Need Help Id'ing Two Halfbeaks

[Darkmoon Bettas]

I've pored over photos, read all the guides, and I still can't figure these guys out.

First fish were sold to me as Nomorhamphus ebrardtii, but as they matured developed a very thin black edging on the fins that ebrardtii aren't supposed to have--but the beak doesn't look right for a liemi, and most liemi's I've seen have a lot MORE black than this pair. Any thoughts on what they might be, specieswise (or do they look like a hybrid?)

Female, body and head shots:

Male, body and head shots:

These little guys I got at a LFS just labled as "metallic halfbeaks" and they didn't know a thing about them, even how to sex them, so they had no info for me. I know they're a Dermogenys species, but can't clearly tell if they're pusilla or sumatrana. They're SO metallic and bright they're blasted hard to photograph. All three are of the single male, the females look the same, except lacking color in unpaired fins.

I'm still fairly new to halfbeaks--these guys and a reverse trio of genuine ebrardtii (in a seperate tank, they haven't mixed with the mystery norms)--are the first ones I've ever been able to get my hands on, so some help figuring the little critters out would be much appreciated.

 

[nmonks]

Hello --

The little Dermogenys is, I think, Dermogenys sumatrana. As you realise, that species and D. pusilla are very similar. Supposedly, the way you tell them apart is where the pelvic fins are. If they are halfway between the pectorals and the anal, it's D. pusilla; if the pelvic fins are closer to the anal fin, it's D. sumatrana. Beyond that, colouration seems to be very similar.

There are some other species imported from time to time, and I can't find anything that helps identify them. Luckily, all Dermogenys want the same thing: slightly acidic to slight alkaline fresh water, low to moderate hardness, good water current, and a mixed diet including algae-rich flake and some live food such as daphnia or small insects (they love mosqitoes!).

The Nomorhamphus are a little harder. As far as I have experienced, they do not hybridise. I think this is because of the variation in how the embryos develop (see an earlier posting on this topic). Also, most shops only ever sell wild-caught halfbeaks. You are right, they are not N. liemi. I don't think they are N. ebrardtii either -- that species has reddish-orange on the dorsal, anal, and tail fins. My guess is that your fish are Nomorhamphus ravnaki, which have red on the dorsal and tail fins and a yellow tint to the anal fin. Black bands edge the anal fin and the dorsal fin. It isn't commonly traded but I've come across it at least once in batches of Celebes halfbeaks.

Given that it definitely isn't N. ebrardtii, you will do best keeping this fish in soft and acid water, or failing that, alkaline water that isn't too hard. Celebes halfbeaks breed more readily in soft water but they will live just fine in hard water.

Hope this helps,

Neale

 

[Darkmoon Bettas]

Thanks a lot, that's very helpful!

Oddly, the Nomorhamphus are captive-bred and were sold directly to me (online) by their breeder as ebrardtii, which is why they suprised me so much when I realised they definately were NOT as they grew.

On a related note, does the common name/term "wrestling halfbeak" correctly apply to just d. pusilla, or all the dermogenys halfbeaks?

 

[nmonks]

As far as I know, "wrestling halfbeak" is officially just D. pusilla, but since the hobby doesn't distinguish any of the Dermogenys species, it has probably used for all of them at some time or another.

Cheers,

Neale

On a related note, does the common name/term "wrestling halfbeak" correctly apply to just d. pusilla, or all the dermogenys halfbeaks?