Undulate rays: unusual and uncommon

The undulate is one of the less common rays to appear in Britain’s south coast waters. In fact it is by no means abundant anywhere in European seas — but it is the most distinctive of these flat-bodied fishes.

It can be identified straight away by the clear pattern on the top half of its body. The back is yellowish-brown to brown and spattered with dark brown wavy bands, the edges of which are bordered by white and dark brown spots.

undulate ray

Undulate ray distribution Found offshore, off the southern coast of England and Ireland, the undulate ray is an elusive species but it is believed to be commonest around the North African coast and in the western Mediterranean.

British records


This record is for a 21 lb 4oz 8dm (9.652kg) fish taken by Scott Titt, four miles south of St. Aldhelm’s Head, Swanage, Dorset in August 1987.


An undulate ray weighing 21lb 4oz (9.638kg) was caught at St. Catherine’s Breakwater Lighthouse, Jersey, Channel Islands in September 1983 by K. Skinner.

undulate ray 12 lb (5.67kg) taken off the Isle of Wight in the summer of 1992

This splendidly marked undulate ray, displayed by a delighted angler, weighed 12 lb (5.67kg) when it was taken off the Isle of Wight in the summer of 1992.

Look for the dots

Although the undulate is unlikely to be mistaken for any other ray, another fairly similar-looking species often appears in British waters. The small-eyed ray also has wavy bands across its back, but they are creamy white and are not edged with dots.

Like all rays, the undulate is adapted for life on the sea bed. Its flat body enables it to lie semi-submerged in the sand – concealing itself from both predators and prey.

Like the roker and other common British species, it is a short-snouted ray but it differs from most others because its pectoral fins, or wings, have very rounded tips. The wing outline is curved and undulating -probably the reason for its unusual name.

In common with most rays, the undulate’s skin is rough and its back is covered with coarse prickles, except for the rear margin of the wings.

It has a row of rather large spines down the mid line of its back – from just behind the eyes down to the dorsal fins – and smaller spines scattered on the side of the tail. There are also several spines between the two small dorsal fins on the tail.

It is really one of the most attractively coloured of all rays and particularly well marked specimens are most striking.

Wavy rays are here again

The undulate’s range stretches southwards along the eastern Atlantic coastlines of France, Spain and Portugal to the coast of North Africa, and into the western Mediterranean where it grows slightly larger than in Atlantic waters.

It possibly reaches as far west as the Canary Islands, and often appears around the Channel Islands.

In the British Isles it extends as far north as southern Ireland. It has appeared throughout the English Channel from Cornwall and Devon as far east as Sussex and, very occasionally, off Kent and in the extreme southern North Sea.

Living mostly over sandy bottoms, in some areas (off the Sussex coast, for instance) the undulate can be quite numerous, presumably where the sand is of a particularly suitable texture.

Although it ventures inshore, it is seldom found in water less than 35m (115ft) deep. Exceptionally it has been caught by boat anglers fishing at depths of 100m (330ft).

Unknown depths

Because of its comparative rarity the undulate ray’s life cycle has not been studied in any depth. It is known to eat bottom-living fishes, including flatfish such as plaice and dab, and gobies and possibly herrings as well. Squid and crustaceans also form quite a large part of its diet. It is probably a generalized feeder, taking any soft-bodied food to be found near the sea bed.

Like many rays, the undulate is not particularly agile or fast. It catches its prey by smothering the fish with its wings, then kills the unfortunate victim by crushing it with its strong teeth.

The undulate breeds in the late summer in British seas, but early in the summer in the Mediterranean.

The eggs are laid in orange-brown sacs, or ‘mermaid’s purses’ as they are more commonly known. The purses, 8-9cm (3-3/4m) long (excluding the horns at the corners), have one side covered with a dense mat of bristly fibres — possibly designed to catch and hold fast on seaweed. is choked by thick blanket weed in summer, which makes the stretch virtually unfishable. So it’s really a winter venue – when the roach are in their prime.

It’s not the easiest of waters. Mick has only taken about a dozen fish from it over the magical two pound (0.9kg) barrier during the last eight years. “There are quite a lot of fish between one and two pounds but I have seen three pounders spawning on the gravels in summer.”