gephyra vs agassizii females

[HaakonH]

Apistogramma gephya wild Manaus. Sounds exciting right? I received 30 of them. There sure are some nice males among them, with yellow cheeks. However, I can see a specimen or two of what seems to be A.agassizii "Netz", and also some males with no yellow on their cheeks. These could of course be other gephyra forms, but anyhow - there are many females in the batch too. But if there are multiple species/forms, I'm in for some trouble! Is there a way to tell them apart, or must I simply wait for the males to choose their females?

Haakon

 

[Mike Wise]

Letting the females choose the male is the best way. Just put a couple of A. gephyra males in with a group of females. They will sort themselves out. Otherwise they can be differentiated by gephyra females being (very) slightly more slender and having fewer rows of scales on the abdomen (not easy).

 

[Melanochromis]

Sorting very similar female fish would give me a headache. Unfortunately, I might need to do exactly the same too, as some of the wild fish I posted the other day have turned out to be very, very similar to gephyra. Please let me know which method you decide to use and how it goes.

 

[HaakonH]

I have now read closely in my books (Koslowski, Linke & Staeck, Römer), and found some very useful information, especially from Koslowski ("Die Buntbarsche Amerikas Band 2, Apistogramma & CO."). Apparently gephyra can show 2 lateral spots in certain moods, which is definately the case with most of the fish in the batch I received. I'm under the impression that this trait is not common with agassizii.

So based on this I now have a group of 2 males and 5 females at home, settling in. Photos will follow, but some good photos showing the double-spot trait can be seen here:

http://www.dcg-online.de/encyclopedia/apistogramma-gephyra/

Haakon

 

[Tom C]

.....Apparently gephyra can show 2 lateral spots in certain moods, which is definately the case with most of the fish in the batch I received. I'm under the impression that this trait is not common with agassizii...

I wouldn't rely on the two spots alone, Haakon. This is a A. agassizii I collected in the Rio Tahuayo-drainage in 2011:

and the female sometimes looks like this (she often shows only one spot on the other side!):

 

[HaakonH]

Thanks, Tom yes, I aggree it's not 100% accurate to rely on this alone. However, the black markings are indeed a way to separate gephyra and agassizii. According to Koslowski, gephyra shows a more defined dark part of the lateral band in the part between the main lateral spot and the gill. This short part of the lateral band often begins with what looks like a second lateral spot. At least in the fish you show here, the second lateral spot is on the opposite side of the main spot. In some agassizii this feature is likely to occur. In a group of fish consisting of mostly gephyra males, and where the majority of what seems to be females do show double spots, it's at least very likely that they are gephyra females. But yes, point taken

Haakon