Anguilliform body (Ref. 51442). Jawless with a round sucker-like mouth and sharp teeth arranged in many consecutive circular rows (Ref. 88171). Presence of 7 branchial openings behind the eye (Ref. 51442, 88171). It lacks paired fins (Ref. 88171). Number of myomeres: 67-74 (Ref. 6258). Olive or brown-yellow on the dorsal and lateral part of the body, with black marblings; becomes lighter ventrally (Ref. 35388, 51442, 58137).
- Maitland, P.S. and R.N. Campbell 1992 Freshwater fishes of the British Isles. HarperCollins Publishers, London.368 p. (Ref. 6258) http://www.fishbase.org/references/FBRefSummary.php?id=6258&speccode=4472