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Introduction. Fish can sometimes be contaminated with several highly toxic substances at once, e.g. heavy metals, pesticides, and preservatives. In this regard, it is essential to determine the presence of these harmful chemicals in fish products. The research objective was to analyze the level of organochlorine pesticide residues and other toxic substances in Tenualosa ilisha L. Study objects and methods. The study featured organochlorine pesticide residues and other toxic substances in raw and cooked samples of fresh and salted T. ilisha, which is a popular dish in Northeast India, especially in the state of Tripura. The analysis involved tests for formaldehyde, pesticides, and heavy metals. Formaldehyde content was estimated using high-performance liquid chromatography, pesticides content – by low-pressure gas chromatography/tandem mass spectrometry, and heavy metals – by inductively coupled plasma/mass spectrometry. Results and discussion. The salted samples had a high content of formaldehyde, though it remained within the normal range. Both fresh and salted samples demonstrated high concentrations of heavy metals such as zinc, copper, and selenium. The salted sample appeared to have a high content of toxic organochlorine pesticide residues. Frying and boiling of fresh and salted fish decreased formaldehyde and organochlorine pesticide residue contents but did not reduce heavy metal content. Conclusion. T. ilisha was found to be quite safe for human health.

Fresh and salted Tenualosa ilisha is very popular among the common people of Tripura, North-eastern part of India. In the present study, nutritional value of fresh and salted T. ilisha and the effects of different cooking methods such as boiling and frying on them were evaluated. Significant differences were detected in proximate composition as well as in mineral, amino acid and fatty acid content. The increased amount of protein, ash, dry matter and mineral content was observed in salted T. ilisha but reverse was observed in case of amino acid and fatty acid content. Fried sample of both fresh and salted T. ilisha contained more amount of protein, fat, dry matter, ash, minerals and fatty acids than the boiled fish which play an important role in human health. In conclusion, frying process for preparation of fish is found to be good for cooking.

Despite different approaches used to assign the risk scores for missing information in productivity susceptibility analysis (PSA)—a widely used semi-quantitative risk assessment tool for target and non-target fisheries stocks—for the selected attributes of a given species, no formal comparison has been made between scoring approaches in terms of how well they can predict species vulnerability. The present study evaluated the PSA findings of 21 bycatch stocks of the Hilsa (Tenualosa ilisha) gillnet fishery of Bangladesh using two different scoring approaches (the conservative scoring approach, CSA, and the alternative scoring approach, ASA) to determine the most reliable approach to minimize false estimates of species vulnerability. Our analysis revealed that the V scores increased by 0.0−0.20 with a mean value of 0.09 for 21 selected bycatches when CSA was applied. The inconsistency between the vulnerability (V)-score-suggested fishing status (V ≤ 1.8 = underfishing, V &gt, 1.8 = overfishing) and the fishing status defined by exploitation rate (E &gt, 0.5 = overfishing, E &lt, 0.5 = underfishing) were 38.1% and 19.0% under CSA and ASA, respectively. Likewise, the consistency between the V-score-suggested fishing status and fishers’ perceived catch trends was found to be higher when using ASA than when using CSA. Our analysis suggests that CSA could overestimate species vulnerability. Therefore, ASA is more reliable than CSA in PSA, which may increase the confidence of fisheries stakeholders in PSA.

Hilsa, Tenualosa ilisha is a highly prestigious fish for esteemed delicious taste, high market demand and price. It forms an important fishery of funnel-shaped 72 km long Narmada Estuary. Rapid decline in hilsa catch has been recorded in the Narmada Estuary over last few decades. Hilsa catch was recorded 5180 ton in 2006–07 that reduced to only 419 ton in 2014–15. Pre-impoundment of dam showed that T. ilisha contributed to the tune of 977.1 to 3727 ton from 1974–75 to 1982–83 and the highest catch of hilsa was 15319 ton during 1993–94. Sardar Sarovar Dam started functional in the year 1994 which has impacted natural water flow of the river and resulted in a reduction of freshwater availability in the estuary; the development of sand bars at the mouth of the estuary also reduced the tidal ingress into the system; low depth, loss of breeding, nursery and feeding grounds, over fishing may be the most important factors affecting hilsa fishery in Narmada estuary. Catching of juvenile hilsa during winter by ‘Golava’ net (small meshed bag net) also led to a rapid decline in hilsa catch. To maintain the sustainable yield of hilsa, selective fishing and control of juvenile catch are the prerequisites along with maintaining regular flow from the dam.

