In our newsletter from the last weekend we mentioned that besides the three described species of Retroculus also an undescribed one exists. Sadly we overlooked that the undescribed has been in fact described in June this year: Retroculus acherontos from the Rio Tocantins. The species is distinguished from all other species of Retroculus by a hump on the fronthead (visible in specimens from 12-13 cm length) and the fact the the dark spot in the soft part of the dorsal fin is situated in the median part of that fin and not, like in all other Retroculus, near the back. Additional species differences are not visible in live fish.
As far as we know this beautiful fish has not been imported yet. Pictures of freshly captured, living fish can bee seen in the most current issue of Amazonas Magazine (No 61 for September/October 2015).
Literatur: Landim, M. I. , C. R. Moreira and C. A.
Figueiredo (2015): Retroculus acherontos, a new species of cichlid fish
(Teleostei) from the Rio Tocantins basin. Zootaxa 3973 (no. 2): 369-380
Text: Frank Schäfer
