Xenomystus nigri

The African knifefish is distinguishable from N. chitala by the absence of a dorsal fin, but resembles it in being a twilight species. Occasionally it emits a groan-like sound from the pneumatic duct, which links the swim bladder to the digestive tube. Size: 10-20 cm

• Tilapia buttikoferi
• Sciaenochromis ahli
• Uaru amphiacanthoides
• Tropheus duboisi
• Brachydanio albolineatus