Indian Freshwater Fish Research Articles

A comprehensive DNA barcoding of Indian freshwater fishes of the Indus River system, Beas

The Beas River is one of the important rivers of the Indus River system located in Himachal Pradesh, India, that harbors a diverse range of freshwater fish species. The present study employed COI gene to investigate the ichthyofaunal diversity of river Beas. Through the sequencing of 203 specimens from Beas River, we identified 43 species, belonging to 31 genera, 16 families, and 10 orders. To analyze the genetic divergence and phylogeny of identified species, 485 sequences of Indian origin were retrieved from BOLD, resulting in a dataset of 688 sequences. Our findings consistently revealed a hierarchical increase in the mean K2P genetic divergence within species (0.80%), genus (9.06%), and families (15.35%). Automated Barcode Gap discovery, Neighbour Joining, and Bayesian inference consensus tree methodologies were employed to determine the putative species and their phylogeny, successfully delimiting most of the species with only a few exceptions. The results unveiled six species exhibiting high intra-species divergence (> 2%), suggesting the presence of sibling species and falsely identified sequences on online databases. The present study established the first DNA barcoding-based inventory of freshwater fish species in the Beas River providing comprehensive insights into economically exploited endangered and vulnerable species. In order to ensure the sustainable use of aquatic resources in the Beas River, we recommend the implementation of species measures to protect biodiversity and genetic resources.

Diseases of freshwater fishes in India and its treatment: A review

Diseases of freshwater fishes in India and its treatment: A review

Abundance, characteristics, and risk assessment of microplastics in indigenous freshwater fishes of India

Microplastic (MP) pollution has pressing concerns regarding environmental health and the availability of safe food for humans. Information on the occurrence of MP in freshwater biota in the Indian scenario is currently lacking. The present study examined MP contamination in edible and non-edible tissues of widely consumed freshwater fishes. All the fish species (n = 35/species) analyzed had microplastic contamination with the highest MP abundance of 7.86 ± 2.0 items/individual in Channa punctatus followed by Labeo rohita (4.17 ± 0.6 items/individual) and Labeo bata (3.03 ± 0.4 items/individual); whereas MP abundance in small indigenous fishes (SIF) such as Salmostoma bacaila and Puntius amphibius accounts for 0.83 ± 0.13 and 0.77 ± 0.2 items/individual respectively. The principal component analysis results showed a 77.434% variance from two components identified for MP distribution. Fibre type MP was the most dominant type besides fragments and pellets that opined the type of MP required for ecotoxicity assessment, the need of the hour. Raman spectroscopy analysis confirms high-density and low-density polyethylene-type polymers. Evidence of MP in edible tissue indicates the translocation phenomenon resulting in human exposure through the consumption of biota contaminated with MP. Risk assessment revealed a low risk of MP based on its abundance while polymer type indicates a high risk for the fish species investigated. A thorough investigation of the level of adsorbed organic contaminants in the MP is warranted to address the interactive effects on biota. To the best of our knowledge, this is the first detailed report on MP contamination and its risk assessment in Indian freshwater fishes.

Synopsis of tailed Myxobolidae (Cnidaria, Myxozoa, Myxosporea) infecting Indian fishes.

A synopsis of 43 nominal species from five genera of tailed Myxobolidae infecting Indian freshwater and marine fishes is presented. The main characteristic of this group is the presence of at least one tail-like caudal process. For each species, relevant morphological and morphometric data are provided, such as the host(s), site(s) of infection within the host and sampling state. A key for the identification of 13 genera of tailed Myxobolidae is also included.

