Undulate Ray - Raja undulata

Status: Endangered … Undulate Ray have 40 - 50 rows of teeth in their upper jaw

Type: Fish

Location: Patchy distribution in the eastern Atlantic, from southern Ireland to the Gulf of Guinea and including areas of the Mediterranean. Northern-most limit is around the southwest and south coasts of the UK.

Size: Can reach a maximum length of 90cm nose to tail

Habitat: Shelf waters to about 200m deep, preferring shallow waters, on sandy and muddy bottoms.

Main Threats:
Undulate ray populations have been decreasing throughout its range since the 1980s, with declines of up to 80% recorded in some areas. Until recently they were targeted for their meat, and are caught in bottom-towed trawl as well as bottom-set gill nets. Like many shark, ray and skate species, they are vulnerable to over-exploitation because they are slow growing, long-lived and have relatively low reproduction rates. In 2009 the EU designated undulate rays as a prohibited species, meaning the EU and third party vessels could no longer target, retain and land undulate rays in north east Atlantic waters.

The main threat to undulate rays is bycatch in mixed fisheries, but they are thought to be quite resilient to capture and release, and so if they are discarded alive, survival is thought to be high. Some UK fishermen are now reporting that the species is making a comeback in some areas, particularly in the English Channel, where it was absent from surveys for several years. Undulate rays are also a popular sport fish with recreational anglers, who usually release any rays they catch.

Undulate rays are considered a special feature for protection in English MCZs, and so far two MCZs have been recommended to protect undulate rays. While Studland Bay was dropped from the Government’s latest public consultation on MCZs (tranche 2), the Offshore Overfalls off Sussex was included in the consultation. Unfortunately the undulate ray was not included as a potential feature for this site as there was not thought to be enough evidence, and the consultation is now asking for any evidence that undulate rays are there.
Undulate rays are fascinating creatures that get their name from the undulating motion of the leading edge of their fins from snout to wing tip. Their band-like markings help them to camouflage themselves against prey and potential predators. Much like sharks, their skeleton is made of cartilage and they also have a surprising number of teeth, with 40-50 rows in the upper jaw. The young feed on a variety of bottom-dwelling creatures, but when mature they specialise on preying on crustaceans – which is where all those rows of teeth come in handy!

Males reach maturity at about 7-8 years old, and females reach maturity at around 9 years. After mating, they lay cased-eggs, known as ‘mermaids purses’ which are dark and oblong with long curved horns at each of the four corners. They hatch after about 3 months, with perfectly formed miniature rays swimming free from their ‘purses’.

Try looking for undulate ray egg cases on the beach if you visit the south coast!

Did you know?

What MCS is doing:

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