names they were given. Eventhough, the employees will usually tell me right away the fish are such and such and not likely what they are called. I bought one group of Furcatus through Neptune aquatics labeled as signifer. I emailed them right after I received them and he was more than apologetic and had the name changed on the website hours later. Obviously not trying to take advantage. He explained they were a cichlid shop and trying to expand but didn't know what he was getting. I realize celebese aren't "true rainbows" but I consider all atherinidae rainbows when I'm talking about them, it just makes it easier
Kyle