Toxicological effects of the textile industrial effluent to an Indian freshwater fish, Clarias batrachus

In this study, the histological effects of textile industrial effluent in the freshwater fish, Clarias batrachus was studied after 10, 20, and 30 days period of exposure. The 24, 48, 72, and 96 hours LC50 values were found to be 58.476, 53.231, 47.253, and 37.429% respectively. During the experiment, the treated fishes showed abnormal behaviors like erratic swimming, hyper-excitation, rapid opercular movement, and thick mucus covering which indicated the toxicity of the effluent. The observed changes in the gills were epithelial hyperplasia with lamellar fusion, necrosis, vacuolar degeneration, and atrophy of primary and secondary gill lamellae. On the other hand, the liver showed the formation of the number of vacuoles, enlargement of nuclei of some cells, degeneration of cytoplasm in hepatocytes, atrophy, a rupture in blood vessels, and disposition of hepatic cords. The kidney also showed abnormalities like degeneration of proximal and distal convoluted tubule, vacuolation of renal interstitial tissue, necrosis, cellular hypertrophy, and granular cytoplasm.

Molecular identification, whole-cell protein profiling, antibiotics sensitivity and pathogenicity of Chryseobacterium gleum recovered from diseased fishes of freshwater wetlands in India

Globally, bacterial gill disease is one of the most prominent bacterial diseases affecting both marine and freshwater fishes. This study aimed to investigate diseased Labeo rohita, Labeo catla and Oreochromis niloticus with gill discoloration, tail rot and skin ulcer that resembles the typical sign of bacterial gill disease from East Kolkata Wetlands, India. The results revealed that four isolates of Chryseobacterium gleum were the responsible pathogens. The isolates CIFRI-RRM3, CIFRI-BFG2, CIFRI-SRM4 and CIFRI-TRM5 were identified using bacterial colony morphology, biochemical test, whole-cell protein profiling, 16S rRNA gene amplification and nucleotide sequence analysis. The antibiotic susceptibility assay showed that all the isolates were completely resistant to ampicillin, amoxyclav, cefalexin, cephalothin, ceftriaxone, ceftazidime, cefotaxime, cefuroxime, cefadroxil, chloramphenicol, kanamycin, netilmicin, penicillin-G, ticarcillin, tobramycin, erythromycin and tetracycline. A challenge experiment was also conducted for four isolates with intraperitoneal injection at a dose of 2.5 × 1010 CFU mL−1 to 4.2 × 1010 CFU mL−1in respective fish hosts. Only three isolates (CIFRI-BFG2, CIFRI-RRM3 and CIFRI-TRM5) proved their virulence by producing diseases with mild symptoms of skin lesions, gill disease and cumulative mortality of 10–20%. To the best of our knowledge, this is the first description of the phenotypic, molecular and whole-cell protein profiling of C. gleum derived from freshwater fishes in India.

DNA barcoding and phylogenetic relationship of two fish species of genus Garra (Family: Cyprinidae) from Aravalli region of Southern Rajasthan based on mtDNA COI sequences

The genus Garra (stone sucker), Family Cyprinidae, consists of a group of species that are remarkably similar in morphology. These species are often difficult to distinguish based on external morphological approach. To resolve the existing uncertainty about the relationships and groups of these fishes, an attempt has been made to study the phylogenetic relationships of Garra gotyla and Garra mullya using mtDNA COI gene sequences from Aravalli region of Southern Rajasthan. The sequences were submitted to NCBI GenBank to establish and validate the taxonomical identification of the samples. A total of 5 COI sequences were generated. The overall GC content of Garra gotyla and Garra mullya were 44.13 and 43.00% respectively. The genetic distance within groups was 0.001 and 0.01 for G. gotyla and G. mullya respectively. The Neighbour-joining tree of two fish species using COI gene data revealed two distinct groups with 0.157 divergence. DNA barcode discriminated congeneric species without any confusion. The study strongly validated the efficiency of COI as an ideal marker for DNA barcoding of Indian freshwater fishes.

Molecular Characterization of Two Myxosporean Species, Henneguya namae Haldar et al. 1983 and Myxobolus sophorae Jayasri, 1982 (Myxosporea: Myxobolidae)

In Indian freshwater fish myxosporean infections are among the most cosmopolitan parasites, they are relatively well studied morphologically but their phylogenetic relationships were unclear and the genetic data is limited only to a few species. The study aims to present molecular data for two myxosporean species, Henneguya namae Haldar et al. 1983 and Myxobolus sophorae Jayasri, 1982 collected from Indian freshwater fish, the elongate glass-perchlet Chanda nama (=Ambassis nama) and pool barb Puntius sophore, respectively. In the present study molecular data are provided for H. namae and M. sophorae using nested PCR. The obtained partial 18S rDNA gene sequences were analyzed using maximum likelihood (ML) and Bayesian inference (BI) methods. The 18S rDNA gene sequences of H. namae showed similarity with the sequences of H. chaudhuryi, Henneguya sp. RA-2015, H. voronini and H. setiuensis about 72.1 to 78% and M. sophorae with Myxobolus ticto was about 90% respectively. The aim of this paper was to identify H. namae and M. sophorae morphologically and using molecular methods.

