Mandira Saha

Studies on histopathological alteration of three major organs of the goldfish, Carassius auratus L., of India due to myxozoan infection with special reference to scanning electron microscopic observation

Severe infections by the protozoan parasite belonging to the genera Myxozoa are causing serious problems in ornamental fish reared in breeding farms. Histopathological study is being used for diagnosis of the severity of diseases. Myxozoan infections result in large scale histopathological damages in different fish tissues. No information is available regarding the histopathological changes of goldfish due to infection with myxozoans. The present study deals with the histopathological changes of the gill, fin, and skin of goldfish, infected with myxozoan parasites along with an ultrastructural study using scanning electron microscope. Several histological alterations have been observed in goldfish, like tissue damage, epithelial hyperplasia, necrosis, anoxia, localized lymphocytic infiltration, excess mucus, cellular necrosis, and epithelial proliferation. The present study revealed the invasion intensified by the occurrence of morphological lesions in the gill, skin, and fin exposed to Myxosporidia, which may lead to respiratory insufficiency in fish and even cause mass mortality.

Seasonal incidence of protozoan parasitic infestation in ornamental fishes of West Bengal, India

The communication, dealing with the prevalence of protozoan parasites of the ornamental fish of West Bengal. During the study more than five hundred fish have been examined from five districts namely, Nadia, Hooghly, Howrah, North 24-pargana and South 24-pargana of West Bengal during pre-monsoon, monsoon and post-monsoon season. The study reveals that the intensity of infection is more in case of ciliate parasites. The highest ectoparasitic infection has been recorded during post-monsoon season, i.e. from November to February, followed by the pre-monsoon period while the lowest infection was recorded during monsoon i.e. from July to October which may lead to the conclusion that environmental factors are responsible for spreading infection.

First report of some known Trichodinella epizootica Šramek-Hušek, 1953, and Tripartiella Lom, 1959 from the cultured Oranda Gold Fish ( Carassius auratus auratus ) in India

Trichodiniasis of fishes cause economic losses in the fish industry through mortality and decrease growth rate. Very few studies of these ectoparasites have been made in India. A comprehensive icthyoparasotological survey in some ornamental fish farms of different parts of India has been done since March 2014-May 2015. During the study these trichodinid parasites have been identified from the gills of Oranda Gold Fish (Carassius auratus auratus L.). They are Trichodinella epizootica, Tripartiella viz. Tripartiella bulbosa, Tripartiella copiosa and Tripartiella obtusa. All these parasites have been recorded for the first time from the gills of Oranda Gold Fish (Carassius auratus auratus L.) in India i.e. The paper deals with the diversity and description of ciliophorans parasites of ornamental fish.

Occurrence of two new species of the genus Dipartiella (Raabe, 1959) Stein 1961 (Ciliophora: Trichodinidae) isolated for the first time from ornamental fish

During the parasitological survey of ornamental fish in India the authors identified two trichodinid ciliophorans for the first time in India, during the year 2014–16 and also revealed that goldfish, Carassius auratus, was the most susceptible species for trichodinid infection. Two ciliophorans have been isolated and identified on the basis of wet silver nitrate impregnation technique followed by taxonomic description, morphometric variability and comparative data with its closely related species. Considering all the important features including diameter, structure of denticles, rays and ciliatures the authors are of the opinion that the identified species are new to science. Hence, the name Dipartiella indiana n. sp. and Dipartiella carassii n. sp. are being proposed here. Till date, only two species of the genus have been described from the edible fish, but no attention has been paid to ornamental fish. Moreover, The present study confirms the first report of this genus from ornamental fish species and added two more species under the genus Dipartiella (Raabe, 1959) Stein 1961 along with new host, locality and prevalence rates.

Morphological and ssrDNA sequence based molecular characterization of a novel Thelohanellus species (Myxosporea: Myxobolidae) infecting the fins of Goldfish, Carassius auratus L. with special reference to its histopathological alteration

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.

