Undulate ray

How it lives

It lays eggs. The egg cases, often called mermaid's purses, are oblong capsules with stiff pointed horns at the corners, about 7 to 9 cm long without the horns. Laying runs from March to September, and about 30 eggs a year are reported for one female. Females mature at about age 9 and males at about age 8. Size at maturity is about 80 to 85 cm, and about 84 cm for females in Portuguese waters. It lives on sandy, muddy or gravelly bottoms, mostly at 50 to 200 m according to Wikipedia. A 2012 review says it is most abundant in coastal waters shallower than 50 m, often near large estuaries, rias and bays. FishBase gives 20 to 200 m. Lifespan is not given in the sources I opened.

Where it goes

Its distribution is patchy, with sites of local abundance such as the central English Channel and the coasts of Ireland, France, Spain and Portugal. I did not find tracking data in the sources I opened. A 2026 modelling study projects that suitable habitat could shrink and shift south under one climate scenario, which is a projection and not an observation.

We only draw a journey on the map when scientists have tracked it or clearly documented it. For this animal we have not found one yet.

Populations

IUCN Near Threatened; FishBase gives the assessment date as 15 April 2023. A 2012 review says an earlier assessment listed it as Endangered, because of its large size, patchy distribution and risk of local depletion. Since 2009 the European Union has prohibited commercial fisheries from landing it. It occurs from southern Ireland and England to Senegal and in the western Mediterranean, and the south coast of the British Isles is the northern edge of its range. It can be locally abundant, and in places it is the dominant skate. I did not find a total population count.