Objective Hilsa shad (Tenualosa ilisha), is a popular fish of Bangladesh belonging to the Clupeidae family. An anadromous species, like the salmon and many other migratory fish, it is a unique species that lives in the sea and travels to freshwater rivers for spawning. During its entire life, Tenualosa ilisha migrates both from sea to freshwater and vice versa. Data description The genome of Tenualosa ilisha collected from the river Padma of Rajshahi, Bangladesh has been sequenced and its de novo hybrid assembly and structural annotations are being reported here. Illumina and PacBio sequencing platforms were used for high depth sequencing and the draft genome assembly was found to be 816 MB with N50 size of 188 kb. MAKER gene annotation tool predicted 31,254 gene models. Benchmarking Universal Single-Copy Orthologs refer 95% completeness of the assembled genome.

In this study age, growth and maturity of Hilsa shad in Khuzestan province were analyzed. 394 number of fishes from marine habitat (Lifeh-Boseif), estuaries (Bahmanshir and Arvand) and rivers (Bahmanshir and Karoon) from February 2014 to September 2014 were collected using commercial fishing with gill net. Total length and wet weight of each fish were measured with precision of 1 cm and 1 gram. Sagittal otoliths were extracted for age determination of the fish. Since the otoliths were fragile, they were sectioned by polishing with sandpapers 800, 1500 and 2000. Then abdominal cavity of each sample were opened for determining sex and maturity stage. Growth parameters were calculated using von Bertalanffy growth function (L_∞=58.365, K=0.26, t0=-0.16). Phi-prime constant was obtained 2.95. Length and age at first maturity were obtained 27.32cm and 2.4 g respectively using logistic model to fit a and b parameters with observed data in spawning season.

In this research, histological changes of gill and kidney, as a basic and important organ in osmoregulation, during migration from Musa creek to Karun and Bahmanshir Rivers was studied. Ten fish from each station of Persian Gulf, Karun and Bahmanshir with similarity in biometric of size and weight were collected. After fixation in Bouin's solutions, routine procedure of tissue preparation was done and 6 μm sections stained with Hematoxylin and Eosin, studied by optical microscope equipped with a daynolit lenses. The greatest number and area of chloride cells were seen in sea samples but they decreased during migration to Karun and Bahmanshir Rivers (p0.05). In kidney, during migration from the sea to the river, the diameter of proximal and distal lumen increased. But in Karun samples, diameter of lumen of distal tubules were higher than others station. Also, there was no significant difference in other tubule between in Karun and Bahmanshir samples. Therefore according to this study, gill and kidney have active participation in osmoregulation. This fish can be a good model for study of osmoregulation in different salinities because of adaptation and response to different environmental salinities in gill that associated with histologic changes.

This research was conducted for studying of biological parameters of Tenualosa ilisha on spawning and post spawning time. For this reason, 60 fish were captured through three months, on September- fresh water (Karoon river in Khorramshahr) (1st station), September marine water (Hendijan coasts) (2nd station), October-marine water (3rd station) and November-marine water (4th station). Biological parameters, GSI and gonad histological study was performed. The results showed the highest total length, total weight and gonad weight were seen in fish were captured from 1st station which has a significant different with other fishes (p

Information on the genetic structure of fish populations is useful for identification of stocks, management for sustainable exploitation and preservation of genetic diversity. The most important objective in population genetics is discrimination between populations within their distribution areas. The invention of polymerase chain reaction has created new possibilities for exploration of these differences in fish populations. One of these PCRbased methods is Random Amplified Polymorphic DNA (RAPD) which uses short oligonucleotide primers of arbitrary sequences to amplify discrete regions of the genome. The most important features of this method are: obtaining a large number of polymorphic DNA bands using tiny amounts of DNA without necessity of cloning or previous knowledge of DNA sequence. Ilisha shad (Tenualosa ilisha) which is locally known as Soboor is an anadromous fish living in sea shores, estuaries and downstream of rivers and migrate to upstream for spawning. The aim of this research was to study genetic structure of soboor in Khuzestan waters, including Karoon, Arvadrood and Bahmashir rivers, Persian Gulf (Sea) as well as Iraqi samples (caught from Shat-Al-Arab river), by using RAPD technique. For this purpose, fifteen random decamer primers were initially applied on DNA samples of 4 individuals from each region. After optimizing PCR condition, nine primers with best results were selected from which 58 polymorphic loci were obtained on 60 specimens (12 specimens from each geographical region). RAPD data were obtained by scoring 1 and 0 for presence or absence of polymorphic bands, respectively. RAPDPLOT, RAPDDIST and POPGENE computer Software were used to analyze the RAPD data. Canonical discriminant analysis was deployed for statistical analysis of the data. Maximum and minimum genetic distances were found between samples from Iraq and Sea (0.2870) and Arvandrood and Bahmanshir (0.1042), respectively. The UPGMA dendrogram showed that the samples from Karoon and Sea form a clade whereas samples from Iraq, Arvandrood and Bahmanshir rivers form another clade suggesting the hypothesis that there are two Iranian and Iraqi populations of this species and these fish select their own specific river for spawning. According to this hypothesis the specimens from Sea would destine Karoon as their spawning river. On the other hand, two other separate groups could be corresponded to Tigris and Euphrate rivers in Iraq. Moreover, canonical discriminant analysis indicates that samples from four geographical regions are statistically different from each other and high correlation among data was found within each region (P

