Dwarf Rainbowfish - Melanotaenia Praecox

[kiriyama]

Just a quicky, I purchaed 4 today and they are in a 20 Gallon tank, want to buy another 2 tomorrow, is 6 to many, what would he minimum number be in a 20 gallon ?

 

[Croftuz]

Hi dude, great fish!!!

I have 10 8 males and 2 females in my 29 Gal (120L)

I also have other fish bringing up my total to 18.

With a Big Eheim External (2028) giving me good flow, and some minor plants growing well i have a really happy mature shoal.

The more femlales you have, the more aggressive the males get. The theory being if the female/s are 'owned' by the biggest alpha, the other smaller males just accept the hierarchy. The more females there are, the more the other males will compete and harass the females and each other.

This is good really as the males have a far more colorful appearance and often flare their red fins in an early morning display..

I love the species, a great choice!

~Paul

 

[kiriyama]

Hi dude, great fish!!!

I have 10 8 males and 2 females in my 29 Gal (120L)

I also have other fish bringing up my total to 18.

With a Big Eheim External (2028) giving me good flow, and some minor plants growing well i have a really happy mature shoal.

The more femlales you have, the more aggressive the males get. The theory being if the female/s are 'owned' by the biggest alpha, the other smaller males just accept the hierarchy. The more females there are, the more the other males will compete and harass the females and each other.

This is good really as the males have a far more colorful appearance and often flare their red fins in an early morning display..

I love the species, a great choice!

~Paul

Cheers Paul, they really caught my eye, 3 smaller ones and 1 larger one, nice subtle blue on the flanks and dark red fins, tight shoal then they zip off in all directions, I have them in with 2 Julidochromis Dickfeldi, 4 Altolamprologus Compressiceps Dwarf and a BN Plec(which I never see ), thought I would try them out as dithers for the Dwarfs and it seems to have worked, for about a week now they are clinging to there shells but since adding the rainbows they are out and about a bit. The rainbows seem very active and fairly peaceful, hope the peaceful bit remains, I have 2 long plants , don't know the names but I have been told they are for oxygenating the tank, a large rock pile at one side and a smaller one at the other, large external filter. Sound ok ? Any special requirments ?

 

[drobbyb]

I have kept a few Melanotaenia praecox before. These guys don't get very large so quite a few can be kept in a 20 gallon. Ideally you would want more females than males to spread the male's aggression around. In some cases the males will stress the females to the point of death if not enough are kept in the school. I recommend to keep at least equal numbers of females to males if you are going to keep both sexes. All male tanks do just fine if you aren't planning to breed them.

The minimum number to keep is 6. Praecox are sensitive to water quality, as are all rainbows, and need regular frequent large water changes. One 50% water change per week is sufficient to keep them healthy. Also, they need a fair amount of vegetable matter in their diet. While they will survive on tropical flakes alone, this doesn't meet their needs. It's true that they need a high protein diet, but not all animal protein. I find that feeding a staple of high quality spirulina flakes with live or frozen food a time or two a week keeps them thriving. Be careful with frozen bloodworms though as they have a chitinous head that can get stuck in the digestive tract of dwarf rainbows often killing them.

They make great dither fish though. Many african rift lake cichlid keepers employ them to help spread aggression and to draw out shy specimens. It's a common practice that has been used for years, adding more color and flash to their tanks.

Enjoy them!

 

[N0body Of The Goat]

Aren't the Praecox going to be battered by any African cichlids, even the similar sized shell dwellers?

Certainly sounds an interesting community mix!

Presumeably Pseudomugil furcata is another possibility for this, given their top/middle life?

 

[drobbyb]

Well, we are talking about shell dwellers in this instance. They are known for being shy and sometimes need a little coaxing to get them out of their shells. If we were talking about your standard run of the mill African cichlids, like malawis, I would suggest M. praecox's larger cousins, say boesemani's, lacustris, or some of the other larger species.