Remarks on the validity of Myxobolus ampullicapsulatus and Myxobolus honghuensis (Myxozoa: Myxosporea) based on SSU rDNA sequences

Abstract

In the present study, we isolated three populations of Myxobolus ampullicapsulatus from the gills of crucian carp, Carassius auratus auratus, two from Yongchuan, Chongqing area and one from Poyang Lake, Jiangxi area, China, sequenced their complete small subunit ribosome RNA gene, analyzed their genetic distance and gene similarity, and explored their relationship based on Bayesian inference and maximum likelihood analyses of their small subunit ribosomal DNA. The results combined with their morphological characteristics suggest that M. ampullicapsulatus infecting the gills and pharynx of allogynogenetic gibel carp, Carassius auratus gibelio, should be Myxobolus honghuensis. This study highlights the importance of DNA sequence comparisons for distinguishing Myxobolus species and indicates that the intra-species identification for the two Myxobolus species mentioned in the present research should be less than ten variation sites. In morphology, M. honghuensis Liu et al. (2012) parasitic on the gills of C. auratus auratus (goldfish) was collected from Chongqing area, and its mature spore was 16.5–19.5 × 8.5–10.0 μm in size, polar capsule was 7.0–10.0 × 2.5–4.0 μm in size, and polar filament had 9–10 coils. M. honghuensis Liu et al. (2012) isolated from the pharynx of C. auratus gibelio was sampled in Hubei area, and its mature spore was 15.1–19.5 × 9.0–11.3 μm in size, polar capsule was 7.9–8.1 × 3.0–4.5 μm in size, and polar filament had 7–8 coils.

Proliferation and resistance difference of a liver-parasitized myxosporean in two different gynogenetic clones of gibel carp

“…To date, about 20 myxosporeans have been isolated from different tissues of gibel carp or crucian carp (Liu et al 2010;Ye et al 2012;Zhang et al 2010a, b;Zhao et al 2013). In this study, we have confirmed a significant difference of diseasing occurrence between two clones, a clone D that has been cultured for nearly 40 years and a novel clone A + that has been applied to aquaculture industry for only 5 years (Gui and Zhou 2010;Wang et al 2011).…”

Morphological and molecular characterisation of Myxobolus pronini n. sp. (Myxozoa: Myxobolidae) from the abdominal cavity and visceral serous membranes of the gibel carp Carassius auratus gibelio (Bloch) in Russia and China

“…Simple and variable morphological features of myxospores were acknowledged to be the main factors responsible for the difficulty of myxosporean taxonomy and species identification [6, 33, 34]. As such, the two geographical isolates of M. pronini n. sp.…”

Thelohanellus wangi n. sp. (Myxozoa, Myxosporea), a new gill parasite of allogynogenetic gibel carp (Carassius auratus gibelio Bloch) in China, causing severe gill myxosporidiosis

“…Reducing the severe negative effects of the myxosporidiosis on this commercially important species has been considered a priority in China. Until now, more than 40 myxosporean species belonging to Myxobolus, Thelohanellus, Hennegua, Sphaerospora, Myxidium, Myxobilatus, Hoferellus, Chloromyxum, Zschokkella and Unicauda genera have been found in allogynogenetic gibel carp, with high diversity of infection habitats (Xiao 1988;Chen and Ma 1998;Zhang et al 2006;Zhao et al 2008;Zhang et al 2010a, b;Liu et al 2012;Zhao et al 2013;Liu et al 2014a, b;Ye et al 2014). These myxosporean parasites can infect almost all stages of a whole culture cycle of this fish.…”