A Forktail Amongst My Threadfins!

[daizeUK]

I expanded my shoal of threadfin rainbowfish today and only when I got home I realised one of the females was actually a Pseudomugil furcatus, forktail blue-eye.
 
She seems to be shoaling a little with the threadfins but also spends some of her time alone.  I feel bad that she has no conspecifics in the tank.  Will she be alright shoaling with the threadfins or should I look into providing her with company?
 
I was thinking of adding more threadfins at a later date but I could consider adding forktails instead...
 
Any advice?

 

[Baccus]

I would try and get her some more forktails to keep her company. My spotted blue eyes stick together like glue and I imagine that forktails too would see safety in numbers of their own kind.

 

[daizeUK]

Thanks Baccus, I think I will.  I reckon I have space for another 8 small rainbows.  Do you keep other kinds of rainbows in the same tank and do they shoal together?

 

[Baccus]

I currently have threadfin rainbows and pygmy rainbows together and they happily shoal together, the bonus is that they are in different families so no cross breeding. If I was keeping  other melanotaenia I would not mix these together as they are often closely related and cross breed readily. Many types of rainbow fish in Australia are known only by the creek or river system that they are found in and only have subtle differences to rainbow fish found possibly in the same region but their creek systems never connect. Effectively creating two different sub species.

 

[daizeUK]

Any idea if P. furcatus and I. werneri can cross-breed?  I don't think it matters as I'm not expecting any fry to survive in this tank.  But I have noticed the threadfin males are showing some interest in the forktail female.
 
I have read one source which suggests that these two species shouldn't be housed together as the forktails can nip the long threadfin filaments.  But I've read other sources saying they can be kept together happily. 

 

[Baccus]

I wouldn't expect them to successfully cross breed, the males might just be showing interest because its a female and she doesn't have any of her own species to hide amongst. I know my crazy male endlers (with plenty of female endlers in the tank with them) thought they could breed with my much larger female pacific blue eyes when the pacific blue eyes where first introduced to the tank.
 
I think keeping the two species together may depend on a lot of other factors that many sites may not include, such as the size of the tank the fish are being housed in, other species being kept with the fish (e.g. guppies which are notorious fin nippers being kept with say threadfins), also the numbers of each species being kept. If both shoals have enough of their own kind then I suspect most of the time they will stick to themselves and only mix at certain times. Also plantings and other structure can come into play with how well some species are going to co-habit.

 

[daizeUK]

The males might also be showing interest because she is the largest female in the tank and frequently goes off by herself, which the males might take as indication that she is looking for a spawning site.  She has been receiving a disproportionate amount of interest from the biggest threadfin males.
 
The tank is 120L Juwel Lido, current stocking is 15 threadfins (8 male, 7 female) plus the forktail female, 3 small male platies (2 of whom will be re-homed when I can catch the little blighters) and 6 amano shrimp, heavily planted in the centre so lots of broken lines of sight.
 
I'm thinking of upping the numbers to 5 female & 3 male forktails and possibly a few more female threadfins.
 
I was also interested in adding a shoal of either pygmy cories or CPD's at some point, if there is space.
 
Any thoughts?

 

[Baccus]

Upping your numbers of the threadfins and getting more male and female forktails sounds like an excellent plan. I would try to get a 2:1 ratio between the males and females just like guppies so that a single female is not getting harassed constantly by males. Although I have watched my male threadfins plenty of times and rather than bugging the females mine tend to show off and do their fin wiggles to entice the females down to his chosen spawning site, and the only spats I have seen has been between the males, but any arguments are quickly forgotten and they go back to doing what ever they where doing before.
 
With corydoras I would look at any of the three dwarf/ pygmy species from memory corydoras hastatus likes to swim about in the middle of the tank as well as snuffling about the floor, these would look really effective mix shoaling with your threadfins and forktails.
 
If your looking for another species of fish that would be peaceful and mix well with your other stockings Rasbora maculata would give you a lovely strong flash of red, the beauty of them is they are another egg layer and remain small. I personally like to see a large tank well planted properly filled with small fish all going about their business over a huge tank housing one grumpy large fish that cant be mixed with anything else and even plants are destroyed.

 

[daizeUK]

Cheers Baccus!  Unfortunately I'm limited by hard water and basic pH so those dwarf rasbora are out for me.  I'm not even sure that pygmy cories would be a good idea, my water is so hard (about 300ppm).
 
I feel the same about lots of little fish though, I'm loving the displays I'm getting from this newly expanded threadfin shoal!
 
I went and asked for advice about mixing these species on a dedicated rainbowfish forum and the guys over there gave me bad news and good news...
 
The bad news is that they don't recommend mixing Pseudomugil furcatus with threadfins as they grow too large and boisterous and would probably scare the threadfins into hiding.
 
The good news is that I incorrectly identified the blue-eye female, she's not a furcatus but a gertrudae, Spotted Blue-eye, which they tell me are far more peaceful and more suitable for mixing with threadfins!

 

[Baccus]

That's excellent news about being a spotted blue eye, I have a little shoal of these and they are gradually increasing their numbers supplying me with tiny fry fairly regularly. My little spotted blue eyes are in their own tank with just native shrimp and a couple of native snails.


and their tank


I am surprised that they said the forktails would get to big to mix with threadfins, I would have thought they would be of very similar size. The largest blue eyes I have seen have been pacific Blue eyes especially the Harvey Creek Blue eyes.