The gut microbiota of Cystidicola farionis parasitizing the swim bladder of the nosed charr morph Salvelinus malma complex in Lake Kronotskoe (Kamchatka, Russia)

Abstract

Using the approach of sequencing the V3–V4 region of the 16S rRNA gene, we have analyzed the bacterial diversity associated with the gut and “body” (other parts of nematode after dissection: cuticle, epidermis and longitudinal muscles, etc) of Cystidicola farionis parasitizing the swim bladder of different morphotypes of the nosed charr. Comparisons of the gut microbiota of nematodes with their “body” has revealed that the associated microbiota are closely related to each other. Taxonomic analysis indicated that the relative abundances of the dominant nematode-associated bacteria varied with individual fish. The common dominant microbiota of the gut and “body” of nematodes were represented by Aeromonas , Pseudomonas , Shewanella , and Yersinia , while the associated microbiota of the swim bladder of the nosed charr was dominated by Acinetobacter , Cetobacterium , Pajaroellobacter , Paracoccus , Pseudomonas , Shewanella . By comparing the associated microbiota of nematode parasitizing the different morphotypes of the nosed charr the difference in richness estimates (number of OTU’s and Chao1) were revealed between the N1g and N2 morphs.

Cystidicola farionis, a Swim Bladder Parasite of European Smelt: Characterization of the Nematode Trehalose Strategy

“…In studied specimens of C. farionis, a lack of variation within the fragment of the 28S rRNA gene was noted. A similar lack of variability in the same part of the 28S rRNA gene was also demonstrated by Kashinskaya et al [ 27 ] in C. farionis from nosed charr ( Salvelinus malma ) in Lake Kronotskoe in Kamchatka, Russia. Moreover, sequences from examined nematodes from European smelt in the Vistula Lagoon form a homogeneous group together with those obtained from parasites from S. schmidti in Russia and S. trutta in Switzerland.…”