Actual identity of LG6 / Sturisomatichthys "foerschi"



Since the publication of the first catfish atlas by Evers & Seidel in 2002, an uncommon whiptail species related to Rineloricaria sensu lato is encountered in the trade as LG6 (Loricariidae Genus 6) - former name Sturisomatichthys "foerschi". It has especially large fins and its filamentous extensions as well as the uncommon behaviour in breeding led Evers and Seidel to assume that this species doesn’t belong in a described genus. Covain told me that LG6 would be a species the name of which is long known in the hobby as a phantom. He indicated it is Hemiloricaria parva (Boulenger, 1895).

LG6 / Sturisomatichthys "foerschi"

The only available type material of this species is the lectotype BMNH 1895.5.17.91. So I compared several specimens from different aquarium populations with this type. Even before measuring, it was already recognizable that LG6 and Hemiloricaria parva should be closely related at least. The roundish head shape and the large fins are very unusual for a species of the Rineloricaria group.

So I measured the lectotype of Hemiloricaria parva, 6 specimens of LG6 as well as type material from different Hemiloricaria and Rineloricaria species (H. lanceolata, H. eigenmanni, H. hasemanni, H. jubata, H. magdalenae, H. melini, H. morrowi, H. aurata, H. sp. "Amazonia", R. strigilata, R. misionera). After measuring the first assumption was confirmed. The lectotype of H. parva and all specimen of LG6 show the same identical characteristics. No other described species of Rineloricaria sensu lato features this combination. Next to a very large dorsal fin, the large diameter of the eyes combined with the large interorbital width is characteristic for this species. That leads me to the confirmation that the species known as LG6 is indeed Hemiloricaria parva.

Hemiloricaria parva, Lectotype BMNH 1895.5.17.91

Thanks to all who helped me doing this elaboration! Mark Allen and Karsten Schönherr for the pictures shown here. Rune Birkeland, Ralf Heidemann, Nicole Kriyonas, Ingo Seidel and Karsten Schönherr for pictures of several LG6 specimen. And at last I would like to thank Julian ‘Jools’ Dignal one more time for checking the spelling and Raphael Covain for giving the hint of the identity.