TEM of microsporidian infection beneath the cuticle, xenoma structure and merogonial replication of Desmozoon lepeophtherii n. gen., n. sp. a) The microsporidian infection (mi) is found beneath the cuticle (cu) and originates from the innermost portion of the epidermal tissue layer (el). b) A small xenoma contains mature spores (s) and reveals that the host nucleus (white asterisks) is not infected by the microsporidian but is grossly hypertrophic and has numerous branches and folds. c) An early meront stage with a single nucleus in diplokaryotic formation (di). d) A divisional meront showing cytoplasmic constrictions (black arrows), that contains two nuclei in diplokaryotic arrangement (di). e) A large divisional merogonial plasmodium (pl) situated next to a host cell nucleus (hn), black arrows indicate nuclear activity associated with nuclear dissociation of the diplokaryon in neighbouring meronts. f) An enlarged view of the same plasmodium, with single unpaired nuclei (sn), undergoing division via plasmotomy (black arrows). White arrows indicate electron-dense laminate bodies lying on the nuclear membrane indicating recent nuclear activity due to nuclear dissociation of the diplokaryotic arrangement. Scale bars a-b 5 μm, c-f 2 μm.