title: Ultrastructural comparison of Bonamia spp. (Haplosporidia) infecting ostreid oysters.
abstract: The ultrastructure of Bonamia from Ostrea angasi from Australia, Crassostrea ariakensis from the USA, O. puelchana from Argentina and O. edulis from Spain was compared with described Bonamia spp. All appear conspecific with B. exitiosa. The Bonamia sp. from Chile had similarities to the type B. exitiosa from New Zealand (NZ), but less so than the other forms recognized as B. exitiosa. Two groups of ultrastructural features were identified; those associated with metabolism (mitochondrial profiles, lipid droplets and endoplasmic reticulum), and those associated with haplosporogenesis (Golgi, indentations in the nuclear surface, the putative trans-Golgi network, perinuclear granular material and haplosporosome-like bodies). Metabolic features were regarded as having little taxonomic value, and as the process of haplosporogenesis is not understood, only haplosporosome shape and size may be of taxonomic value. However, the uni-nucleate stages of spore-forming haplosporidians are poorly known and may be confused with Bonamia spp. uni-nucleate stages. The many forms of NZ B. exitiosa have not been observed in other hosts, which may indicate that it has a plastic life cycle. Although there are similarities between NZ B. exitiosa and Chilean Bonamia in the development of a larger uni-nucleate stage and the occurrence of cylindrical confronting cisternae, the clarification of the identity of Chilean Bonamia must await molecular studies.
authors: Investigation and Diagnostic Centre, Biosecurity New Zealand, PO Box 40-742, Upper Hutt 6007, New Zealand.
authors: P M
authors: PM
authors: Hine
authors: R B
authors: RB
authors: Carnegie
authors: M A
authors: MA
authors: Kroeck
authors: A
authors: A
authors: Villalba
authors: M Y
authors: MY
authors: Engelsma
authors: E M
authors: EM
authors: Burreson
mesh_terms: D000818:Animals; D041602:Haplosporida / Q000502:physiology* / Q000648:ultrastructure*; D006790:Host-Parasite Interactions; D010125:Ostreidae / Q000469:parasitology*; D013045:Species Specificity