Greater Pipefish

Greater Pipefish

  • Scientific name: Syngnathus acus
  • Size: Up to 18 inches in length and 5oz in weight
  • UK minimum size: N/a
  • UK shore caught record: 113 grams
  • IUCN Status: NE (Not Evaluated)
  • Distribution: Fairly widespread along the western coast of Britain and all around Ireland. Less common along the eastern coasts of England and Scotland.
  • Feeds on: Very small crustaceans, copepods and planktonic sea creatures.
  • Description: Extremely long and slim body. The snout is very long with the mouth located at the end. A single dorsal fin is present in the middle of the body and pectoral and tail fins are very small. There is a raised crest above the head. The body is rigid and made up of relatively hard scales and ridges which act as a kind of armour to protect the fish. Colour is usually a light brown to yellow/green, with 10 – 20 darker stripes along the length of the body.

The greater pipefish is closely related to seahorse species (they look somewhat like a straightened out seahorse) and are a common species around much of the western coast of Britain and all around the Republic of Ireland, although it is relatively rare along the eastern coasts of England and Scotland. They are also found throughout the Mediterranean and along the eastern and northern coasts of Africa. The greater pipefish is very much a mini-species, growing to a maximum of 18 inches long, although the vast majority are smaller than this, usually failing to grow any bigger than 12 inches and weigh only 2 or 3 ounces.

Habitat, Behaviour and Feeding

Greater pipefish can live in very shallow water and are sometimes found trapped in rockpools at low tide, although they can also live at depths down to around 100 metres. They favour sandy or muddy seabeds and are often found in weed beds or within seagrass beds, and are commonly found in estuaries and sheltered inshore waters. The greater pipefish has a very small mouth which is located at the end of the long snout. They hunt for very small crustaceans such as prawns and sea slaters as well as plaktonic creatures. As their mouth does not open they feed sucking through their snout.

Greater Pipefish in its natural environment

Greater Pipefish in its natural environment.

Greater pipefish are poor swimmers as their very small fins provide weak propulsion and their body is somewhat stiff and rigid meaning they cannot bend very well to create additional movement. This makes them easy prey for predatory fish species. However, their hard scales and ridges work as a kind of armour to provide protection (against smaller, weaker species of fish at least). They can also avoid detection from other species as they are relatively well camouflaged against the seabed and weedy areas where they live.


Pipefish have an interesting reproductive cycle as they conduct a courtship ‘dance’ where the male and female will swim together with their bodies entwined. During or after the courtship the male will fertilise the eggs of the female. In a trait that is shared with seahorses, the female will pass these eggs over to the male who will store them in a special pouch within his body. Once in this pouch the eggs will hatch and the young will emerge from the male.

Commercial Value and Threats

Greater pipefish have zero commercial value. An unknown number of pipefish are killed through being caught as bycatch, although it is not known what effect this has on overall numbers and sustainability. There could be future problems for this species as the weed bed and seagrass habitats of pipefish are being damaged or destroyed through commercial trawling, the development of offshore wind farms and pollution. Despite this, pipefish populations are currently considered to be stable, although they are officially classed as Not Evaluated by the IUCN (International Union for the Conservation of Nature).

Other Species of Pipefish

As well as the greater pipefish there are five other species of pipefish in UK waters.

    • Snake pipefish (Entelurus aequoreus)
    • Nilsson’s pipefish (Syngnathus rostellatus) (Also known as the lesser pipefish)
    • Broad-nosed pipefish (Syngnathus typhle) (Also known as the deep-snouted pipefish)
    • Worm pipefish (Nerophis lumbriciformis)
    • Straightnose pipefish (Nerophis ophidion)

Differences between the species are very slight and most people outside of university marine biology departments would struggle to tell the difference between the different species of British pipefish.

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