Three New Species of Trichodina (Protozoa: Ciliophora) Isolated from Ornamental Fish, Carassius auratus from India

Surveys on the protozoan parasites of different ornamental fishes occurring in the farms of West Bengal, India during the year 2014–16 revealed that goldfish, Carassius auratus, was the most sensitive species for trichodinid infection. Three new species, namely, Trichodina indiana n. sp., Trichodina manjuae n. sp. and Trichodina vinodi n. sp. have been isolated and identified on the basis of dry silver nitrate impregnation technique followed by taxonomic description, morphometric variability and comparative data with its closely related species. T. indiana n. sp. has been uniquely characterized by their prominent denticular ring contains less angular acute denticle along with the large number of globular granules at the center of adhesive disc. Another two species T. manjuae n. sp. and T. vinodi n. sp. also described as new species, on the basis of their broad blade with extended well developed rays and sickle shaped, sharp denticle along with less prominent short rays respectively. The present study confirms the first report of this genus from Carassius auratus in India and added three more species under the genus along with new host, locality records and prevalence rates.

Identification of a new myxosporean parasite Thelohanellus indiana n. sp. (Myxosporea: Myxobolidae) isolated from three major organs of goldfish, Carassius auratus L. highlighted with its morphological and SSU rDNA sequence based molecular description

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.

Taxonomic Description of Two New Parasitic Species of the Genus Trichodinella (Raabe, 1950) Šramek-Hušek, 1953 (Ciliophora: Trichodinidae) isolated from Ornamental Goldfish, Carassius auratus L. with re-evaluation of their Host Specificity

Trichodiniasis of fishes cause harm and economic losses in the fish industry. There are many records of trichodinids ectoparasites infesting fish throughout the World, but no such attempt has been made to study the parasitic group infesting goldfish, Carassius auratus in India. During survey, an attempt have been made to survey trichodinid ciliophorans of some ornamental fish occurring in different parts of West Bengal, India and revealed the occurrence of two new species belonging to the genus Trichodinella on the basis of silver nitrate impregnation technique followed by taxonomic description, morphometric variability and comparative data in respect to closely related species. Trichodinella rectangulata n. sp., Trichodinella bengalensis n. sp. The species has been uniquely characterized by the acute, straight rectangular blade and elongated ray structure respectively. The present study confirms the first report of this genus from C. auratus and added two more species to the genus along with new host, locality records and prevalence rates.

Green Biosynthesis of Silver Nanoparticle Using Garlic, Allium sativum with Reference to Its Antimicrobial Activity Against the Pathogenic Strain of Bacillus sp. and Pseudomonas sp. Infecting Goldfish, Carassius auratus

Bacterial disease is a growing threat to aquaculture. The use of commercial antibiotics in aquaculture increases antibiotic resistance among pathogenic bacteria in exposed ecosystem and also creating environmental and public health hazards. As a consequence nowadays scientists are in search of alternate antibiotics. The use of Alliums by humans has a long history that can be traced back to the ancient Indians. Therefore, garlic-mediated synthesis of nanoparticles has garnered wide interest owing to its inherent features such as rapidity, simplicity, eco-friendliness and cheaper costs. This study deals with an environmentally friendly and biosynthesis process of antibacterial silver nanoparticles using an aqueous extract of Allium sativum. The formation and characterization of AgNPs was confirmed by scanning electron microscope and X-ray diffraction profile. Furthermore, the synthesized nanoparticles were examined against the pathogenic bacteria such as Pseudomonas aeruginosa PB112 (JN996498) and Bacillus licheniformis PKBMS16 (KX235179) infecting goldfish, Carassius auratus. From the experiment, it was found that the biologically synthesized nanoparticles by using A. sativum have a significant antibacterial activity and provide a scope for possible development of the formulations antimicrobial drug.Graphical Abstract