Molecular Genetic Studies on Myxobolus cylindricus and Henneguya mystasi (Myxosporea: Myxobolidae) Infecting Two Indian Fish Species, Channa gachua and Mystus vittatus, Respectively.

Myxozoan infections of Indian freshwater fishes are relatively well studied, but their validity is supported with molecular and phylogenetic data only for a few species. The primary objective was to present molecular data for two Myxozoan species, Myxobolus cylindricus and Henneguya gachua collected from Indian freshwater fishes, the dwarf snakehead Channa gachua and the striped dwarf catfish Mystus vittatus, respectively. Various organs of 56 C. gachua and 48 M. vittatus were dissected. Myxozoan plasmodia with mature spores were collected from the gills under a dissecting microscope. Spores obtained from plasmodia from infected hosts were fixed in 80% ethanol in vials and sent for further morphological and molecular examinations to Hungary. The 18S rDNA gene of Myxobolus and Henneguya spp. was amplified using nested polymerase chain reaction (PCR). Phylogenetic analysis was performed using maximum likelihood (ML) and Bayesian inference (BI) methods. Morphological characteristics of M. cylindricus and H. mystasi spores corresponded to the original descriptions made by Sarkar, Mazumdar and Pramanik, 1985 and Haldar, Samal, and Mukhopadhyay, 1997, respectively. Phylogenetic analysis of the 18S rDNA gene revealed that the sequences of M. cylindricus differed from those of most Indian Myxobolus sp., known mostly from cyprinid fishes and formed a subgroup with Myxobolus neurophilus, a parasite of a perciform host, and with Henneguya chaudhuryi, a species belonging to a different genus but described from a closely related channid host. It was also closely related to another Henneguya species, H. lesteri, described from Sillago analis, a coastal fish. Henneguya mystasi had the closest similarity to Henneguya bicaudi, a species described from an Indian cyprinid fish and to Henneguya pellucida reported from a characid fish known from South America. Molecular data received by us gives a solid basis for further identification of these myxozoans, the pathogenicity of which probably plays an economic role at culturing the hosts.

Seasonal Variations in Proximate Composition of Nine Freshwater Fish

The variation in proximate composition was determined in relation to season and body weight of nine freshwater fish i.e. Mystus vittatus, Ompok bimaculatus, Channa striata, Wallago attu, Pangasianodon hypophthalmus, Labeo bata, Labeo calbasu, Cirrhinus reba and Puntius javanicus. The samples were collected in different seasons from different places and divided into small and big body weight groups. Nutritional composition of fish species was determined during the three seasons i.e. S1 (January-April), S2 (May-August) and S3 (September-December) of the year. Protein content ranged from 12.52–19.19% among the species on wet weight basis. Protein content was higher (P 100 g) during January-April. Protein, fat and ash content of P. javanicus was higher (P 100 g) during S3 (September-December). Protein content was higher (P 500 g) size group. Fat content of the L. bata was higher (P 100g size group during S1 (January-April). Protein content was higher in W. attu of >1000 g size group during S2 (May-August). P. hypopthalamus of (>1000 g) size group revealed that fat content was higher (P<0.01) during S3 (September-December). Thus, Indian freshwater fish are rich in protein, fat and ash contents and qualify as health food though there were some seasonal variations in proximate composition within the fish species.

Molecular identification of two cestodes species parasitizing freshwater fishes in India.

