Male from population with highest recorded % of males in Europe. Flexed penis (1) with longitudinal band of wavy white on grey behind head. Shell height 3.8 mm. September 2012. Llanfihangel, Wales.

SPECIES DESCRIPTION at: 01 Potamopyrgus antipodarum

O.S. map name is Llanfihangel y Traethau, but road signs and study by C. Wallace refer to village as “Ynys”. In 1980, 1981 & 1983 Wallace recorded 16%, 8.5% and 19% males, respectively, at a sharp bend in the A496 where a bridge carries it over the stream that flows alongside Ynys village (sample sizes 331 – 1116). In 2012 twenty specimens were examined by IFS before this male was found. 20% males were found a little upstream in 1983; the highest proportion of males found in Europe.