Development of novel microsatellite markers for population differentiation and detection of natural selection in wild populations of butter catfish, Ompok bimaculatus (Bloch, 1794).

BACKGROUND: Butter catfish (Ompok bimaculatus) is a preferred species in South East Asia, with huge aquaculture potential. However, there is limited information about genetic stock composition due to insufficient markers. The goal of this study was to develop de novo microsatellite markers. METHODS AND RESULTS: For sequencing, genomic SMRT bell libraries (1.5 Kbp size) were prepared for O. bimaculatus. A total of 114 SSR containing sequences were used for primer designing. Polymorphic loci were validated by genotyping 83 individuals from four distant riverine populations, viz., Brahmaputra, Bichiya, Gomti and Kaveri. A total of 30 microsatellite loci were polymorphic, of which five were found to be associated with functional genes and eight (four positive and four negative) loci were found to be under selection pressure. A total of 115 alleles were detected in all loci and PIC ranged from 0.539 to 0.927 and pair-wise FST values from 0.1267 to 0.26002 (p < 0.001), with an overall FST value of 0.17047, indicating the presence of population sub-structure. Cross-species transferability of 29 loci (96.67%) was successful in congener species, Ompok pabda. CONCLUSION: The novel SSR markers developed in this study would facilitate stock characterization of natural populations, to be used in future selection breeding programs and planning conservation strategies in these species. Identified non-neutral markers will give insights into the effect of local adaptation on genetic differentiation in the natural population of this species.

Quantitative assessment of sediment delivery and retention in four watersheds in the Godavari River Basin, India, using InVEST model - an aquatic ecosystem services perspective.

Sediment export and retention are important ecosystem processes in any landscape causing soil erosion and sediment loading in waterways consequently affecting the health of aquatic habitats downstream. The present study quantifies sediment export and retention in four watersheds, viz., Hivra, Satrapur, Konta, and Jagdalpur in the Godavari River Basin, India, using Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) ecosystem service modelling tool. The  results revealed that the sediment export yields ranged from 0.75 (Hivra) to 2.77 t/ha/year (Jagdalpur). The mean deviation between modelled values and observed sediment export yield was - 11.11%, which indicated good prediction by the model. The sediment retention ranged from 16.04 (Hivra) to 101.52 t/ha/year (Konta). Most sediment export and retention occurred on cropland or shrubland land use land cover types in all four watersheds. For decision making on soil conservation, soil loss tolerance limits have been established for these watersheds. For aquatic habitats, sediment concentration is considered more important than the total annual sediment export, since water turbidity is an important determinant of water quality, and the aquatic lives therein. Therefore, the temporal distribution of rainfall and corresponding sediment export becomes important, since these two factors determine the sediment concentration as well as turbidity in the waterbody. In current study, "Precipitation Concentration Index adjusted Sediment Export Yield Index" was developed to account for the effects of the temporal rainfall distribution and its impact on sediment export. The index for four watersheds was quantified (Hivra > Satrapur > Konta > Jagdalpur), which is concordant to the turbidity values reported by respective gauge stations. Thus, the proposed index can efficiently capture the impact of temporal rainfall distribution on sediment export, and consequently its effect on water turbidity. The study revealed the potential of InVEST model to quantify the sediment export and retention in the watersheds studied. Together with the proposed index, it would help the policy makers in making informed decisions for planning conservation strategies for aquatic biodiversity.

Description of a new Pangasius (Valenciennes, 1840) species, from the Cauvery River extends distribution range of the genus up to South Western Ghats in peninsular India.

