Four trematode cercariae from the New Zealand intertidal snail 'Zeacumantus subcarinatus' (Batillariidae)

Abstract

The cercariae and sporocysts (or rediae) of four trematode species are described from the intertidal snail 'Zeacumantus subcarinatus': a distome xiphidiocercaria assigned to the genus 'Renicola' (family Renicolidae); a monostome xiphidiocercaria belonging either to the genus 'Microphallus' or 'Megalophallus' (family Microphallidae); a magnacercous cercaria of the genus 'Galactosomum' (family Heterophyidae); and a cercaria of the genus 'Philophthalmus' (family Philophthalmidae). The morphological features of these cercariae are compared to previously described cercariae of the same genera. In addition, since the philophthalmid cercaria encysts readily on artificial substrates in the laboratory, the metacercaria of this species is also described. These cercariae are part of a diverse community of at least six digenean species parasitising the snail 'Z. subcarinatus' that, together, have a major impact on the ecology and evolution of this snail.