In the present study, molecular identification of two species of cestodes, Lytocestus indicus and Senga lucknowensis infecting freshwater fishes Clarias magur and Channa punctata, respectively in Manipur is carried out. To ascertain the taxonomic status of these helminth parasites, 18S gene marker was used. Phylogenetic analysis of 18S of Lytocestus sp. showed that it claded with L. indicus from Indian Isolate with a sequence similarity index of 99%. In case of Senga sp., the phylogenetic analysis revealed that it formed a separate clade with S. lucknowensis and Senga vishakapatnamensis, and the sequence similarity index showed maximum homogeneity with S. lucknowensis i.e., 99.8%. Thus, molecular characterization revealed that the two species of cestodes belong to L. indicus and S. lucknowensis.

Comparative Assessment of Nutritional Composition in Raw and Cooked Indian Freshwater Fish Lepidocephalus thermalis (V.)

Lepidocephalus thermalis, the Indian Spiny Loach is an IUCN least concern status edible freshwater fish with indigenous flavor and taste found endemic in Tamil Nadu. In this study, the proximate nutritional composition, amino acid, vitamin, fatty acid, micro and macro mineral analyses for raw and boiled fish samples were estimated instantaneously as cooking could lead to changes in the level of certain nutrients. This fish is with 33.09% saturated, 32.86% mono unsaturated and 30.49% polyunsaturated fatty acids. The predominant amino acids were glycine (715 mg/100 g), histidine (375 mg/100 g), alanine (237 mg/100 g) and arginine (130 mg/100 g). The fish comprised a good level of calcium (924 mg/100 g), zinc (0.14 mg/100 g) and iron (1.86 mg/100 g). Boiled fish had reduced level of certain amino acids like glycine (410 mg/100 g) and alanine (124 mg/100 g). There was no significant difference in the fatty acid composition in the boiled fish.

DNA Barcoding and Phylogenetic Relationships of Selected South Indian Freshwater Fishes Based on mtDNA COI Sequences

DNA barcoding is an effective tool for the identification of species representing diverse taxa especially through the sequence analysis of mitochondrial cytochrome c oxidase subunit I (COI) gene. In the present study, DNA barcodes were generated from 46 species of freshwater fishes covering the Orders Cypriniformes, Siluriformes, Synbranchiformes and Perciformes representing 30 genera under 9 families. All the samples were collected from diverse sites which also includes some endemic species. A total of 47 COI sequences were generated. After amplification and sequencing of 678 base pair fragment of COI, primers were trimmed which invariably generated a 635 base pair barcode sequence. The average Kimura two-parameter (K2P) distances within-species, genera, families, and orders were 0.32%, 8.40%, 14.50%, and 18.65%, respectively. DNA barcode discriminated congeneric species without any confusion. The present study strongly supports the efficiency of COI as an ideal marker for DNA barcoding of selected freshwater fishes.

Molecular characterization of three species belongs to the Allocreadioidea, Hemiuroidea and Plagiorchioidea (Platyhelminthes: Trematoda) infecting freshwater fishes in India

Summary Three species of digenetic trematodes are redescribed based on specimens collected from the intestine of freshwater fishes of Hastinapur and Meerut (U.P.), India: Allocreadium handiai (Pande, 1937) Madhavi, 1980 (Allocreadioidea: Allocreadiidae) from Mystus tengara (Hamilton, 1822) (Siluri-formes: Bagridae), Genarchopsis goppoOzaki, 1925 (Hemiuroidea: Derogenidae) and Phyllodistomum chauhaniMotwani &amp; Srivastava, 1961 (Plagiorchioidea: Gorgoderidae) from Channa punctata (Bloch, 1793) (Perciformes: Channidae). The three species were subjected to morphological, morphometric and molecular analyses. The morphological study revealed that A. handiai, G. goppo and P. chauhani can be distinguished by their congeners on the basis of their morphology. Partial nucleotide sequences of the 28S ribosomal RNA gene were obtained from the three trematode species and deposited in the GenBank. A phylogenetic reconstruction based on the 28S rRNA gene placed the three studied species within their respective families and their validity is discussed. For the first time molecular data of newly collected material of these species from India were used for confirmation of their validity and to assess their phylogenetic relationships.

