Journal of Fisheries (University of Rajshahi)
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Depuration kinetics of potentially toxic metals (Hg, Co and Cr) in Perna viridis: Implications for biomonitoring, environmental management, and planetary health
Get PDFThis study aims to study the depuration kinetics of mercury (Hg), cobalt (Co), and chromium (Cr) in the soft tissues of the green-lipped mussel Perna viridis, transplanted from one polluted site (Kg. Pasir Puteh) to two relatively unpolluted sites (Sungai Belungkor and Kg. Sungai Melayu). The effectiveness of P. viridis as a biomonitor for heavy metal contamination was assessed by monitoring the reduction in metal concentrations over a six-week period. The results revealed that Hg exhibited the highest depuration rates, with reductions exceeding 95% at both sites, while Co and Cr showed slower depuration rates, with significant site-specific variations. Health risk assessments, including estimated daily intake, target hazard quotient, and estimated weekly intake, indicated a substantial decrease in potential risks associated with seafood consumption as a result of the depuration process. These findings underscore the importance of considering environmental conditions when interpreting depuration data, highlight the role of P. viridis in supporting sustainable environmental management practices, and connect the health of marine ecosystems to broader planetary health and global sustainability goals, including the United Nations Sustainable Development Goals
Studies on sex ratio, condition factor and patterns of phenotypic estimation in stock identification of snow trout, Schizothorax esocinus Heckel, 1838 inhabiting the colder Indian Himalayan region
Get PDFSchizothorax esocinus, a nutrient-rich food fish offered in Asian countries, is rapidly declining due to severe fishing pressure and pollution in its wild environment, requiring active conservation strategies. Our study examined 196 specimens to elucidate critical biological parameters including sex ratio, length-weight relationships (LWRs), Fulton's condition factor (K) and morphometric-meristic parameters. The general sex ratio was not substantially departed from the predicted value of 1 : 1, with the exception for the month of May, where χ2 = 4.15 which is greater than the calculated value of 3.84. The correlation between the length and weight was reported as Log W = 0.134209 + 2.5218 log L for males, Log W = 0.19173 + 2.6751 log L for females and Log W = 0.162116 + 2.594 for combined sexes. Schizothorax esocinus demonstrated a negative allometric growth as indicated by the allometric parameter b for the LWR. The two sexes showed no significant differences in morphometric measures. So, this study included combined-sex regression analysis. These comprehensive findings highlight the critical need for conservation efforts in India and neighbouring countries to preserve this valuable fish stock for future generations
Notes on some newly recorded fish from Andhra Pradesh coast, India
Get PDFEleven fish species, namely Heniochus singularius Smith & Radcliffe, 1911; Entomacrodus vermiculatus (Valenciennes, 1836); Pomacentrus similis Allen, 1991; Myripristis berndti Jordan & Evermann, 1903; Myripristis seychellensis Cuvier, 1829; Sargocentron cornutum (Bleeker, 1854); Thalassoma lunare (Linnaeus, 1758); Pardachirus pavoninus (Lacepède, 1802); Paraplotosus albilabris (Valenciennes, 1840); Canthigaster papua (Bleeker, 1848), have been documented for the first time in Andhra Pradesh state of India associated with artificial reef and rocky shoreline habitats. Additionally, E. thalassinus has been recorded for the first time in India from this study. The study provides detailed descriptions of the diagnostic characteristics and distribution of these ten species. These findings highlight the richness of fish fauna along the Andhra Pradesh coastline of India
Genetic differentiation and heavy metal pollution influence on horseshoe crab Tachypleus gigas populations in Peninsular Malaysia: A comprehensive allozyme analysis
Get PDFThis study aimed study the genetic diversity and differentiation of Asian horseshoe crab Tachypleus gigas (Müller, 1785) populations across three distinct locations in Peninsular Malaysia: Kampung Pasir Puteh (KPPuteh), Kuala Sungai Ayam (KSAyam), and Kampung Pulau Sayak (KPSayak). A total of 28 individuals were collected, and their genetic structure was analyzed using starch gel electrophoresis. The study employed multiple buffer systems optimized for separating 20 different enzymes, each contributing to understanding the genetic variability within and between populations. The findings of this study, which revealed significant genetic differentiation, particularly between populations in polluted and less impacted environments, as reflected by high FST values and distinct clustering