Nagurus cristatus (Dollfus, 1889)
Status:
GB IUCN status: Not applicable (non-native)
ID Difficulty
Identification
Nagurus cristatus is a medium sized species (to 10 mm body length) with a yellowish and brownish longitudinal pattern on the dorsal surface. It has the general appearance of a slender immature Porcellio scaber, but differs in the shape of the head lobes, notably the medial lobe which bears a characteristic prominent central notch. It also has five pairs of pleopodal lungs. Only females are known (it is believed to be parthenogentic).
A brief description of this species, with figures, is given by Gregory (2014).
Distribution and Habitat
There are old records from Northumberland, but the only recent records for Nagurus cristatus are from Eden Project (Rainforest Biome), Cornwall between 2004 and 2010 and still present in 2020 and 2024 (Gregory, 2014; Gregory, 2025). In 2017 a population was discovered at Birmingham Botanic Gardens (Gregory & Lugg, 2020). This species is very likely to be present in other tropical glasshouses throughout Britain and Ireland.
Specimens have been hand sorted or sieved from deep accumulations of leaf litter inside tropical glasshouses.
It is very widely distributed throughout the tropics and, as an introduction, inside glasshouses elsewhere.
References
Gregory, S.J. (2025) 15 years on: An update to Woodlice and Waterlice in Britain and Ireland, part 2 ~ Non-native species, not yet naturalised. Bulletin of the British Myriapod and Isopod Group, 37: 7-25.
Gregory, S.J. & Lugg, K. (2020) Some recent observations of woodlice (Isopoda: Oniscidea), millipedes (Diplopoda) and centipedes (Chilopoda) from artificially heated glasshouses. Bulletin of the British Myriapod and Isopod Group, 32: 35-43.
Gregory, S. (2014) Woodlice (Isopoda: Oniscidea) from Eden Project, Cornwall, with descriptions of species new to Britain, and poorly known British species. Bulletin of the British Myriapod & Isopod Group 27: 3-26.
Links
World List of Marine, Freshwater and Terrestrial Isopod Crustaceans: https://www.marinespecies.org/isopoda/aphia.php?p=taxdetails&id=261350
BRC code
83
idBmigTaxa
Cru_1522