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Photograph showing the histological section of gill lamellae of host fish Labeo rohita (HEstained); a) Gill lamella of healthy Labeo rohita; b) histological sections cysts of Myxobolus sp.n PKB2014 attached to the gill lamellae. Gill lamella of healthy Labeo rohita, photograph showing the deformed gill lamellae of host fish (Labeo rohita) by attachment of the parasite; c) Round-shaped plasmodia attached to gill intra-lamellar sections of the host; d) scanning electron microscopic photomicrographs of plasmodia attached to the gill lamellar of the host fish; e. Ultra-structural study of Myxobolus sp.n PKB2014 spore.
Source publication
In India, more than 104 species of Myxobolus have so far been reported infecting freshwater as well as marine fishes. The study focuses on the description of a new myxosporean species, Myxobolus sp.n PKB 2014 from the gill lamellae of an Indian major carp Labeo rohita. The species have been described on the basis of morphological characterization o...
Citations
... Chakravarty and Basu (1948) similarity based on 18 S rDNA suggesting sister species, however, the morphological comparisons have also been proved by this molecular evidence. The study of evolutionary history enables us to understand the evolution of modern species and supports some uncertain topologies which are being presented regarding the morphometric analysis [43]. After T. habibpuri and T. caudatus the morphological comparison of the novel species have been supported by the T. nikolskii, T. bifurcata, T. calae, T. seni [35][36][37]39] regarding morphometric data which have also confirmed by the molecular data, i.e. these species were placed as a subbranch in phylogenetic tree from which the new Thelohanellus parasite has been placed and both the branches are originating from monophyletic clade that are supported by medium bootstrap values. ...
Fish mortality and poor growth in surviving fish contribute substantial losses to the ornamental fish farms of India and revealed an infection of a new myxosporidian parasite Thelohanellus indiana n. sp. which has become one of the most important limiting factors for successful aquaculture management. The parasite infects Carassius auratus, an Indian goldfish, described on the basis of myxospores morphology and amplification of a part of 18 S rDNA gene. Three major attaching site of fish body have been explored for showing the location of attachment for the parasites. The whitish cysts of the parasites are about 2.5-3.5 mm contains large amount of lemon shaped mature myxospores measuring 12.1-15.2 (13.8) × 7.5-8.8 (8) μm. A single round or elliptical polar capsule located only at the anterior pole of the spore having 6.2-7.2 (6.8) × 3.3-4.7 (4.0) μm in diameter. The morphological characters have been assessed by both the light and scanning electron microscope. The most differentiating feature from closely related species was carried out by morpho-taxonomic affinities with previously described species which are tremendously supported by molecular taxonomy by partial sequencing of the 18 S rDNA gene resulted in a total of 2101 bp fragment of newly obtained SSU rRNA gene sequence of the new species which exhibit 79-91% homogeneity with other closely related species available in GenBank. The BLAST search of Thelohanellus sp. did not matches with any available sequences in GenBank and the phylogenetic analysis revealed that the novel species were sister to T. habibpuri and T. caudatus, in the Thelohanellus clade and form a closest neighboring branch as a subclade in phylogenetic tree from which the new Thelohanellus parasite is being placed. Both the branches are originating from monophyletic clade that are strongly supported by bootstrap values which indicate clearly about independent position of T. indiana n. sp.
... The present study indicates close similarity based on 18S rDNA suggesting sister species, however, the morphological comparisons have also been proved by this molecular evidence. The study of evolutionary history enables us to understand the evolution of modern species and supports some uncertain topologies which are being presented regarding the morphometric analysis (Panda et al., 2015). After Thelohanellus caudatus and Thelohanellus habibpuri the morphological comparison of the novel species have been supported by the T. seni, T. catalae, T. bifurcata, T. batae, T. niloticus, T. rohitae (Chakravarty and Basu, 1948;Singh and Kaur, 2012;Chakravarty, 1943;Basu and Haldar, 1999;Kundu and Haldar, 1981;Abdel-Ghaffar et al., 2013) regarding morphometric data which have also confirmed by the molecular data, i.e. these species was placed as a sub-branch in phylogenetic tree from which the new Thelohanellus parasite have been placed and both the branches are originating from monophyletic clade that are supported by medium bootstrap values. ...
A new species of myxozoan, Thelohanellus goldi n. sp. is described using morphological and molecular data, parasitizing the fin filaments from 18 of 25 host specimens (72.5%) of Carassius auratus collected from different ornamental fish farms of India. Mature spore of the new species were oval to spherical in frontal view having rounded posterior ends and tapering anterior end measures 8.7-10.26 (9.50) × 4.10-7.89 (5.84) μm. The single large polar capsule, round to oval in shape but slightly pointed at the anterior end measuring 4.91-7.63 (5.60) × 2.3-3.1 (2.96) μm and located just below the anterior end of the spore. Polar filament only at distal end with 5-6 loose coils. The most differentiating feature from closely related species was carried out by morpho-taxonomic affinities with previously described species which are tremendously supported by molecular taxonomy by partial sequencing of the 18S rDNA gene resulted in a total of 2124 bp fragment of newly obtained small subunit ribosomal RNA gene sequence of the new species which Exhibit 93-95% homogeneity with other closely related species available in GenBank. The BLAST search and high genetic diversity of distance matrix of Myxobolus sp. did not properly match with any available sequences in GenBank and make sister clade with Thelohanellus caudatus and Thelohanellus habibpuri in the Thelohanellus clade including most of Thelohanellus spp. The study of evolutionary history enables us to understand the evolution of modern species and supports some uncertain topologies which are being presented regarding the morphometric analysis. The severity of myxozoan infection has been assessed in this article by observing the histopathological changes of fins of the C. auratus along with the diversity, distribution and taxonomic description of the new Thelohanellus species with their new host and locality records.
Growing emphasis on increasing aquaculture production involving
heavy stocking densities, use of growth promoters and import of seed
and fish from across the borders with no background of pathogenicity
are likely to inflict heavy mortalities coupled with severe economic
losses in the near future. It threatens to be seriously impacting the
aquaculture sector in India. A review of the known infectious diseases
belonging to the three categories, viz., bacterial, viral and parasitic, is
presented here. Bacterial diseases are widely prevalent, Aeromonas,
Pseudomonas, Streptococcus, Lactococcus and Vibrio being the most
common of the 92 known genera, infecting carps, catfishes, largemouth
bass, tilapia, rainbow and brook trout, mullets, eels, salmonids,
yellowtail are some of the group of fishes that suffer from bacterial
infections. Fish mortalities due to Streptococcus sp. and Lactococcus
sp. coupled with heavy economic losses are reported from various
parts of the world. Viral diseases are confined to a limited area and
inflict heavy mortality in young fish, the adults acting as carriers. Of
the known viral diseases, Koi Herpes Virus (KHV) stands out and
known for causing heavy mortality and monetary loss. However,
parasitic diseases despite being quite common are not known for
causing large-scale mortality but ichthyophthiriasis in carp nurseries
sometimes wipes out the entire stock while argulosis affects the
broodstock. Fish infected by Argulus fetches a low value in the market.
Clinical signs of infection and sites of infection along with photographs
are provided in each case along with the known treatment methods to
control the disease.