A new species of the genus Pangasius, is described based on 17 specimens collected from the Cauvery River, India. It can be distinguished from its sister species from South and Southeast Asia, by its widely placed, small and rounded vomerine and palatine tooth plates, longer maxillary and mandibular barbels, greater vertebrae count 50 (vs. 44-48), and smaller caudal peduncle depth (6.5-8.2% SL vs. 9.89-13.09% SL). The tooth plates of the new species closely resembles that of Pangasius macronema but can be clearly distinguished from the latter by having lesser gill rakers (16-19 vs. 36-45); a smaller eye (2.4-4.4% SL vs. 5.2-9.6% SL); and larger adipose-fin base (1.5-2.9% SL vs. 0.1-1.2% SL). The mitochondrial cytochrome c oxidase (COI) gene sequence of the new species shows the genetic divergence of 3.5% and 5.1% from P. pangasius and P. silasi respectively, the two sister species found in South Asia and India. The species delimitation approaches, Poisson Tree Processes (PTP) and assemble species by automatic partitioning (ASAP) clearly resolved that the P. icaria is distinct from its sister species. Phylogenetic position of the species with its sister species was evaluated using maximum likelihood and Bayesian analysis. The discovery of this previously unknown species of genus Pangasius from the Cauvery River of peninsular India indicates important biogeographical insight that this genus migrated till the southern division of Western Ghats.

Applications of Sentinel-2 satellite data for spatio-temporal mapping of deep pools for monitoring the riverine connectivity and assessment of ecological dynamics: a case from Godavari, a tropical river in India (2016-2021).

Rivers are dynamic ecosystems with diverse habitats that require ample connectivity to ensure the flow of ecosystem services, thus empowering the sustainable development of an entire basin. Geo-spatial tools offer powerful prospects for monitoring of aquatic ecosystems. The usefulness of Sentinel-2 datasets to assess river connectivity has been explored for an un-gauged seasonal river system. The present study was undertaken in five ecologically unique river reaches viz. Wainganga, Wardha, Pranhita, Godavari-mid and Manair in Godavari Basin in the Indian Deccan Plateau to map water spread dynamics at various time scales, i.e., fortnightly, monthly, seasonal, annual and demi-decadal during 2016-2021. The maximum value of perennial water spread per square kilometre of total floodplain area (2016-2021), determined using Sentinel-2 imageries, was observed in river Wardha (0.18) followed by Pranhita (0.12) and Wainganga (0.11). The water spread showed a decreasing trend, while the number of patches in the river corridor increased over time from post-monsoon to pre-monsoon season. The copious perennial habitat with relatively larger patches, incessant flow in river Pranhita and obstructed flow, large-sized patches reported in river Wardha during summer months, hold importance in terms of providing refuge to aquatic biota. This study provides evidence for the impact of water projects on spatio-temporal water spread dynamics in Godavari Basin. The demonstrated utility of Sentinel-2 imagery coupled with gauge station measurements for river continuity assessment and deep pool mapping would aid in enhancing our understanding on environmental flow at a spatial scale, which in turn would aid in effective river management to achieve the Sustainable Development Goals. The implications of this study for sustainable environmental management and limitations are also discussed.

Clinical Radiographic Evaluation of 3Mixtatin and MTA in Primary Teeth Pulpotomies: A Randomized Controlled.

Introduction: The present study evaluates the efficiency of 3Mixtatin (a combination of Simvastatin and 3Mix antibiotics) in comparison with Mineral Trioxide Aggregate in primary molars pulpotomy. Materials and methods: A total of 64 deciduous molar teeth with caries requiring pulpotomy procedure were selected and randomly divided into two treatment groups, Group I- MTA (n = 32), Group II- 3Mixtatin (n = 32). Restoration with Glass Ionomer Cement followed by stainless steel crowns was done after pulpotomy procedure. The clinical and radiographical analysis was done in the subsequent follow-up periods of 3, 6, 9, and12 months simultaneously. Result: Both groups showed equal success rates, without any significant difference between the MTA and 3mixtatin groups clinically (success rate of 93.8%)and radiographically higher success rate was seen with 3Mixtatin (78% success rate). Conclusion: 3mixtatin showed similar clinical and better radiographical success rate to MTA. Therefore, 3mixtatin may be a potential alternate pulpotomy medicament in primary teeth. Key messages: In the present study based on the radiographic findings, 78% success rate was seen in the teeth treated with 3Mixtatin, which was higher than the radiographic success rate of MTA (75%). Therefore, it is reasonable to assume the use of 3Mix with Simvastatin to treat pulpotomized primary molars by 3Mixtatin. How to cite this article: Chak RK, Singh RK, Mutyala J, et al. Clinical Radiographic Evaluation of 3Mixtatin and MTA in Primary Teeth Pulpotomies: A Randomized Controlled Trial. Int J Clin Pediatr Dent 2022;15(S-1):S80-S86.

