Dealfish

Dealfish

  • Scientific name: Trachipterus arcticus
  • Also know as: Northern Dealfish, Ribbonfish
  • Size: Usually 3 – 4ft but can reach up to 8ft in length
  • UK minimum size: N/a
  • UK shore caught record: N/a
  • IUCN Status: LC (Least Concern)
  • Distribution: Found predominantly in the North Atlantic Ocean.
  • Feeds on: Believed to feed on small fish and squid.
  • Description: Distinctive looking fish which has an elongated, slender, bright silvery body which is free of scales and sometimes has a number of large black spots present. The dorsal fin is pink to reddish in colour runs the entire length of the body. The tail is very small and also pink/red in colour. No anal fins are present and pectoral fins are very small. Eyes are extremely large and the mouth can be extended outwards when feeding.

The dealfish is an unusual species of fish which, although rare, is found around the UK on a sporadic basis. It is a member of the ribbonfish family, which include nine other species. However, the species featured on this page is the only one found in British waters on anything approaching a regular basis. Many aspects of the behaviour and life cycle of the dealfish remain unknown.

Appearance and Habitat

Dealfish are a striking looking species due to their slender, laterally compressed body which is bright silver in colour and their reddish to pink dorsal fin. They have a widespread distribution being found throughout the North Atlantic Ocean. In European waters this species is found from Greenland and Iceland to Scandinavia and in parts of the northern North Sea, but appears to be absent from the Mediterranean. Dealfish are also found in US and Canadian waters, although these fish may have genetic differences meaning they may be a separate species – see below. Dealfish live in deep water far away from land masses at depths of several hundred metres.

Life Cycle and Feeding

Little is known of the life cycle and breeding patterns of the dealfish. They are thought to spend most of their life as a solitary fish, although they have been known to gather together in large aggregations from time to time. The reason for this is unknown but could be linked to spawning. Despite having a toothless mouth the dealfish is a predator which actively hunts small fish and squid species.

Dealfish washed up on beach.

A dealfish washed up on a beach in the USA.

Dealfish are sometimes found washed up on beaches around the British Isles and elsewhere in the world. It is believed that dealfish which find themselves in shallow waters become confused and disoriented by being out of their deep-water environment and then become caught up by the tide and wind and end up forced onto beaches.

Commercial Value

Dealfish are sometimes caught by commercial vessels trawling for pelagic species such as blue whiting over deep water. However, dealfish have no commercial value and the flesh of this species is, by all accounts, an unpleasant, gelatinous consistency. Any dealfish caught by commercial vessels are likely to be discarded at sea, although some may be retained to be processed into fishmeal.

Other Species of Ribbonfish

The dealfish featured on this page (Trachipterus arcticus) is the only species which is found in British waters, although there are other similar species of ribbonfish found around the world. There is evidence to support that dealfish could be split into two separate species, with dealfish in the Northern Atlantic being different from those found in the Western Atlantic. Some reports recognise this by referring to Northern and Western Dealfish species.

The species known as the red bandfish is also sometimes referred to as a ribbonfish, although it is unrelated to the species featured on this page. Trachipterus arcticus also looks very similar to a much larger and rarer fish which is also a rare visitor to British waters – the giant oarfish, although the species are not closely related.

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