Saithe

Pollachius virens is a species of marine fish in the genus Pollachius. Together with P. pollachius, it is generally referred to in the United States as pollock. It is commonly known in Britain as the coalfish, coley, or saithe , and the young fish may also be called podleys in Scotland and northern England. This species can be separated from P. pollachius by looking at the relative lengths of the upper and lower jaws. P. pollachius has a longer underslung lower jaw while P. virens has approximately equal upper and lower jaw lengths. This gives a very different profile to the head. In general, P. pollachius is a brown or golden colour with a dark back while P. virens is bright silver with a very dark green back. P. virens generally appears to have relatively smaller eyes. The lateral line of P. pollachius has a noticeable kink over the pectoral fins while that of P. virens is straighter.

Source: Wikipedia