Characterization, virulence and pathology of Flavobacterium sp. KG3 associated with gill rot in carp, Catla catla (Ham.)

“Gill rot” caused by the Gram negative, long, rod shaped bacterium Flavobacterium sp. in a sewage fed farm growing Indian major carps in West Bengal, India, is described. The phenotypic and molecular characteristics, virulence and pathology of Flavobacterium sp. strain KG3 are also documented. The infected catla Catla catla had cutaneous haemorrhages, white patches on body and gill, gill rot and excess mucus secretion. On selective cytophaga agar, the isolate produced non-rhizoid yellow pigmented colonies. Phylogenetically, the strain KG3 was distinctly different from the closely related type strains of Flavobacterium species, though it branched with type strain F. hydatis DSM 2063 (NCBI accession number AM230487) with low node value. Histologically, the naturally infected catla gills showed cartilaginous tissue inflammation, mucus secretion, necrosis of gill filament with associated reduction in the number of lamellae per filament, obliteration of interlamellar water channels, and fusion of lamellae. Catla catla fingerlings experienced about 57% moralities within 5days of abrasion and immersion in a bath containing 4.7×106Flavobacterium sp. cells/mL. The abraded and unchallenged fingerlings recorded 20% mortality in 3days. These results demonstrated the virulence of Flavobacterium sp. in catla especially during the winter season, which warrants its management measures. Statement of relevanceFlavobacterium spp. are emerging as major pathogens of Indian freshwater fish. They can cause chronic mortalities in fish at low water temperature. Correct diagnosis and understanding the pathology would help manage flavobacterial infection in fish.

Species diversity of the genus Thelohanellus Kudo, 1933 (Myxozoa: Bivalvulida) parasitizing fishes in Indian subcontinent.

A synopsis of 52 nominal species of the genus Thelohanellus Kudo, 1933 reported to infect freshwater fishes in India is presented. These species infect various organs such as gills, fins, scales, skin, muscles, gall bladder, kidney etc. The diagnostic features of the genus include tear-shaped myxospores with smooth shell valves and single polar capsule. The members are histozoic in their nature of parasitism infecting fresh water fishes. The present manuscript is aimed to compile the list of reported species in India along with essential information on morphometrics of vegetative stage, host, organ preference and pathogenic effects if any. Maximum number of species are recorded from state of West Bengal (25) followed by 23 in Punjab (out of which 8 were already reported from other states of India), Andhra Pradesh (7), Orissa (3), Manipur (1) and Haryana (1). Majority of the species have been recorded to infect major and minor carps (43 species) and 9 species in cat fishes. Out of 43 species infecting Indian major carps, T. batae infected the epithelial lining of gill filament of Labeo bata and also the wall of the duodenum and pectoral fin of Wallago attu in Harike Wetland (Punjab). Organ distribution of the species belonging to the genus Thelohanellus indicated that the plasmodia of 27 species were located in the gills, 14 species in the fins, 7 species in the gall bladder, 4 species in muscles and 3 species in kidney, 2 each in scale and skin on the head region and 1 species each in brain, eye, spleen, liver and wall of the duodenum. Recent studies conducted by the authors and also by few earlier studies in West Bengal have documented many species of Thelohanellus to cause serious gill haemorrhagic disease and dermal lesions. Histological studies on the gills of cultured carps in Punjab infected with members of Thelohanellus have indicated that these parasites cause 15-20% damage to respiratory surface leading to localized loss of function.

Applications in environmental risk assessment of biochemical analysis on the Indian fresh water fish, Labeo rohita exposed to monocrotophos pesticide.

Pesticides are widely used in modern agriculture to aid in the production of high quality food. However, some pesticides have the potential to cause serious health and environmental damage. Repeated exposure to sub-lethal doses of pesticides can cause physiological and behavioral changes in fish that reduce populations such as abandonment of nests and broods, decreased immunity to disease and increased failure to avoid predators. Monocrotophos is one of the organophosphorus pesticide used in this study. The median lethal concentration (LC50) of Monocrotophos to fish L. rohita for 96h was found to be 45.1ppm. In sublethal concentration (1/10th of LC50 96h value, 4.51ppm) fishes were exposed for 24, 48, 72, 96h and 10, 20 and 30days. Organs of fishes were sacrificed and tested for biochemical analysis. A significant decrease in protein, carbohydrate and lipids were observed throughout the study period when compared to the control. It is essential for assessing the ecological risk of these pesticides.

