Achirus Lineatus

[Fella]

Has anyone ever kept these? I got one free today with a new tank (He was being bullied by oscars so I took pity on him, more fool me) and I'm of the understanding these are brackish water fishes?

I'm assuming low SG 1.005?

I'm not sure if I'll keep him yet, There's a chance I'll trade him at a more reputable store.

Any experience with these fish would be greatly appreciated.

 

[nmonks]

See its FishBase entry. Apparently found normally in brackish or hypersaline waters. I'd suggest 1.010 rather than 1.005, but so long as the pH and hardness are high, this may be less of an issue than otherwise. Otherwise as other soles: live food initially, soft substrate, basically hardy once feeding.

Funnily enough, I have a whole long article about "freshwater" soles in the June TFH.

Cheers,

Neale

 

[Fella]

Not too far off then.

Just to double check, here are some very bad, shaky handed photographs of him. Definitely the species I suspected?

Like I say, I'm a fishkeeper not a photographer.

It's a shame I couldn't set a tank aside for him, he's a great looking fish and would make a great oddball.

 

[Fella]

I'm thinking it's maybe not Achirus after all...

 

[nmonks]

Fella --

First thing to do is figure out whether its an Asian Soleidae or an American Achiridae. Generally, as far as aquarium species go, the clue is the tail. Achiridae have large, paddle-like tails so that from above you're looking at one big circle (the body) and another small circle (the tail). With the Soleidae, the tail is small and blends into the body, with only a small gap or narrowing between the edge of the body fins and the tail fin. Typically, from above, Soleidae look like a leaf, with the round end being the head and the tapering end being the back half of the body and the tail.

I think you have a Soleidae, probably Brachirus, possibly B. orientalis or B. panoides.

This is a useful site but it's in Japanese so you'll have to make do with the pictures and bad translations via Babel Fish.

Cheers,

Neale

 

[Fella]

Fella --

First thing to do is figure out whether its an Asian Soleidae or an American Achiridae. Generally, as far as aquarium species go, the clue is the tail. Achiridae have large, paddle-like tails so that from above you're looking at one big circle (the body) and another small circle (the tail). With the Soleidae, the tail is small and blends into the body, with only a small gap or narrowing between the edge of the body fins and the tail fin. Typically, from above, Soleidae look like a leaf, with the round end being the head and the tapering end being the back half of the body and the tail.

I think you have a Soleidae, probably Brachirus, possibly B. orientalis or B. panoides.

This is a useful site but it's in Japanese so you'll have to make do with the pictures and bad translations via Babel Fish.

Cheers,

Neale

Agreed, I had to be quick qith my reply as I was just dashing out, but this fish I have does not have a paddling tail.

It looks to me like this fish out of all the ones I checked on fishbase. With what you know on these fish, what recommendations would you give for looking after them?

Many thanks,

Craig

 

[nmonks]

B. harmandi is considered to be a true freshwater fish, even though it is sometimes found in brackish water. It is unique among the traded soles in having sooty markings on the blind side of the fish (the "underside") particularly towards the tail, so is among the few soles truly easy to identify. See here:

Lookalike species are B. panoides and B. orientalis. B. panoides is sometimes sold as B. pan (a totally different species). Telling them apart is not easy. B. panoides has a tapering body whereas B. orientalis is more oval and the tail fin is a bit more obvious, with a dip between the dorsal/anal fins and the tail fin. B. panoides has a small pectoral fin whereas that on B. orientalis is quite a bit larger. Colour and markings are very similar (i.e., variable).

As far as I can tell, B. orientalis is more brackish to marine (though tolerant of freshwater) whereas B. panoides is a freshwater fish that also lives in brackish.

A default situation would be to keep them at a salinity of SG 1.005 to 1.010. This will do neither species any harm, and will at least give you time to figure out which beast you have. My experience of soles is that they are very hardy, with feeding being the only real challenge. Once feeding, they basically take care of themselves. I never identified my species convincingly, though I suspect it was B. panoides. Unfortunately it died after about six months when I had a massive pH crash, so all I can add from that is that they don't like very acidic water.

Cheers,

Neake

It looks to me like this fish out of all the ones I checked on fishbase. With what you know on these fish, what recommendations would you give for looking after them?

 

[Fella]

Neale,

The image isn't showing up, however, do you mean where the underside is white, with it turning more grey-ish towards the tail? If so, that is concurrent with the fish currently in my tank.

Craig

 

[nmonks]

Yep, that's exactly what I mean. So, you have B. harmandi! Lucky old you... a genuinely freshwater species to play with! The pictures are here:

http/www.geocities.co.jp/AnimalPark-Shir.../haramandi.html

I guess Geocities don't like hot-linking!

Cheers,

Neale

The image isn't showing up, however, do you mean where the underside is white, with it turning more grey-ish towards the tail? If so, that is concurrent with the fish currently in my tank.

