Barbus arcislongae

Barbus arcislongae, a Lake Malawi endemic, is perhaps the least known of the lake's small barb species. It was described by Keilhack (1908) from three specimens collected at the north end of the lake, and was originally called Barbus trispilopleura arcislongae but later recognized as a full species by Boulenger. There are at least two additional specimens in Belgium's Musée royal de l'Afrique Centrale from 4 km north of "la baie de Nego, lac Nyassa," Mozambique, collected in 1979 (FishBase). (No such locality as Nego is listed for Mozambique on the GEOnet Names Server; possibly this is the same as Ngôo or Ngoo, a village on a small bay on the central Mozambique coast?)

In the Malawi barb fauna, B. arcislongae is characterized by having all of the following:

exposed margins of the scales with the striae (streaks) radiating fanwise rather than being parallel (this places it in the "small barb" group);
last simple (unbranched) dorsal fin ray not, or only feebly, enlarged and not serrated;
two barbels on each side of the head;
three large spots on the body, two of which are above the lateral line, the third on the caudal peduncle; and
31-33 scales in the lateral line (Jackson, 1961: 595).

B. arcislongae can be distinguished from the similar B. trimaculatus, which may have one, two, or three spots, in that B. trimaculatus has the last simple ray of the dorsal fin enlarged and bony (but again not serrated).

No bionomic details or even a maximum size is given in the literature available to me (including the unusually sparse species account at FishBase), and no illustration of the species is at hand.

The Cichlid Fishes of Lake Malawi, Africa: MalawiCichlids.com