Sphaerichthys spp Chocolate Gouramis... sel.  – 08/26/09
Hi Bob,
<Hello Nathan, Neale standing in for Bob.>
A few years ago I kept chocolate Gourami and had reasonably good success in keeping them alive.
<One of the few. While there's a UK association devoted to these fish and their relatives, the Anabantoid Association of Great Britain, there's nothing comparable in the US so far as I know.>
Since that time I haven't had any luck finding more of them. Now I live in north FL and local aqua shops just look at me like 'what is that' when I mention chocolates.
<They aren't widely traded in the US or indeed the UK because of their poor survival record. That said, some shops do get them, and provided you can offer the very soft, very acidic water the various Sphaerichthys species can be kept successfully. The problem is, as I'm sure you know, that at any pH high enough for biological filtration to work, the lack of acidity allows bacteria to survive and overwhelm these blackwater fish. So you need to use zeolite to chemically filter the water rather than a biological filter. When housed in most retail aquaria, these fish are exposed to pathogens and don't last long.>
Do you have a reliable source for this fish that you'd share, that is if you don't sell them yourself ?
<One store in Florida that impressed me was Aqualand Aquarium in Stuart; the time I visited they had a good selection of unusual fish. Definitely worth a visit. Otherwise, contacting other advanced labyrinth fish collectors will probably be the way forward.>
Thanks for any help or suggestions.
Nathan
<Cheers, Neale.>

Re: Sphaerichthys spp Chocolate Gouramis – 08/26/09
Thanks, Neale...
<Hello Nathan,>
That was some good advice, I'll try Aqualand. Those years ago that I worked w/ Chocolate Gouramis (over 15 years now) I had to order them from NY then to get any quantity. Of course, you know that of the 100 or so that I ordered almost 1/2 were DOA. Our water here is warm, fairly soft and it can be 'peaty', so that helps.
<The peat may or may not help, but the thing certainly seems to be acidity.>
The zoolite filter is a new item for me as I kept these fish for (genetic) research purposes. The study was of several Anabantid species, Bettas too, any of these 'air breathing' fish were of interest in the degree program I was assigned to work on. I could extract the eggs by manipulating the body of an obviously pregnant chocolate female, but never got the eggs to hatch, or the fish to actually breed bc/ it's so different w/ them vs. regular gouramis, as you know.
<Indeed, and this mouthbrooding behaviour is fairly unusual among labyrinth fish. Apparently evolved multiple times, perhaps under different selection pressures: fast-water Bettas, Pikeheads in acid swamps, and a few Gouramis including the Chocolate Gourami and its relatives in the genus Sphaerichthys.>
When the males died (them more than females) they were dissected. Male testes were almost non-existent looking compared w/ those of other gouramis - I kept Trichogaster, Osphronemus, and some others.
<Animals in acidic habitats have to get by on very little food, given the trivially low levels of productivity in such places. Perhaps the males develop and then degenerate their gonads as required?>
The 'giant' Osphronemus were kept in an outdoor pool w/ the koi we had then. They became so 'tame' we could hand catch them to draw blood for studying ! I can tell you that the genetic chromosome structure of Sphaerichthys is really 'whacked out' when comparing them to that of the other species in the Anabantid family.
<Interesting.>
Most other Anabantids had bet. 36-50 chromosomes, what's normally expected for them, but Chocolates only had between 10-16 chromosomes!
<Bizarre, but reminiscent of at least some Pufferfish, where a similar compact genome has been observed, if I recall correctly. Genomics was never my thing, and by the time I did my PhD, I was firmly into the ecological side of biology.>
With fish, the chromosome # can vary... but the results for chocolates was sort of interesting. It almost seems as if they're going through evolution in reverse and could be the reason for their many challenging peculiarities.
<"Evolution in reverse" is a phrase that should spark lively debate in a coffee room full of biologists!>
They should probably be considered an 'endangered species', not bc/ of what people are doing to them, but bc/ of their own chromosomes are dictating such a narrow niche for their existence.
<Certainly very specialised. A lot of acidic habitat organisms, from fish to Venus' Fly Traps, are having problems because of a combination of limited geographical range and threats to those bogs and marshes where they live.>
Well, I guess you didn't ask for all of that.
<Always nice to learn something.>
So, I'll be trying to find someone who could help me purchase some of the 'little guys' just to keep for 'old times sake'. Guess I have a 'soft spot' for them after all.
<Oh, they have their fans. A related species, Sphaerichthys vaillanti, has been making the rounds in the UK, though along with Ctenops nobilis, it's one of the tougher labyrinth fish to keep successfully. Anyway, these fish are in the trade, and with luck, you should be able to get hold of some.>
Cheers, Nathan
<Good luck, Neale.>