Scientific Name: – Pollachius virens
Saithe, Pollachius virens, is a species of marine fish in the Pollachius genus. Together with Pollachius pollachius it is generally referred to in the U.S. as Pollock. Other names include the Boston blues (separate from bluefish), coalfish (or coley) and saithe in the UK.
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 Pollachius 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 larger eyes. The lateral line of P. pollachius has a noticeable kink over the pectoral fins while that of P. virens is straighter. The flesh of Coalfish (P. virens) is darkly coloured (hence the common name) while that of P. pollachius is similar to other members of the Cod family. This dark colour in the fresh uncooked flesh may have led to the undeserved reputation of this fish as poor for eating.
It is common in the northern parts of the Northern Atlantic, including the Bay of Biscay. Adults can grow up to 130 centimetres (51 in) and weigh up to 32 kilograms (71 lb); the species is of great commercial value to fisheries. The fish can be found close to the shore, particularly in rocky areas but larger examples tend to be found around off-shore wrecks and reefs. The largest coalfish ever caught was 50 pounds (23 kg) at Saltstraumen.