Phenotypic variation of Chitala chitala (Hamilton, 1822) from Indian rivers using truss network and geometric morphometrics.

Chitala chitala (Hamilton, 1822) is an economically important food fish species occurring throughout Indian rivers, which also has ornamental value. This study focuses on morphological variations in C. chitala from seven river basins across India namely; Son, Tons, Ken, Brahmaputra, Ganga, Gomti and Gandak. A truss network was constructed by interconnecting nine landmarks to generate 36 morphometric variables extracted from digital images of specimens sampled from the study locations. Transformed truss measurements were subjected to principal component analysis (PCA), canonical discriminant function analysis (CDFA) and discriminant analyses of principal components (DAPC). DAPC function coefficients performed much better in capturing the variation pattern and discrimination between the rivers which was not achieved using CDFA. Eight truss variables were identified with significant and highest loading for truss variables on principal components and coefficients on discriminant function from DAPC contributing to maximum variation between the rivers. Performance graph and functional distribution of identified truss variables clearly indicated distinction between the rivers. Thin plate spline analysis and procrustes shape analysis further showed the variation in morphology between specimens across the rivers. The significant parameters differentiating specimens from different rivers were linked to dorsal fin origin, the base of the pectoral fin and the perpendicular point on the anal fin from the dorsal fin origin. Variation in the hydrodynamics of the rivers studied might be possibly affecting the fin kinematics and consequently leading to adaption seen as phenotypic variation in C. chitala. The results showcased in the present study shall help in better understanding of intra-specific diversity which is significant for management and conservation of a species.

Genetic and morphological assessment of a vulnerable large catfish, Silonia silondia (Hamilton, 1822), in natural populations from India.

Silonia silondia is a commercially important fish distributed in Asian countries, which is under threat due to overexploitation. This study focuses on the morphological analysis and genetic variation of S. silondia individuals, through truss network and sequencing of two mitochondrial regions, respectively, from six wild populations of the Ganga and Mahanadi river systems in India. A total of 38 haplotypes was observed by analysing combined mitochondrial genes (cytochrome b + ATPase 6/8) in 247 individuals of S. silondia collected from six populations. Average haplotype and nucleotide diversities were 0.8508 and 0.00231, respectively. Genetic structure analysis showed the predominant cause of genetic variation to be within populations. The two clades were observed among the haplotypes and time of divergence from their most probable ancestor was estimated to be around 0.3949 mya. Analysis of combined mitochondrial genes in six populations of S. silondia resulted into three management units or genetic stocks. The truss network analysis was carried out by interconnecting 12 landmarks from digital images of specimens to identify phenotypic stocks. Sixty-five truss morphometric variables were analysed for geometric shape variation which revealed morphological divergence in River Son specimens. The present study presents molecular markers and genetic diversity data which can be critical input for conservation and management of differentiated populations and future monitoring of the genetic bottleneck. The morphological shape analysis clearly shows that variation in the insertion of adipose fin is an important parameter influencing the morphological discrimination.

Draft genome assembly of Tenualosa ilisha, Hilsa shad, provides resource for osmoregulation studies.

