Orkney Char

Salvelinus inframundus has the following characteristics which in combination make this taxon different from other "Arctic charr" in Great Britain. It has a relatively shallow body which is less than a fifth of its body length, it has an inferiorly positioned mouth, the pectoral fins are 67–88% the length of its head and there are 8–9 10 soft rays in the dorsal fin with 8–9 soft rays in the anal fin. It has moderately large teeth, 9–11 branchiostegals, 13–14 gill rakers, 188–200 lateral scales and 63–64 vertebrae. Other distinguishing features cited include a blunt snout; steel-grey colour on the sides with a white to pinkish or bright orange belly; there are numerous whitish spots along the flanks, mostly on the upper half of body. The pectoral and anal fins are orange-brown to orange-red while the pelvic fins can be cherry-red, and all have a white leading edge.

This species is known only from specimens fished in Heldale Water, Hoy Island, Orkney, Scotland. It has not been recorded since 1908, so in 2024 it was listed as extinct in the IUCN Red List. This has been suggested to be due to engineering works in the late 19th century which disrupted the species ability to spawn, and competition with non-native Brown trout introduced during the early 20th century. However, the same or a very similar fish has been observed in Loch Mealt, on the Isle of Skye.