The descriptive text, below the map, is from the Cornish Red Data Book (2009). The map on this web page depicts the organisms distribution and shows the records made pre-2000 and those made since.
Range & Status
Although it is ' essentially a circum-Mediterranean species' (Bratton, 1991), there are 19th century records as far north as York. Recent records are from Devon, Dorset, Cornwall and south Hampshire, with others from Cambridgeshire and Wales.
It was recorded in six 10km squares at the turn of the century (Norman & Scott, 1906); there are no further records (apart from a few without site details) but since 1967 it has been discovered in a further seven, different, 10km squares resulting from a request for records by Matthews (1989). There are at least six post-1980 sites for this species, the most recent being from the Lizard Peninsula in 2002. In Cornwall its decline may not be as marked as elsewhere, although temporary stands of water are declining and at least two of the habitats where it has been found in the past few decades have been destroyed. In Cornwall it has been found in VC1 (SW53*; 61; 62*; 73*, 86*, 87; 94; 95*; 97) and in VC2 (SX03; 04; 05, 06; 07; 08*; 15) - * indicates a pre-1906 record.
Habitat & Ecology
It lives in ' temporary ponds ranging from cart ruts to weedy ponds' and is ' usually in pools receiving regular disturbance by trampling livestock, ploughing or vehicles' (Bratton, 1991).
Drainage, infilling and any change of land use (i.e. removal of livestock from a site) is likely to make the habitat unsuitable.
Any sites should be carefully monitored and active management is often essential. The shallow or weedy stands of water which favour its presence, often dry out for at least one season, but drought-resistant eggs can be produced. One month of immersion can be sufficient for it to complete its life cycle. Detailed information and further references are given in Bratton (1991). Added to Schedule 5 of the Wildlife and Countryside Act (1981) in 1988.
I.J. Bennallick, S. Board, C.N. French, P.A. Gainey, C. Neil, R. Parslow, A. Spalding and P.E. Tompsett. eds. 2009. Red Data Book for Cornwall and the Isles of Scilly. 2nd Edition.Croceago Press.
The Cornish Red Data Book Project was led by the Cornwall and Isles of Scilly Federation for Biological Recorders (CISFBR). The full text and species accounts (minus the maps) are available on the CISFBR website.