Effect of Dietary Supplementation of Bacillus subtilis and Terribacillus saccharophillus on Innate Immune Responses of a Tropical Freshwater Fish, Labeo rohita

Objective: Indiscriminate use of antibiotics to control fish diseases has led to the development and propagation of antibiotic resistant bacteria in aquatic ecosystems. Amongst the various alternatives proposed, enhancing immunity in fish using probiotics is the most widely accepted approach. Several earlier studies indicated the possibility of more potent effects of bacteria on fish when administered in live condition than as inactivated cells. But very few studies have explored the effect of gut bacteria on innate immune responses of fishes. Hence an attempt is made to study immunostimulatory effects of dietary supplementation of Bacillus subtilis and Terribacillus saccharophillus isolated from the gut of an edible Indian freshwater fish, Labeo rohita, in the same species. Methods: Long term administration (for 30 and 60 days) of B. subtilis or T. saccharophillus isolated from the gut wall of L. rohita were tested in the same species for their ability to improve innate immunity through measurement of the phagocytic activity, respiratory burst, myeloperoxidase activity, serum IgM levels, serum lectins, haemagglutination and haemolytic activity. Results: Dietary administration of 107 cfu/g of B.subtilis/T. saccharophillus for 30 (B1) or 60 (B2) days resulted in a significant increase in immune and humoral responses of L. rohita. Serum phagocytic activity, respiratory burst activity, myeloperoxidase activity, serum lectins, haemagglutination and haemolytic activity increased upon administration of B.subtilis / T. saccharophillus, except serum IgM levels which increased only in B1. A positive correlation was observed between the duration of supplementation of diets and the responses in both the cases. Conclusion: The results suggest that T. saccharophillus can also be used as a potent probiont similar to B.subtilis and both will have significant applications in fish feed formulations and disease prevention.

DNA barcoding Indian freshwater fishes

DNA barcoding is a promising technique for species identification using a short mitochondrial DNA sequence of cytochrome c oxidase I (COI) gene. In the present study, DNA barcodes were generated from 72 species of freshwater fish covering the Orders Cypriniformes, Siluriformes, Perciformes, Synbranchiformes, and Osteoglossiformes representing 50 genera and 19 families. All the samples were collected from diverse sites except the species endemic to a particular location. Species were represented by multiple specimens in the great majority of the barcoded species. A total of 284 COI sequences were generated. After amplification and sequencing of 700 base pair fragment of COI, primers were trimmed which invariably generated a 655 base pair barcode sequence. The average Kimura two-parameter (K2P) distances within-species, genera, families, and orders were 0.40%, 9.60%, 13.10%, and 17.16%, respectively. DNA barcode discriminated congeneric species without any confusion. The study strongly validated the efficiency of COI as an ideal marker for DNA barcoding of Indian freshwater fishes.

God's fishes: religion, culture and freshwater fish conservation in India

AbstractIndigenous communities worldwide have long relied on their environment for survival. Religious and customary beliefs that foster community conservation have not only bound these communities to ecosystems but also assisted in the conservation of species. We provide an example of how religion fosters the conservation of freshwater fishes in India. Since ancient times rural communities in India have revered fish species as symbols of divine power, and offered them protection in pools associated with temples. Such voluntary, informal institutions and arrangements continue to help conserve several freshwater fish species that are otherwise subjected to anthropogenic pressure in open-access areas. However, religious beliefs in India are waning as a result of increased urbanization, modernization of societies and disintegration of rural communities, and the sustainability of existing temple and community fish sanctuaries is questionable. We discuss the role of temple sanctuaries as an informal conservation strategy for freshwater fishes, and discuss the knowledge and policy gaps that need to be addressed for ensuring their future.