Chirocephalus diaphanus

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.

Regional Distribution

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).

Threats

Drainage, infilling and any change of land use (i.e. removal of livestock from a site) is likely to make the habitat unsuitable.

Conservation

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.