Some aspects of the reproductive biology of Hilsa Shad, Tenualosa ilisha from the Persian Gulf and rivers of Khouzestan Province of Iran were analyzed. A total of 485 fish were sampled by gillnet from landing center of Arvand (AR) and Bahmanshir (BR) rivers during period of April 2010 to September 2010. Reproductive characteristic of T. ilisha showed that sex ratio is M:F=1:2, in PG, AR and BR. This means that females predominate than males. Monthly variations in Gonadosomatic Index (GSI) of both sexes were quite apparent. In PG, maximum values were recorded in April for male and female. In AR and BR, maximum values were recorded in June and May for male and female, respectively. Changes in GSI indices are considered as a proof that maturation season in AR and BR is started from March and spawning is started from April to July in AR and BR is started from March to August. The Length - Weight relationship was measured for PG as W= 1.459L^2.687, AR and BR as W=2.189L^3.166 and W=1.840L^2.937, respectively.

The hilsa shad, Tenualosa ilisha (Clupeidae, Clupeiformes) is an important anadromous clupeid species from the Western division of the Indo-Pacific region. It constitutes the largest single fishable species in Bangladesh. Information on genetic variability and population structure is very important for both management and conservation purposes. Past reports on the population structure of T. ilisha involving morphometric, allozyme and RAPD analyses are contradictory. We examined genetic variability and divergence in two riverine (the Jamuna and the Meghna), two estuarine (Kuakata and Sundarbans) and one marine (Cox's Bazar) populations of T. ilisha by applying PCR-RFLP analysis of the mtDNA D-loop region. The amplified PCR products were restricted with four restriction enzymes namely, XbaI, EcoRI, EcoRV, and HaeIII. High levels of haplotype and gene diversity within and significant differentiations among, populations of T. ilisha were observed in this study. Significant F(ST) values indicated differentiation among the river, estuary and marine populations. The UPGMA dendrogram based on genetic distance resulted in two major clusters, although, these were subsequently divided into three, corresponding to the riverine, estuarine and marine populations. The study underlines the usefulness of RFLP of mtDNA D-loop region as molecular markers, and detected at least two differentiated populations of T. ilisha in Bangladesh waters.

The genetic structure of Hilsa Shad Tenualosa ilisha in Khouzestan waters including Karoon, Arvandrood and Bahmanshir Rivers as well as Persian Gulf was studied using RAPD technique. After optimizing PCR condition, nine RAPD primers were selected from which 58 polymorphic loci were obtained on 12 specimens from each geographical region (A total of 48 specimens). RAPDPLOT, RAPDDIST and POPGENE computer software were used to analyze the RAPD data. Canonical discriminant analysis was deployed for statistical assessment of the RAPD data. Maximum and minimum genetic distances were found between samples from Arvandrood River and Persian Gulf (0.1987) and Arvandrood and Bahmanshir Rivers (0.0852), respectively. The UPGMA dendrogram showed that the samples from Karoon River and Persian Gulf form one group and samples from Arvandrood and Bahmanshir Rivers form another suggesting the hypothesis that there are Iranian and Iraqi populations of the species that chose their own specific rivers for spawning. According to this hypothesis, the specimens from Persian Gulf chose Karoon as their spawning river. Other populations migrate to Tigris and Euphrates Rivers in Iraq.

Using length frequency information on Tenualosa ilisha catch in the coastal waters of Khouzestan Province (Abadan and Hendijan), we estimated growth parameters of the species. The data were composed of the total length measurement of around 10071 specimens caught in Abadan and 4032 specimens caught in Hendijan waters. The catches conducted monthly during the year 2005 using gill net with a mesh size of 8-9.5 centimeters.

