The Shortjaw Cisco has a thin elliptical body that is covered with large, smooth scales. It is mainly silver in colour, with olive or tan colouring on the back and a white belly. Its small toothless mouth has a bottom jaw that is often shorter than, or even with, the upper jaw. The gill rakers (or comb-like structures on the inner surface of the bony arch supporting the gill) number between 32 and 46, which is typically less than other cisco species.
Cisco species identification is difficult because ciscoes can have different shapes and colours even within the same population. This variation has likely interacted with hybridization, local adaptation, and parallel evolution to produce a confounding assortment of forms and species of ciscoes.
Length: 340 to 420 mm (13.3 to 16.4 in)
Report Shortjaw Cisco sightings to WILDLIFEOBS@gov.nt.ca