in the UPGMA dendrogram, are of paramount importance. The results indicate that environmental factors, especially metal-polluted sites at KPPuteh and KSAyam, have played a critical role in shaping the genetic structure of these populations. Populations from the two polluted sites, exhibited higher genetic diversity and greater deviations from Hardy–Weinberg equilibrium, suggesting localized selection pressures. Conversely, from a less polluted site, the unpolluted site at KPSayak population showed lower genetic variability and was genetically distinct from the others. These findings underscore the importance of considering environmental influences in conservation strategies for T. gigas, highlighting the need for site-specific management to preserve genetic diversity and ensure long-term survival of the species
A bibliometric analysis of research on fish and floristic diversity: Trends and themes
Get PDFResearch on the relationship between fish and floristic diversity has been limited by narrow scopes, inconsistent methodologies, and geographic biases, resulting in fragmented insights. This study presents a comprehensive bibliometric analysis on the relationship between fish diversity and floristic diversity, spanning nearly six decades from 1965 to 2024. Using the Scopus database, 47 publications were identified based on the presence of the keywords "fish" and "floristic diversity" in article titles, abstracts, and keywords. The analysis reveals a gradual increase in publications over time, with notable peaks corresponding to heightened awareness of biodiversity conservation. The research themes identified include habitat provision, ecosystem resilience, impact of environmental change, and the role of invasive species. The study highlights the importance of integrating conservation strategies that protect both fish and plant diversity to maintain ecosystem health and resilience. The findings also point to regional and taxonomic specificity as critical areas for future research, particularly in climate change and habitat alteration. This bibliometric review provides valuable insights into the evolution of this field and identifies gaps and opportunities for further investigation. Therefore, the study underscores the critical interdependence between fish and floristic diversity within ecosystems, a relationship that both natural processes and anthropogenic influences have shaped over time. The findings suggest that conservation efforts must adopt a more integrated approach, recognizing the mutual dependencies between different forms of biodiversity. This approach will be essential for mitigating the adverse effects of human activities on ecosystems and ensuring the long-term sustainability of both fish and plant communities
Stocking density optimisation for gulsha, Mystus cavasius farming in pond under drought prone area of Bangladesh
Get PDFLack of appropriate stocking density is the constraint for aquaculture promotion of a potential species like gulsha, Mystus cavasius in ponds under drought prone area. With a view to addressing this problem, three different densities 98800, 123500 and 148200 gulsha individuals ha–1 were tested under three treatments (T1, T2 and T3) in ponds under Paba Upazila of Rajshahi district, Bangladesh. Treatments were replicated thrice. Hatchery produced gulsha seeds were grown for a period of six months from July – December 2021 with commercial feed containing 35% protein. Water quality and fish growth were monitored fortnightly. Significantly (p < 0.05) lowest value of dissolved oxygen and highest values of carbon di-oxide and ammonia-nitrogen were observed in T3. Significantly lowest values of final weight, weight gain, specific growth rate and survival rate were also observed in T3. However, significantly (p < 0.05) highest yield and cost-benefit ratio were obtained in T2
Ecological impacts on the distribution of Ganges River dolphin (Platanista gangetica) in the lower Gangetic plains and its conservation challenges
Get PDFDespite threatened status, the Ganges River dolphin (Platanista gangetica) received insufficient attention in many habitats including the lower Ganges. In this study, through standardised monitoring programmes, we recorded the population and distribution of the species from a 100-km long stretch of the lower Ganges between January and December 2023. Important ecological parameters (e.g. fish abundance and water quality parameters) were also monitored to understand their effects on dolphin population in the river. Number of Ganges River dolphin varied over time (ANOVA: F11,88 = 10.9, p < 0.001) and space (F8,88 = 24.1, p < 0.001). Maximum number of dolphin was sighted in the month of August; whereas, the minimum was in February. Population of Ganges River dolphin was affected positively by fish abundance (LMM: F = 19.7, p < 0.001) and water transparency (F = 4.4, p = 0.042) and negatively by total dissolved solids (TDS; LMM: F = 13.5, p = 0.001). A range of challenges related to fishermen’s knowledge and attitude towards the Ganges River dolphin were identified. These include lack of awareness, high market demand and price for the species and negative attitude towards the species. Illegally harvested Vulnerable dolphins were sold only to produce dolphin oil to catch another Endangered fish species Clupisoma garua. The results of this study have conservation management applications and implications
