Wittmannia antarctica N. G., N. Sp. (Nosematidae), a New Hyperparasite in the Antarctic Dicyemid Mesozoan Kantharella antarctica

• Published in: The Journal of Eukaryotic Microbiology
• Main Author: CZAKER, RENATE
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: Antarctic; The Antarctic; Weddell; Weddell Sea; Antarc*; Antarctica
• Online Access: http://dx.doi.org/10.1111/j.1550-7408.1997.tb05721.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1550-7408.1997.tb05721.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1550-7408.1997.tb05721.x

ABSTRACT. Collections of the dicyemid mesozoan Kantharella antarctica were made in the Weddell Sea during the Antarctic Expedition of the research vessel RV Polarstern in 1990 and 1991. A diplokaryotic microsporidian was found infecting all nematogens from all the samples taken in both years. The infected cells contained all developmental stages. Merogony initially was monokaryotic and spoorogony of diplokaryotic sporonts was by multiple fission. The stained ovoidal spores measured between 4.3‐6 μm X 1.7‐2.3 μm. The ultrastructural findings come from 11 specimens of Kantharella antarctica that were cut in serial sections. All developmental stages were noteworthy because of the myelinosomes situated adjacent to each diplokaryon. Similarly conspicuous were some organelles in the spore: a prominent, extraordinarily electron dense anterior portion of the polaroplast and the posterior vacuole. The isofilar polar filament with a diameter of about 115 nm showed 9‐11 coils. The great number of empty spore cases together with an extruded polar filament are indicative of an autoinfection. Though these characteristics resemble in part those of the genus Nosema from the family Nosematidae, the species in Kantharella antarctica differs from the former by its unusual development, life cycle and unusual host. Thus, this new species has been placed in a new genus and the name Wittmannia antarctica proposed.