Eel ID - Palmiarnia Gliwice

Not an eel, but a spiny eel (which aren't eels despite the name)

My guess would be Mastacembelus ellipsifer, but I am not 100% sure.

@ralph I'm sure that both eels are the same species and I think you are probably correct.

Thank you both! Of couse, I thought spiny eel, sorry. I tried to compare this photo with others and Mastacembelus ellipsifer looked very similar, but I wasn't sure about that, because is quite rare in the zoos according to ZTL (only Leipzig keep them).