This study provides the first high-quality draft genome assembly (762.5 Mb) of Tenualosa ilisha that is highly contiguous and nearly complete. We observed a total of 2,864 contigs, with 96.4% completeness with N50 of 2.65 Mbp and the largest contig length of 17.4 Mbp, along with a complete mitochondrial genome of 16,745 bases. A total number of 33,042 protein coding genes were predicted, among these, 512 genes were classified under 61 Gene Ontology (GO) terms, associated with various homeostasis processes. Highest number of genes belongs to cellular calcium ion homeostasis, followed by tissue homeostasis. A total of 97 genes were identified, with 16 GO terms related to water homeostasis. Claudins, Aquaporins, Connexins/Gap junctions, Adenylate cyclase, Solute carriers and Voltage gated potassium channel genes were observed to be higher in number in T. ilisha, as compared to that in other teleost species. Seven novel gene variants, in addition to claudin gene (CLDZ), were found in T. ilisha. The present study also identified two putative novel genes, NKAIN3 and L4AM1, for the first time in fish, for which further studies are required for pinpointing their functions in fish. In addition, 1.6 million simple sequence repeats were mined from draft genome assembly. The study provides a valuable genomic resource for the anadromous Hilsa. It will form a basis for future studies, pertaining to its adaptation mechanisms to different salinity levels during migration, which in turn would facilitate in its domestication.

Muscle transcriptome resource for growth, lipid metabolism and immune system in Hilsa shad, Tenualosa ilisha.

The information on the genes involved in muscle growth, lipid metabolism and immune systems would help to understand the mechanisms during the spawning migration in Hilsa shad, which in turn would be useful in its future domestication process. The primary objective of this study was to generate the transcriptome profile of its muscle through RNA seq. The total RNA was isolated and library was prepared from muscle tissue of Tenualosa ilisha, which was collected from Padma River at Farakka, India. The prepared library was then sequenced by Illumina HiSeq platform, HiSeq 2000, using paired-end strategy. A total of 8.68 GB of pair-end reads of muscle transcriptome was generated, and 43,384,267 pair-end reads were assembled into 3,04,233 contigs, of which 23.99% of assembled contigs has length ≥ 150 bp. The total GO terms were categorised into cellular component, molecular function and biological process through PANTHER database. Fifty-three genes related to muscle growth were identified and genes in different pathways were: 75 in PI3/AKT, 46 in mTOR, 76 in MAPK signalling, 24 in Janus kinase-signal transducer and activator of transcription, 45 in AMPK and 27 in cGMP pathways. This study also mined the genes involved in lipid metabolism, in which glycerophospholipid metabolism contained highest number of genes (32) and four were found to be involved in fatty acid biosynthesis. There were 58 immune related genes found, in which 31 were under innate and 27 under adaptive immunity. The present study included a large genomic resource of T. ilisha muscle generated through RNAseq, which revealed the essential dataset for our understanding of regulatory processes, specifically during the seasonal spawning migration. As Hilsa is a slow growing fish, the genes identified for muscle growth provided the basic information to study myogenesis. In addition, genes identified for lipid metabolism and immune system would provide resources for lipid synthesis and understanding of Hilsa defense mechanisms, respectively.

Microsatellite marker set for genetic diversity assessment of primitive Chitala chitala (Hamilton, 1822) derived through SMRT sequencing technology.

In present study, single molecule-real time sequencing technology was used to obtain a validated set of microsatellite markers for application in population genetics of the primitive fish, Chitala chitala. Assembly of circular consensus sequencing reads resulted into 1164 sequences which contained 2005 repetitive motifs. A total of 100 sequences were used for primer designing and amplification yielded a set of 28 validated polymorphic markers. These loci were used to genotype n = 72 samples from three distant riverine populations of India, namely Son, Satluj and Brahmaputra, for determining intraspecific genetic variation. The microsatellite loci exhibited high level of polymorphism with PIC values ranging from 0.281 to 0.901. The genetic parameters revealed that mean heterozygosity ranged from 0.6802 to 0.6826 and the populations were found to be genetically diverse (Fst 0.03-0.06). This indicated the potential application of these microsatellite marker set that can used for stock characterization of C. chitala, in the wild. These newly developed loci were assayed for cross transferability in another notopterid fish, Notopterus notopterus.

