Rapier Sturgeon

As its name implies, the Rapier Sturgeon is a fast, slender, deadly fish. While relatively small compared to other sturgeon, it compensates with a lightning fast speed of 82mph. This speed coupled with its razor-sharp bony protrusion on its face means the Rapier Sturgeon can crack the shell of even a Bunker Crab, which they are known to eat on a regular basis. 
While their eyesight is very poor they possess superior olfactory senses as well as clusters of electro-receptors located on top of their dorsal fin. These clusters intercept the low-level electrical fields generated by other creatures and other geo-electric sources. With this combination of sensory systems they can pierce their prey with deadly accuracy.
They primarily reside in the South Harbinger Sea and adjacent waters, however their numbers have been ravaged due to the ecological destruction wrought by the start of the Perennial Wars and the battling over valuable sea-floor mineral deposits.