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Fish communities of tropical lakes are commonly predicted by local environmental variables, including depth, temperature, oxygen concentration, and substrate composition. Increasingly, however, lacustrine fish communities are being impacted by invasive species. In the state of Quintana Roo, on the Caribbean versant of the Yucatan Peninsula in Mexico, inland aquaculture production has resulted in the widespread establishment of African tilapia (Oreochromis sp.). However, there are still limited quantitative data on their abundance relative to indigenous species, or their influence on native fish diversity. Here, we quantified the ichthyofauna of six lakes from this region, alongside physical and chemical environmental variables. Overall, we observed that greater dissolved oxygen concentration and shallower depths were associated with the highest fish biodiversity across lakes. Moreover, spatial comparisons additionally highlighted the importance of substrate heterogeneity and lake area as influential in determining native fish community structure. Notably, in all lakes, tilapia were relatively uncommon, comprising less than 3% of all fish captured, and their presence was not a significant predictor of indigenous fish biodiversity. Based on these results, we suggest that tilapia may have strong limitations on their population size, plausibly due to the presence of predatory native fish species, or scarce suitable ecological resources (food, breeding habitat). Conservation-focussed lake-wide management of native species via protection of core habitat characteristics may be key to promoting environmental resistance against negative effects of tilapia regional expansions. [ABSTRACT FROM AUTHOR]

Fish provide an affordable and readily available source of animal protein for human consumption that plays a vital role in maintaining the livelihoods of Bangladeshi people. The study was conducted to evaluate the proximate composition of five different small indigenous fish species (SIS): viz., Glossogobius giuris, Mastacembelus pancalus, Mystus tengra, Heteropneustes fossilis, and Puntius ticto. The samples were collected from the Mathabhanga River. The proximate composition of the studied samples revealed varying proportions of moisture content (68.60 to 79.05%), crude protein (46.22 to 65.99%), crude fat (4.77 to 22.93%), ash content (12.03 to 19.22%), carbohydrate (11.22 to 15.73%), crude fiber (0.09 to 0.25%), whereas the energy value was 374.04 to 444.91Kcal/100g. Among the examined fish species, Glossogobius giuris contained significantly (P< 0.5) higher level of protein content but less amount of lipid content. Addittionally, Puntius ticto showed significantly (P< 0.05) higher lipid, ash and energy contents as compared to others. The results of the study clearly revealed that Glossogobius giuris and Puntius ticto fish species are rich in macronutrients in alliance with the tested fish species. Hence, the research findings suggest that commonly consumed small indigenous fish species (SIS) offer a valuable source of high-quality protein and essential macronutrients. This implies that the consumption of these fish can help alleviate protein and other nutrient deficiency, as well as livelihood security in Bangladesh. Further biochemical and molecular research can be conducted to analyze all the essential nutrients and genetic improvement of the fish. [ABSTRACT FROM AUTHOR]

The small indigenous fish (SIF), having length of about 25 cm is locally available in the small water resources viz. wetlands, canals, streams etc. and affordable to the poor people also. These are important food item as animal protein, vitamins and minerals sources in the diet of human beings. The objective of this review is to investigate the availability and importance of SIF in nutritional security and income generation of the community. Published and unpublished sources were used to obtain appropriate data. This study interprets actual availability of different species of SIFs, capture and culture resources, consumption pattern and marketing channels etc. A literature review was conducted to highlight the research attempt made to enhance the socio-economic condition of rural sector and as a result it offers important guidelines to popularize SIFs for nutritional security. In India a total of 765 native freshwater fish species documented, out of which about 450 are categorized as small indigenous fish species. The maximum diversity of the SIF's has been recorded from the North East region followed by Western Ghat and Central India. Review indicates an ardent need of focused research efforts towards the development and conservation of these fishes before they become extinct. [ABSTRACT FROM AUTHOR]