Molecular and morphological evidences resolve taxonomic ambiguity between Systomus sarana sarana (Hamilton, 1822) and S. sarana subnasutus (Valenciennes) and suggest elevating them into distinct species.

Taxonomic ambiguity exists in genus Systomus and recently many new species were described under this genus. Systomus sarana subnasutus is considered a valid subspecies of S. sarana sarana although revisions have been done by some researchers. We employed a combination of morpho-meristics and molecular tools (Cytochrome c oxidase I, 16S and Cytochrome b genes of mitochondrial genome) to resolve the two species. Three morpho-meristic characters, head length/maxillary barbel length (HL/MxBL), Lateral Line Scales (LLSs) as well as two truss-based characters, had discernible variation between the two taxa. The sequence analysis (2353 nucleotides) depicted a separate clad of S. sarana subnasutus with high bootstrap support. The findings from combined use of morphology, meristics and mitogenes were concordant. The corroborative results suggest the possibility of two different species. The results suggest to adopt suitable management measures, accordingly.

Characterization of threatened endemic fish Osteobrama belangeri (Valenciennes, 1844) and related species from North-East India based on morphological and molecular analysis.

Four species of the genus Osteobrama collected from five different sampling sites of Chindwin and Barak river basin of North-East India, namely O. belangeri, O. cotio, O. cunma and O. feae, were characterized. Meristic study showed differences in anal fin rays count and lateral line scales. Morphometric analysis revealed significant differences among Osteobrama species. In Truss analysis, a clear pattern of differentiation was observed among the four species with discriminant function analysis assigning 100% correctly to the particular species. In molecular analysis, four Osteobrama species collected were barcoded with COI and 16S rRNA sequences and phylogenetically these four species formed two distinct clusters, O. belangeri form one separate cluster, from the other three species i.e. O. cotio, O. cunma and O. feae. High-resolution clusters generated (NJ trees) aided the groupings of species corresponding to their genera and families which are in confirmation to the values generated by COI Automatic Barcode Gap Discovery bioinformatics platform.

Adequacy of percutaneous non-targeted liver biopsy under real-time ultrasound guidance when comparing the Biopince™ and Achieve™ biopsy needle.

OBJECTIVE: The purpose of this study was to compare the adequacy rates of percutaneous liver biopsies, in parenchymal liver disease, using the BiopinceTM (Argon Medical, Texas, TX, ) 16G and AchieveTM (Carefusion, Illinois, IL, USA) 18G biopsy needles in relation to the Royal College of Pathologists guidelines and to assess risk of complications. METHODS: Data for all percutaneous non-targeted "medical" liver biopsies using the Biopince 16G and Achieve 18G biopsy needles were collected retrospectively over a 2-year period. Total biopsy core length and number of portal tracts was recorded along with adequacy of biopsy as assessed according to Royal College of Pathologists criteria. RESULTS: In total, 194 percutaneous liver biopsies met the inclusion criteria; 53 using the Biopince needle and 141 using the Achieve needle. The mean total core length was 23 mm (SD 4.1) and 20 mm (SD 6.8) for the Biopince and Achieve needles, respectively (p = 0.0005). The mean number of portal tracts was 11 (SD 4.2) and 7 (SD 3.4) for the Biopince and Achieve needles, respectively (p < 0.0001). An adequate biopsy was obtained in 15 (31.3%) and 1 (1.3%) case using the Biopince and Achieve needles, respectively (p < 0.001). Compromised biopsies were obtained in 32 (66.7%) and 39 (50.6%) cases using the Biopince and Achieve needles, respectively. Inadequate biopsies were obtained in 1 (2%) and 37 (48.1%) cases using the Biopince and Achieve needles, respectively. CONCLUSION: The Biopince 16G needle, when compared with the Achieve 18G needle, acquires a significantly greater total core length and number of portal tracts with significantly improved adequacy rates. There were no major complications associated with its use. Advances in knowledge: The Biopince 16G needle achieves significantly better specimen adequacy, when compared with the Achieve 18G needle and with no added major complications associated with its use.

