snails became infected in spring and summer. The resultant sporocysts were producing infective metacercariae in the following spring but then died in late summer. The lifetime of the adult stage in its bird host is believed to be of the order of weeks or months. Behaviour of the broodsacs and infected snails The pulsations of the broodsacs typically vary from 40 to 75 times a minute depending on temperature, but they cease in the dark. The parasite manipulates the snail host's behaviour in a way likely to make it more conspicuous to birds. In one study of Succinea putris hosts, infected snails stayed in better lit places for longer, sat on higher vegetation, and were more mobile. Whereas 53% of infected snails remained fully exposed for the 45 minutes of the observation period, the figure was only 28% for the controls (nearby snails without Leucochloridium broodsacs). Infected snails may survive for at least a year and continue to be able to use the eyes on the ends of their tentacles. Although snails infected by other Leucochloridium species are reported to continue to reproduce, snails infected by L. paradoxum often show a reduction of the sexual organs. The appearance and behaviour of the sporocysts is a case of aggressive mimicry, where the parasite vaguely resembles the food of the host, thereby gaining the parasite entry into the host's body by being eaten. This is unlike most other cases of aggressive mimicry, in which the mimic eats the duped animal. Taxonomy In older literature, L. paradoxum may be referred to as L. macrostomum, derived from Rudolphi's 1803 description of Fasciola distomum, which he later renamed Distomum macrostomum. Subsequently it was shown that L. paradoxum is a different species; Rudolphi's species is now in the genus Urogonimus. Leucochloridium heckerti Kagan, 1951 is also considered a synonym of L. paradoxum. Identification The easiest way to differentiate between Leucochloridium species is from the appearance of the broodsacs in the tentacle of the host snail. Leucochloridium paradoxum exhibits broodsacs that have green bands with dark brown and black spots, and with a dark-brown or reddish-brown tip. Nowadays this method of identification may be supported with ribosomal DNA sequences. A snail may be simultaneously infected by more than one species of Leucochloridium. The adults, found in the cloaca of birds, are less well known, so that distinguishing the species is less straightforward. Habitat Leucochlordium paradoxum is found