title: Structure and development of Sphaerospora elegans Thélohan 1892 (Myxozoa: Myxosporea) in the sticklebacks Gasterosteus aculeatus L. and Pungitius pungitius L. (Gasterosteidae).
abstract: The structure and development of Sphaerospora elegans Thélohan 1892 was studied by light and electron microscopy. Specimens of Gasterosteus aculeatus and Pungitius pungitius were examined from localities in England, Scotland and France. The kidney was found to be the main site of infection in both species, with a frequent co-infection with Myxobilatus gasterostei (Parisi, 1912) Davis, 1944 present in several populations of G. aculeatus. Possible extrasporogonic stages were located in the interstitial haematopoietic tissue of the kidney and in the choroidal rete of the eye. Within renal tubules sporogonic events could be followed and were seen to result in the formation of mature sub-spherical spores 10.2 × 10.1 μm in size, containing 2 almost spherical polar capsules of equal size. Only minor pathological changes were found, even in heavy infections. Relationships with other Sphaerospora spp. and PKX cells are discussed.
authors.affiliation: Ministry of Agriculture, Fisheries and Food, Fish Diseases Laboratory, Weymouth, Dorset, UK.
authors.forename: S W
authors.initials: SW
authors.lastname: Feist
authors.forename: S
authors.initials: S
authors.lastname: Chilmonczyk
authors.forename: A W
authors.initials: AW
authors.lastname: Pike