Genetic divergence in natural and farm populations of Pengba fish, Osteobrama belangeri (Valenciennes, 1844), an endemic fish of North-East India derived from mtDNA ATPase 6/8 gene.

Pengba fish, Osteobrama belangeri is a freshwater inhabitant, highly endemic, threatened and economically important minor carp for its food value. In the present investigation, population structure of O. belangeri was examined using mitochondrial ATPase 6/8 gene from geographically distinct locations along the Indo-Burma biodiversity hotspot. A total of 80 individuals were collected belonging to natural and farm populations. The hierarchical analysis of molecular variance and conventional Fst values (0.825 in ATPase 6/8, p < .05) indicated significant genetic structure among populations. The result showed that ATPase 6/8 genes are potential marker in determining the genetic divergence between natural and farm populations of O. belangeri from North-East India.

The complete mitochondrial genome of olive barb, Systomus sarana sarana (Hamilton, 1822) and its phylogenetic status.

Systomus sarana sarana, commonly known as olive barb, is an important food and ornamental fish species with wide distribution in South Asia. Here, the complete mitogenome was sequenced on HiSeq 2500. With 16,590 nucleotides, the base composition was 32.9% (A), 26% (C), 15.4% (G) and 25.7% (T), comparable with other carps. The clustering pattern depicted the monophyly of S. sarana sarana with sister cyprinids.

Expression profile and in silico characterization of novel RTF2h gene under oxidative stress in Indian catfish, Clarias magur (Hamilton 1822).

During the investigation of genes involved in the hypoxia tolerance, novel transcript, Replication Termination Factor 2 homologue (RTF2h), was found to be differentially expressed in brain of Clarias magur (previous name, C. batrachus) whose function was still undefined. Thus, present study was aimed to examine the transcriptional response of novel RTF2h gene, for its possible involvement in hypoxia tolerance in C. magur. Novel transcripts expressed under hypoxic stress were identified from ESTs obtained from SSH libraries of C. magur. Homology analysis of novel transcript (JK487668) revealed it to have RING superfamily signature and was closely related with RTF2 homologue. To characterize the expression pattern of CmRTF2h gene in different tissues of C. magur, qRT-PCR analysis was performed which showed significant increased expression, in spleen following short-term hypoxia exposure (12 H; 2.33-fold), while after long-term hypoxia exposure, significant up-regulation was found three tissues: in spleen (6.57-fold), liver (2.31-fold) and head kidney (2.99-fold) and was down-regulated in brain (3.52-fold). Further, the consensus sequence, obtained from SSH EST sequence and transcripts from hypoxia induced transcriptome data, through multiple sequence alignments, homology modeling and phylogentic analysis together, confirmed it as a novel CmRTF2h gene. In-silico protein-protein interaction and docking studies suggested its closely related function to that of RTF2. The present study reports the expression pattern of CmRTF2h under hypoxia. The up-regulated expression of CmRTF2h under hypoxic conditions may contribute to defense mechanism against induced DNA damage, which in turn may of adaptive significance for hypoxia tolerance in C. magur.

Population genetic structure of Macrobrachium rosenbergii (Palaemonidae) from Indian waters using mitochondrial ATPase 6/8 gene.

