Two new species of Myxobolus (Cnidaria: Myxosporea) infecting freshwater fishes of Ranjit Sagar Wetland, Punjab, India

An update of the species of Myxosporea (Cnidaria, Myxozoa) described from Indian fish

A synopsis of Myxosporea (Cnidaria, Myxozoa) species described in about the last 14 years in Indian fish is provided. The synopsis include a total of 97 new species, and 18 species redescribed including significant new data, namely molecular characterization, distributed by 19 genera. For each species are indicated, in tabulated format, the morphological characteristics and the Gen Bank Accession Number whenever possible. Data about the type host and type locality are included also, and a complete list of references is provided. The information presented, combined with former synopsis, allow an update general view about these parasites infecting Indian fish hosts.

Phylogenetic analysis and characterization of a new parasitic cnidarian (Myxosporea: Myxobolidae) parasitizing skin of the giant mottled eel from the Solomon Islands

Myxosporeans are microscopic cnidarians associated with severe diseases in aquaculture and wild fish populations. This group of parasitic cnidarians thus warrants close attention concerning its potential impact on susceptible fish stocks. At present, little is known about this group of parasites infecting anguillid eels. From myxospore specimens collected from a freshwater eel (Anguilla marmorata) in the Solomon Islands, we describe a new species belonging to the genus Myxobolus based on an integrative taxonomic analysis of morphological, biological traits and molecular data. Furthermore, we determined the phylogenetic position and relationships of this species among other platysporine myxosporeans. Molecular phylogenetic assessment of small subunit ribosomal DNA showed that the species clusters together with Myxobolus portucalensis and Echinactinomyxon type 5 Özer, Wootten and Shinn, 2002, in a well-supported subclade. This is the first report of a myxosporean parasite infecting fish from the Solomon Islands.

Synopsis of the species of Myxobolus (Cnidaria, Myxozoa, Myxosporea) described between 2014 and 2020

A synopsis of the species of Myxobolus Bütschli, 1882 (Cnidaria, Myxosporea, Myxobolidae) described from 2014 up till now is presented. It includes 122 nominal species described all over the world. For each of the species, the most relevant morphological and morphometric data, as well as data are provided related to the location in the host, type host and type locality. The GenBank accession numbers are provided whenever possible, and the spores were redrawn based on the original descriptions. The bibliography includes all the papers containing the species descriptions.

Morphostructural data and phylogenetic relationships of a new cnidarian myxosporean infecting spleen of an economic and ecological important bryconid fish from Brazil

A new cnidarian myxosporean infecting the spleen of an economic and ecological important bryconid fish (Salminus franciscanus) is described based on integrative taxonomic approach including morphological, ultrastructural, biological traits, geography, molecular data and phylogenetic analysis. In a total of thirty specimens examined, nineteen (63.3%) were infected by an undescribed parasite species belonging to the genus Myxobolus. Plasmodial development was asynchronous, with young development in the periphery and mature myxospores in the central area and without projections and microvilli in the plasmodial wall. Mature myxospores were ovoid in shape and measured 7.9 ± 0.2 μm (7.6-8.1 μm) in length and 5.4 ± 0.1 μm (5.0-5.6 μm) in width. The two polar capsules were equal in size, occupying a little more than half of the myxospore body, measuring 4.0 ± 0.2 μm (3.9-4.1 μm) in length and 1.7 ± 0.1 μm (1.5-1.8 μm) in width. The polar tubules coiled in six turns, perpendicular to the long axis of polar capsule. Phylogenetic analysis placed the new species within a clade containing nine myxobolid species from South American characiforms fish and appears as a close species of Myxobolus pantanalis. Nevertheless, the sequences of the new species and M. pantanalis have a large genetic divergence of 13.5% in their SSU rDNA. In light of the differences observed from the integrative taxonomy, we confidently considered that this isolate is a new species of cnidarian myxosporean, M. douradae n. sp., increasing the knowledge of diversity of this enigmatic group of cnidarians.