My bet is that it's K. guianensis... which is available as a result of a Jeff Rapps export from Suriname a few years ago. Prior there weren't any of those kinda Krobia floating around (at least as far as I know).
It's also a pretty safe bet that the K. guianensis (or the like) were all collected in one area (vs. far flung places all over Suriname), as they were included to fill out boxes of Crenicichla that the guy Jeff had collect was focused on...
Matt
To my knowledge there have been no exports from French Guiana (where K. itanyi) is found.That said, whether scientists determine that the various Krobia that look like K. guianensis are actually K. guianensis or "new" species (e.g. K. pataroensis, K. petitella, sp. red eyes, etc.), is up to people counting scales and blotches (from CRC):
Diagnosis: Krobia petitella can be distinguished from described Krobia species by tubed scales of the upper lateral line extending caudally into a line bisecting the lateral band blotches posterior to the mid-lateral spot (vs. ULL tubed scales lying dorsal to lateral band). K. petitella can be further diagnosed by the anterior lateral band spots lying immediately ventral to the upper lateral line, instead of being separated from the upper lateral line by a complete row of scales in all other described species. Krobia petitella also has a unique combination of six distinct vertical bars and four lateral band spots (vs. K. itanyi 5 bars/3 or 4 spots, K. guianensis 5/5, K. xinguensis 7/6, Aequidens potaroensis 6/6, A. paloemeuensis 5/5). K. petitella is further distinguished from K. guianensis and K. itanyi and from Aequidens potaroensis and A. paloemeuensis by separation of the caudal spot on the dorsal caudal fin lobe from the lower lateral line by one scale length (vs. no separation). Krobia petitella can be distinguished from K. guianensis, Aequidens potaroensis and A. paloemeuensis by lacking a lateral band spot in bar 2 (vs. spot in bar 2 in K. guianensis, A. potaroensis and A. paloemeuensis). Krobia petitella can be distinguished from K. guianensis by the presence of two distinct interorbital stripes and a prominent preorbital stripe (vs. absence of interorbital and preorbital stripes). Krobia petitella can be further distinguished from K. guianensis by a significantly longer snout and longer fins on average. Krobia petitella can be further distinguished from K. itanyi by having the lateral band extending to the posterior base of the dorsal fin (vs. ending well before the base of the dorsal fin). Krobia petitella can be further distinguished from K. xinguensis by lacking anterolateral spots on the lower jaw and a lateral band blotch located in the second vertical bar as seen in K. xinguensis (spot in bar 2 also occurs in K. guianensis]) in addition to having a longer snout and shallower body than K. xinguensis on average. Krobia petitella is distinguished from Aequidens potaroensis and A. paloemeuensis by lacking lateral band spots on the caudal peduncle. K. petitella can further be distinguished from A. potaroensis by having a significantly deeper head, body and caudal peduncle as well as longer fins on average. (From Steele et al, 2013).