 

[Fella]

I caught him on the curve of the glass this morning, I guess he can't grip on the sides!

 

[nmonks]

Yep, that's harmandi. Very nice. Where did you get them?

Here's a useful read, a PDF file on tropical flatfish ecology produced for the Mekong River Commission. It says:

Very little is known about the distribution of individual flatfish species in the Mekong Basin and to what degree they are able to reproduce in freshwater, but some species (for example Euryglossa harmandi) occur in the Mekong and in large tributaries at least 2000 km from the river mouth. It is unlikely that these species have any marine life stage, because, as already mentioned, none of the species are strong swimmers, and they would probably not be able to migrate such long distances

I found another useful web page in Japanese. Again, Babelfish does a good enough translation. The Japanese seem to call freshwater flatfish "mosquito rays", perhaps because they look like rays but eat mosquito larvae?

Cheers,

Neale

 

[Fella]

Yep, that's harmandi. Very nice. Where did you get them?

Here's a useful read, a PDF file on tropical flatfish ecology produced for the Mekong River Commission. It says:

Very little is known about the distribution of individual flatfish species in the Mekong Basin and to what degree they are able to reproduce in freshwater, but some species (for example Euryglossa harmandi) occur in the Mekong and in large tributaries at least 2000 km from the river mouth. It is unlikely that these species have any marine life stage, because, as already mentioned, none of the species are strong swimmers, and they would probably not be able to migrate such long distances

I found another useful web page in Japanese. Again, Babelfish does a good enough translation. The Japanese seem to call freshwater flatfish "mosquito rays", perhaps because they look like rays but eat mosquito larvae?

Cheers,

Neale

I got him from one of the stores I like the least in Nottingham, a back street pet shop which is a place I rarely go to. I went there as I was scoping out prices for a new 10g, and when i bought a tank they had, they offered me the fish free, and as he was being bullied, I thought that turning down the opportunity to rescue him should be one I could take.

Great news that he is totally freshwater though, I thought my chances of that being the case was low, but it seems I got very lucky!

So it seems they'll take bloodworm then? I admit I haven't seen mine eat yet.

I might go back on friday (day after their delivery day) and see if they have any more in. Might be worth getting him a companion.

 

[nmonks]

While it's true the vast majority of flatfish are marine as far as number of species go, the sweeping generalisation that "99% of the ones offered as aquarium fish are brackish/marine" is over-egging the pudding a little bit. Besides B. harmandi, I can think of at least one Achirus, one Synaptura, two Cynoglossus, and one other Brachirus traded at least occasionally that are truly freshwater fish. Having said that, in the US at least the species most often seen is a marine fish, Trinectes maculatus. In the UK, not attempt seems to be made to identify them by importers/retailers, which at least gives you the chance of a freshwater species but doesn't hold out any certainties.

Yes, they will eat bloodworm. Favourite food apparently. Probably have to use live to begin with, and then gradually wean them onto frozen. Livebearer fry might be another option, at least to fatten them up a little. I'm not wild about feeding feeder fish, but these flatfish are so underfed when you buy them, it might be worth the risk.

Important: flatfish are nocturnal to some degree and will only feed at night, at least initially.

They seem indifferent to others of their own kind, but if I was doing a tank for them (and it needn't be very big, a 20 gallon would do), I'd certainly get two or three specimens. Definitely populate the tank with surface-dwellers so there's no competition at feeding time. Neutral to hard, alkaline water probably optimal given this species does sometimes get found in brackish. All flatfish seem sensitive to low oxygen (as is typical with "marine" fish in freshwater habitats).

Cheers,

Neale

Great news that he is totally freshwater though, I thought my chances of that being the case was low, but it seems I got very lucky!

So it seems they'll take bloodworm then? I admit I haven't seen mine eat yet.

I might go back on friday (day after their delivery day) and see if they have any more in. Might be worth getting him a companion.

 

[diburning]

its better to have a sand substrate because these flatfishes can camoflauge. They also Burrow. If you have them in a take with gravel, make sure its round gravel so it doesn't scratch itself. Make sure it isn't colorful gravel either as it will stress your fish out trying to camoflauge to it (usually it will just sit on the glass after a few futile attempts)

 

[Dave Legacy]

Sounds like the LFS in the UK are just crawling with flatfish. I have been looking around the Southern California, USA area for months for a Trinectes maculatus with absolutely no luck. In fact I have only seen some flatfish sold as freshwater flounders once, but I periodically come across a marine species which I believe is Bothus lunatus that gets 14" long.

I consider you guys to be lucky... you have all the brackish fish! Seems most of the LFSs out here don't like to carry brackish fish, the rarer ones at least. One of my T. Jaculatrix Archers got sucked into my canister filter intake and killed and I haven't been able to find a LFS that carries them. All the finds you guys post about makes me want to scoop up my family and move to the UK. =)