Effect of ploidy on growth, fillet composition and colour of large rainbow trout (Oncorhynchus mykiss) in the Black Sea
Get PDFThe purpose of this study was to determine the growth performance and fillet quality parameters of large rainbow trout (Oncorhynchus mykiss) and of different ploidy (diploid-DTS and triploid- TTS) cultured in the Black Sea. This study was carried out in a commercial fish farm in Sinop, Black Sea of Turkey. Triploid groups had a higher weight and a better feed conversion rate than the DTS at the end of the 150-day study. Crude protein and crude fat ratios were respectively higher in the DTS and TTS groups; while ploidy affected the biochemical and fatty acid compositions of the large rainbow trout, it had no effect on the amino acid compositions. The colour of fillets was affected by the crude fat ratio of the fillet. This study indicated that large rainbow trout produced in the Black Sea, regardless of its ploidy, were of high quality, nutritious and healthy for human consumption. Furthermore, it demonstrated yet again that large rainbow trout is of sufficient quality to compete with other salmonid species in the national or international markets
Fishery characteristics, population dynamics and the impacts of the invasive red swamp crayfish (Procambarus clarkii) in the Nile River, Egypt
No full textAlien intrusive species are one of the extreme pressures on biodiversity for their rapid reproduction and adaptation to new environments. Crayfish Procambarus clarkii entered Egyptian freshwater ecosystems at the beginning of 1980's. After many years of negative effects of its introduction onto the Egyptian waters, it became one of the commercially important species. Population parameters of P. clarkii are estimated based on 1355 specimens collected from the Nile off El-Minya during 2019–2020. The isometric growth of the species under the study is confirmed according to the obtained b-value of length–weight relationship (LWR). Annual sex ratio (female : male) was in favour of females with an annual sex ratio 1.44 : 1. The values of growth coefficient (K) and the asymptotic total length (L∞) were assessed for males, females and combined sexes. Using mortality estimates, the exploitation ratio was 0.64 year–1. Investigation of relative yield per recruit (Y'/R) and analysis of relative biomass per recruit (B'/R) for P. clarkii in the Nile off El-Minya provides the highest (Y'/R) at Emax = 0.81 and the E0.5 (utilisation level that preserves the spawner stock biomass at 50% of the virgin spawning biomass) was 0.38. From fisheries management point of view, the current exploitation level should be decreased to that maintain the spawning stock biomass (from 0.64 to 0.38)
Advancing fishing technology education and research: a 65-year legacy at Nha Trang University, Vietnam
Get PDFAs a coastal country, Vietnam relies on marine exploitation for food security and livelihoods. Training human resources to research, exploit, and manage marine resources is an important strategy to maintain rapid and sustainable economic growth and development. Official training in fishing technology at Nha Trang University (NTU) started in 1959. With 65 years of teaching, the unique program only offered at NTU, has made significant contribution to social-economic development in general and sustainable marine fisheries in particular. In this paper, we review the major achievements in teaching and scientific research in fishing technology at NTU as well as highlight the challenges and progress. Over the years, thousands of students have been trained under the fishing technology program and they then have worked all over the country, working in fisheries management, science, and services. Hundreds of research projects and peer-reviewed papers have been conducted and published. Those have supported fishing efficiency, environmentally friendly fishing methods, and effective management. However, the number of fishing technology students has decreased during the past few years because of unfavorable study and working environments where students are often exposed to commercial fishing vessels that frequently operate under rough weather conditions. Despite challenges and difficulties, NTU is determined to maintain the program to support the ocean economic development of the nation