Rivulus punctatus and Austrolebias nigripinnis

[gacp]

Hi all

The goods news, is that the first batch of A. nigripinnis fry (the F1) have hatched and are growing very well.

The bad news, is that... I have an idea :-P The plan is to house some 5 males and 5 females in a 70 l tank, planted in pots interspersed with peat substrate (7-8 cm deep) in an irregular checkerboard pattern, so that each male can claim his own territory. The plan is to use this tank to also house some 6 Rivulus punctatus, which I expect will claim the upper layer, heavy with floating and emerging plants (Eleocharis sp., Hydrocleis nymphoides, Salvinia sp., Limnobium spongium, Potamogeton gayii, &c. I'll leave a few cm airspace, and put a tight glass lid. I'll probably also add a few Cnesterodon decenmaculatus (a livebearing killie) and some Paleamonetes argentiuns (a glass shrimp). All species are sympatric, although I do not know that they are truly syntopic.

Will this work? Any suggestions?

[gacp]

Hey, no comments? None, from anyone?

[TyroneGenade]

Sounds OK to me... Most killies can tough it out in a community. I find Aphyosemions and Chromaphyosemions mix well, but Fundulopanchax and Epiplatus don't play nice with others...

Most annuals will not bother other killies. I have some Simp. sp. Bahia South and reticulatus in with some Chrom. splendopleure. No problem about territory.

[gacp]

Sounds OK to me... Most killies can tough it out in a community. I find Aphyosemions and Chromaphyosemions mix well, but Fundulopanchax and Epiplatus don't play nice with others...

Most annuals will not bother other killies. I have some Simp. sp. Bahia South and reticulatus in with some Chrom. splendopleure. No problem about territory.

Thanks for the confirmation. I guessed so, but still "I am but an egg" and always ask the masters

But I got another doubt now? Will Austrolebias spp. mix, given room? I am thinking about A. nigripinnis and A. patriciae, which are very different yet about same size; I was recently presented with a few A. patriciae eggs (from Chaco, to be precise, the southernmost known location for the species), so now I am temped to house the 2 spp. together. Oh, I know this will make a mess with the eggs, but I'd love to see them interact---provided the interaction is not akin to ethnic cleansing!

[mk_ultra]

I definately forgot where I read this, ( I will find a source for you) but many times a killi eco-niche will only support 1 specific genus of killi. ie only 1 Austrolebia per eco-niche. I have to really look fo the source...

I personally would not keep them simply because fish of a genus always have the threat of crossing. Better safe than sorry, IME.

[mk_ultra]

I found the source
It's in the A Hobbyists Guide to South American Annual Killifish
starts of on page 17 about symbiosis. I have a pdf version of this that was freely distributed. If you do not have a copy pm me your email address and I'll send it. Or if the admins show where to post I can upload it.

[gacp]

I definately forgot where I read this, ( I will find a source for you) but many times a killi eco-niche will only support 1 specific genus of killi. ie only 1 Austrolebia per eco-niche. I have to really look fo the source...

I personally would not keep them simply because fish of a genus always have the threat of crossing. Better safe than sorry, IME.

Thanks, good points. I do have a copy of the report.

I am not quite sure what you really mean by "eco-niche". Of course, it is pretty much a dogma that 2 species won't occupy the same niche---is this what you mean?

Around here (Buenos Aires), there are plenty of records of sympatry, and often syntopy, for several killies. Austrolebias bellottii and A. nigripinnis are often found together, and sometimes along with A. alexandri further north, and A. robustus and A. bellottii south of here and of course there is A. (Megalebias) elongatus, but this is of course a predator so it is out of the question. More to the point, the A. patriciae I have bear the same locality as populations of A. nigripinnis (Río de Oro, Chaco, KCA 34/05) but I will need to check whether this is merely sympatry (same area) or actual syntopy (they live fin to fin). BTW, my own nigripinnis are from Punta Lara, some 800 km south of Río de Oro.

In any case, my point was more about how the 2 spp. interact in aquaria of some 70 l.

About hybridization, sure, it is a danger, and one of the things I wanted to check is whether I can spot interspecies pairs peat-diving (leaving open the question of whether they actually lay eggs or not). I never expected keeping those eggs: even without hybridation, there is the much simpler question of the 2 spp. using the same spawning ground. The point was to just see how the fish interact, and probably keep them together only for a while, provided they don't suffer too much.

[mk_ultra]

That would be very interesting to see.
Yes, that's right about eco-niche. there are many "niches" outside the realm of local ecology (sounds kinda contradictory, I know). I was being very specific.