Grenadiers — Macrouridae

Despite their freakish appearance, this group of deep-sea fishes is closely allied to the cods. However, there are many features that readily distinguish the two families. Grenadiers have large eyes and a body that gradually tapers from the first dorsal fin to form a long, sharp point. It is this long, narrow rear end that gives grenadiers their alternate common name, rattails. The second dorsal fin and the anal fins run along the length of this "tail". The first dorsal fin does not have many rays, only 7–14, and stands upright, although it does not contain true spines. The grenadier's head is also striking, bearing two large eyes and a snout that is used to dig in the sediment for food. Small teeth line the jaws and some species possess a light organ on the belly that houses luminescent bacteria.

Most grenadiers are bottom dwellers, although some inhabit the open water. They are found at depths between 200 and 2000 m in oceans worldwide – from pole to pole. These are the most common of fishes on the continental slopes and were once fished commercially. Interestingly, the males of some species are able to produce sound by contracting muscles against their swim bladder.

The russet grenadier, Nematonurus armatus, occurs in the depths of oceans throughout the world and might be found in the Arctic as well, but there are no confirmed reports of this. The marlin-spike, Nezumia bairdi, is another grenadier for which it is uncertain whether its range includes the Arctic.

Four species of grenadiers are known to occur in the Arctic:

Günther's grenadier (Coryphaenoides guentheri)
rock grenadier (Coryphaenoides rupestris)
roughhead grenadier (Macrourus berglax)
smooth grenadier (Nezumia aequalis)