Macrobrachium rosenbergii, giant freshwater prawn, is one of the most commercially important crustaceans. In the present study, primers for ATPase 6/8 region of mt-DNA were designed and successfully amplified (827 bp) in the species. The nucleotide variation in ATPase 6/8 gene revealed the population structuring in natural populations of M. rosenbergii in Indian waters. A total of 35 haplotypes were observed in 93 individuals collected from different locations. Low nucleotide diversity and high haplotype diversity were noticed for the ATPase 6/8 gene. Significant pairwise FST and, haplotype network indicated occurrence of distinct populations. Observed mismatch distribution and Tajima's D test suggested demographical stability of giant freshwater prawn. The genetic stock structure revealed in this study will be helpful for conservation and management of stocks of M. rosenbergii in Indian waters.

Complete mitochondrial genome of threatened mahseer Tor tor (Hamilton 1822) and its phylogenetic relationship within Cyprinidae family.

The mahseers (Tor, Neolissochilus and Naziritor) are an important group of fishes endemic to Asia with the conservation status of most species evaluated as threatened. Conservation plans to revive these declining wild populations are hindered by unstable taxonomy. Molecular phylogeny studies with mitochondrial genome have been successfully used to reconstruct the phylogenetic tree and to resolve taxonomic ambiguity. In the present study, complete mitochondrial genome of Tor tor has been sequenced using ion torrent next-generation sequencing platform with coverage of more than 1000 x. Comparative mitogenome analysis shows higher divergence value at ND1 gene than COI gene. Further, occurrence of a distinct genetic lineage of T. tor is revealed. The phylogenetic relationship among mahseer group has been defined as Neolissochilus hexagonolepis ((T. sinensis (T. putitora, T. tor), (T. khudree, T. tambroides)).

De novo development and characterization of polymorphic microsatellite markers in a schilbid catfish, Silonia silondia (Hamilton, 1822) and their validation for population genetic studies.

The stock characterization of wild populations of Silonia silondia is important for its scientific management. At present, the information on genetic parameters of S. silondia is very limited. The species-specific microsatellite markers were developed in current study. The validated markers were used to genotype individuals from four distant rivers. To develop de novo microsatellite loci, an enriched genomic library was constructed for S. silondia using affinity-capture approach. The markers were validated for utility in population genetics. A total number of 76 individuals from four natural riverine populations were used to generate data for population analysis. The screening of isolated repeat sequences yielded eleven novel polymorphic microsatellite loci. The microsatellite loci exhibited high level of polymorphism, with 6-24 alleles per locus and the PIC value ranged from 0.604 to 0.927. The observed (Ho) and expected (He) heterozygosities ranged from 0.081 to 0.84 and 0.66 to 0.938, respectively. The AMOVA analysis indicated significant genetic differentiation among riverine populations (overall FST = 0.075; P < 0.0001) with maximum variation (92.5%) within populations. Cross-priming assessment revealed successful amplification (35-38 %) of heterologous loci in four related species viz. Clupisoma garua, C. taakree, Ailia coila and Eutropiichthys vacha. The results demonstrated that these de novo polymorphic microsatellite loci are promising for population genetic variation and diversity studies in S. silondia. Cross-priming results indicated that these primers can help to get polymorphic microsatellite loci in the related catfish species of family Schilbidae.

Genetic characterization of Silond catfish, Silonia silondia (Hamilton, 1822) inferred from two mitochondrial markers.

Silonia silondia is a commercially important food fish. Samples collected through commercial catches from four rivers in India are described by sequence analysis of two molecular markers. Cytochrome b (1140 bp) and ATPase 6/8 (842 bp) genes were analyzed, which represented high level of genetic differentiation within populations of S. silondia. The sequence alignments of cytochrome b and ATPase 6/8 genes revealed 13 and 11 different haplotypes, respectively. The sequences of both the mitochondrial regions revealed high haplotype and low nucleotide diversities. The patterns of genetic diversity and haplotype networks clearly indicated two distinct mitochondrial lineages, however, haplotypes from both the lineages were not specifically assigned to any population. The results confirm the utility of molecular markers generating baseline information, useful for planning effective strategies for conservation, management and sustainability of Silond catfish fishery.