Can older Panduro/Nijsseni males have extended dorsal fin?

[Melanochromis]

I saw a very beautiful pair of Apistogramma labeled as "Panduro" at a fish shop yesterday. The male, who is very large and seems a bit old, has an extended dorsal fin.

Unfortunately, I didn't bring my camera with me. But I found an Internet picture that looks similar to the fish (the bluish/yellowish coloration is similar, no clear botch at the tail at the time of observing, the dorsal fin is somewhat developed).

Please have a look at this picture and imagine a similar fish with a slightly higher dorsal fin.
http://akvaforum.no/profile.cfm?id=1123&tab=3&image=13524

So my question is that can an older male Panduro, or perhaps Nijsseni, develop an extended dorsal fin?

Or perhaps it is a different fish?

Or perhaps it's a hybrid? With extended dorsal and more yellowish color than a usual Panduro, can be it a hybrid with Inka, which happens to be quite common here?

 

[blueblue]

I have seen and kept male Panduros which develop extended "long" dorsal;
but not Njsseni (Panda).

 

[Mike Wise]

One easy way to differentiate A. nijsseni males from A. panduro males is the form of the dorsal fin. A. nijsseni males have truncate/even dorsals while A. panduro males have slightly serrated dorsals - which can grow slightly longer with age. The fish on the akvaform.no is correctly identified.

 

[Melanochromis]

I see. Thanks to both of you for the clarification. I think this should help.