Sharks and Skates of Scotland Report: Shagreen skate (Leucoraja fullonica)

An extract from the Sharks and Skates of Scotland Report.

Shagreen skate - Leucoraja fullonica (Linnaeus, 1758) 

Note: An accurate stock assessment has not been conducted due to a lack of long-term standardised abundance data for this species covering the whole stock area in the NE-Atlantic (McCully and Walls 2015), as well as a paucity of data on exploitation rate (ICES 2018). Some confusion/misidentification with larger individuals of small-eyed ray (Raja microocellata), ICES 2024. Suspected misidentification; Scottish landings of white skate (Rostroraja alba) may refer to shagreen skate (Leucoraja fullonica) in some cases (McCully-Phillips and Walls 2015).  

Population status

Scotland and Northeast Atlantic: Stable. The trend analysis of the North Atlantic modelled biomass for 1997–2021 (24 years) revealed annual rates of increase of 0.23%, with the highest probability (36%) of no significant reductions in population over the past three generation lengths (36 years), though it was also quite probable that the species had exhibited a decline (Finucci et al., 2025). In the Mediterranean Sea, the shagreen skate is very scarce and is believed to have undergone a significant decline (Follesa et al., 2019; Geraci et al., 2021; Chatzispyrou and Koutsikopoulos, 2023; Finucci et al., 2025).

Global: Decreasing. Due to uncertain abundance trends in the North Atlantic, decreasing trends in the Mediterranean Sea, and high distribution overlap with intensive fishing pressure, a global population reduction of 30–49% was estimated over three generation lengths (36 years) based on abundance data and actual levels of exploitation (Finucci et al., 2025). 

Conservation listings

Range and distribution 

Shagreen skate are found in the Northeast Atlantic and the Mediterranean, and it is suspected that the populations are poorly connected (McCully-Phillips and Walls, 2015). The skate’s distribution in the Atlantic stretches from Madeira and northern Morocco up to Iceland, the Faeroes and around Norway, including the Skagerrak. Specifically around the British Isles, survey data from the 1960s to mid-2000’s indicate that it was absent from shallow waters of England and Wales, and catches were restricted to the northern North Sea (around the Shetland Isles) and Celtic Seas at depths of 90-424 m, with maximum catch rates of 7 individuals per hour (Daan et al., 2005; Ellis et al., 2005). Low numbers have also been recorded at Rockall Bank (McCully-Phillips and Walls, 2015). Historically, this species may have been more widely distributed along the continental shelf in the Northeast Atlantic, and its range is likely now restricted to deeper waters (McCully-Phillips and Walls, 2015). In recent Scottish surveys, catches have mostly been deeper than 200 m.

Habitat 

In the Northeast Atlantic, this offshore species is most often found on the outer continental shelf at a depth of 30 to 600 m, but predominantly around 200 m (Last et al., 2016, Ebert and Dando 2021) from Murmansk (Russia), Iceland and Norway in the north to Morocco in the south, and the Mediterranean Sea (Last et al., 2016).

Biology and Ecology

Shagreen skate have a relatively large body size, with a recorded maximum size of 100-110 cm TL. Survey data from the Celtic Seas and North Sea (1992 - 2011) recorded males measuring from 21-96 cm (TL) and females measuring 24-70 cm TL, the vast majority of which were immature (McCully et al., 2012). The species are oviparous, laying paired eggs (Dulvy and Reynolds 1997) that measure 7.5-9.9 cm long to 4.5-9.9 cm wide and are deposited on sandy or muddy flats (Breder and Rosen 1996). Little else is known about the biology and reproduction of this species (Finucci et al., 2025).  

Human interactions 

There is no targeted fishery for Shagreen skate in Scottish waters, but their relatively large body size makes them vulnerable to exploitation, and they are usually taken as bycatch of trawl and gillnet fisheries, including mixed demersal fisheries targeting hake, anglerfish, and megrim (ICES 2024). The species can be a relatively important bycatch in the southwestern Celtic Sea and in some deep-water fisheries operating on continental slopes and offshore banks (ICES 2018). 

Shagreen skate are included in the group of ‘other skates and rays’ in the ICES assessments for the North Sea, with ICES unable to provide any advice for the period 2024-2027 due to the lack of sufficient survey and catch data (ICES, 2023). For West of Scotland, southern Celtic Seas, and English Channel, ICES advised that when the precautionary approach is applied, landings should be no more than 134 tonnes in each of the years 2025–2028 (ICES, 2024).