Involvement of aurantiactinomyxon in the life cycle of Thelohanellus testudineus (Cnidaria: Myxosporea) from allogynogenetic gibel carp Carassius auratus gibelio, with morphological, ultrastructural, and molecular analysis

• Published in: Parasitology research (1987) 2017-09, Vol.116 (9), p.2449-2456
• Main Authors: Zhao, Dan Dan, Zhai, Yan Hua, Liu, Yang, Wang, Si Jia, Gu, Ze Mao
• Format: Article
• Language: English
• Subjects: Animals; Arguloida - parasitology; Biomedical and Life Sciences; Biomedicine; Carps; China; Developmental stages; DNA, Ribosomal - genetics; Fish; Fish Diseases - parasitology; Fish ponds; Germ cells; Goldfish - parasitology; Health aspects; Immunology; Life Cycle Stages; Life cycles; Medical Microbiology; Microbiology; Myxozoa - classification; Myxozoa - genetics; Myxozoa - isolation & purification; Myxozoans; Nucleotide sequence; Oligochaeta; Original Paper; Phylogeny; Ponds; Ribosomal DNA; RNA, Ribosomal, 18S - genetics
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-017-5547-2

During the investigation of actinosporean fauna diversity from commercial fish ponds in Hubei Province, China, a novel aurantiactinomyxon type was found from Branchiura sowerbyi . Spore body of the aurantiactinomyxon was ellipsoidal in side view and triangular in apical view, 15.5 ± 0.5 (14.5–16.4) μm in diameter; three leaf-like caudal processes were approximately equal, measuring 13.2 ± 0.9 (11.5–16.2) μm long and 7.4 ± 0.4 (6.7–8.0) μm wide at the base; three polar capsules were located at the apex of spore body, globular in apical view, 2.2 ± 0.1 (2.0–2.3) μm in diameter, and pyriform in side view, 2.5 ± 0.2 (2.3–2.9) μm in length and 2.0 ± 0.2 (1.8–2.4) μm in width; a total of 32 germ cells were observed within the sporoplasm. Ultrastructural analysis showed that the development was asynchronous between pansporocysts but synchronous within a pansporocyst. The formation of sporoblast and the development of sporogonic stage were also described and discussed. The 18S ribosomal DNA sequences of the current aurantiactinomyxon type corresponded to that of a previously reported Thelohanellus testudineus , suggesting that the newly identified aurantiactinomyxon type is the actinosporean stage in the life cycle of T. testudineus .