An investigation was conducted to know the freshness quality and associated post-harvest loss of hilsa, if any, transported to Mymensingh from the major landing centers through Cox’s Bazar-Chittagong (route A) and Barguna-Chandpur (route B) routes for a period of July to October 2012. The average environmental temperature of the wholesale and retail markets was 30.7 °C and 30.6 °C where the body temperature of hilsa was 4.5 °C (route A) and 4.7 °C (route B), respectively. The Freshness quality of hilsa was assessed using sensory defects points (DPs) that eventually gave rise to numerical values ‘1’ being the freshest and ‘5’ being the worst quality. The DPs of hilsa were found 2.0, which reveal that the fishes were in excellent conditions, i.e., there was no significant post-harvest loss even during retail sale. DPs on arrival and at wholesale in July, September and October were significantly different after auction and during retail sale (p

This study was carried out on age and growth of hilsa shad, Tenualosa ilisha in river Tentulia in Bhola district using monthly samples from January to December 2009 by checking annual rings or growth checks on hard parts. Age and growth of T. ilisha got progressed by direct fit of length frequency data both to standard and to modified von Bertalanffy growth models with ELEFAN I procedure where the predicted maximum total length were (TL ∞ ) 41.88 cm for male and 52.40 cm for female. Powell-Wetherall procedure gave an initial asymptotic total length (TL ∞ ) for both male and female 40.42 cm, 50.61 cm respectively. The values of Z/K were 3.362 for male and 2.626 for female. The growth co-efficient (K) was obtained as 1.40 year -1 for male and 1.00 year -1 for female. The von Bertalanffy growth equations in terms of body weight (BW) for both male and female were BW t =799.26[1-exp{-1.40(t+0.002)}] 3 and BW t =1717.82[1-exp{-0.99(t+0.013)}] 3 respectively. The length-weight relationship for both sexes were BW=0.0101 TL 3.02 for male and BW=0.0086 TL 3.08 for female. The value of coefficient of determination (R 2 ) was estimated for both male and female species were 0.969 and 0.968.

During 12 months of sampling, from 17 stations, 327 specimens of Soboor fish Tenualosa ilisha, including 120 females, 113 males and 86 immature were caught. Total length (TL) of the fishes was 120-500mm. Maximum diameters of soboor ova 0.795mm and the ova with diameter more than 0.7 mm released at one spawning round. Temporal and spatial distribution of ova diameter corresponding to GSI changes showed that ova with diameters between 0.64 to 0.795 mm released spontaneously in many rounds along fish migration route during its spawning season. The results indicate that the spawning of soboor begins upon its entering to Bahmanshir and Arvand Rivers on April and continued up to Shushtar and Dezful cities on September where their migration route and season are ended.

Iranian Fisheries Science Research Institute Published

Ecological characteristics a Barbus grypus, B. sharpoyi, Capoeta trutta, Mugil abu, Tenualosa ilisha and Johnius belangerii, occurring in Zohre River were studied, among fresh water fishes, B. grypus showed versatility in its habitats, thus occurring frequently in the river. In contrast B. sharpeyi, a stenohaline fish, was found only in a limited section of river reaching to the estuary. C. trutta even so being stenohaline, covered a wider range of the river in comparison with B. sharpeyi thus showing more compatibility with varying phsico-chemical environments. Amongst anadromous fishes, Mugli abu covered a greater part of the river and it seems likely the fish spawns two times a year. The occurrence of this species shows a peak in summer and winter. On the contrary, T. ilisba occurs only on spring and summer in the river, evidently for spawning. Apparently, the preferred environment for the Spawning of the latter ought to be alkaline and have low salinity and high oxygen content accompanied by muddy bottom, slow water current and high depth. The J. belangerii showed the least occurrence and mainly caught in the estuary in Autumn.

Tenualosa ilisha (Hamilton) is a valuable migratory fish belonging to the family Clupeidae and it is distributed in a wide area from the Persian Gulf to coasts of Pakistan and China’s southern sea. The aim of the present study was to investigate the changes occurring in innate immunity parameters during upstream migration and comparing them to those during post spawning. Sixty mature female hilsa shad were obtained using gill net from Karoon River in Khorramshahr during the spawning period (July, August and September 2014) and Hendijan coasts along the Persian Gulf coasts during post spawning period (October, November and December 2014). Immediately, blood samples were collected from the peduncle vein and then parameters including WBC (White Blood Cell) count, Differential WBC Count, plasma lysozyme content and C3 and C4 complement activity were determined. Based on the results, the levels of WBC, lysozyme and C3 during the spawning period were lower than those recorded during post spawning period. However, C4 levels were higher during spawning (p