The translocation of non-indigenous fishes into lowland rives can result in invasive populations establishing and dispersing. Because non-indigenous fishes can cause ecological harm, it is important to understand their trophic relationships and the effects they may have on native fishes. We assessed the trophic ecology of a translocated chub Squalius cephalus population in the River Frome, a lowland chalk stream in Southern England, using bulk stable isotope (δ13C, δ15N) metrics, and compared the results with those derived from indigenous chub populations. The isotopic niche sizes of all fishes in the River Frome were substantially larger in the tidal versus non-tidal site, with the δ13C values suggesting some fish were foraging further downstream of their sampling point in areas that had greater tidal and salinity influences. Inter-specific comparisons of isotopic niches revealed a consistent pattern of similar niche size and overlap between chub and the trophically analogous dace Leuciscus leuciscus. These isotopic relationships between chub and dace were then also apparent in the indigenous populations of these fishes. These results suggest that the colonisation of this lowland river by translocated chub is being facilitated by their isotopic relationships with other fishes that are similar to those observed in their native range. [ABSTRACT FROM AUTHOR]

Black teatfish (Holothuria whitmaei) is a high value sea cucumber that has been listed under the Convention on International Trade of Endangered Species (CITES) Appendix II. The Black teatfish fishery in Torres Strait, Australia, is fished solely by Indigenous Torres Strait Islanders. Black teatfish were closed to fishing in 2003, based on the results of stock surveys and concerns of overexploitation. A stock survey in 2009 found the Black teatfish population had recovered substantially but the fishery was again closed after trial openings exceeded catch limits. In line with a new harvest strategy adopted for the fishery in 2019, we conducted a stock survey in 2019–2020 that suggested the stock had recovered sufficiently to support a sustainable catch limit of 20 t. Empowering Indigenous Torres Strait Islanders to use Island custom alongside western management strategies, contributed to the success of a trial opening in 2021. The combination of a harvest strategy developed in consultation with traditional owners, a rigorous scientific survey and trial opening protocols informed by Island custom, supported the CITES positive Non‐Detriment Finding for the Torres Strait Bêche‐de‐mer Fishery. This is a significant example of the successful recovery and ongoing sustainable management of a depleted sea cucumber population. [ABSTRACT FROM AUTHOR]

Freshwater fish are in a perilous state with more than 30% of species considered critically endangered. Yet significant ecological and methodological complexities constrain our ability to determine how disturbances are impacting native fish communities. We review current methods used to assess the responses of fish communities, especially native fish, to disturbances, with a focus on lakes. These methods include contemporary population surveys, manipulative experimental approaches, paleolimnological approaches and Indigenous Knowledge and social histories. We identify knowledge gaps, such as a lack of baseline data for native fish, an inability to assess the impact of historical disturbances, stressor response dynamics in contemporary multi‐stressor environments, and natural disturbance regimes. Our assessment of the current methods highlights challenges to filling these knowledge gaps using the reviewed methods. We advocate strongly for the implementation of an integrative approach that combines emerging technologies (i.e. molecular‐based techniques in contemporary surveys and paleolimnology) and underutilised knowledge streams (i.e. Indigenous Knowledge and social histories) which should be used in concert with conventional methods. This integrative approach will allow researchers to determine the key drivers of decline and the degree of change, which will enable more informed and successful management actions. [ABSTRACT FROM AUTHOR]

Neoergasilus japonicus, a fish ectoparasite indigenous to eastern and southern Asia, has been introduced to various regions, including Europe and North and South America, where it spreads at an alarming rate. The parasite is not host‐specific. It was also collected from the Vaal‐Orange and Limpopo river systems in South Africa. This report describes the morphology of the wound‐inflecting structures in N. japonicus and relates their morphology to the pathological effect on Tilapia sparrmanii. Host tissue with parasites attached was imbedded in resin for histological sectioning and stained with haematoxylin and eosin. Additional specimens were prepared for scanning electron microscopy. Adult female parasites attach by inserting the hooked tips of the antennae into the epidermis. The maxillulae are minute but have sharp tips. The maxillae have sharp tips on the endopod and brush‐like setae on the exopod. The mandibles are armed with sharp tips. These structures are used to remove the epidermis of the host and brush it into the buccal cavity. Host tissue in the intestine confirms that adult females consume host tissue leaving the dermis exposed to opportunistic diseases. The microscopic size of the parasite prevents casual observation, and its occurrence in Africa is, therefore, probably underreported. [ABSTRACT FROM AUTHOR]

The global ornamental fish trade is expanding in response to increased demand for indigenous fish on the global market, while exogenous carotenoids can improve colouration. The 60‐day trial investigated the effect of carotenoid supplementation, via Artemia, on colouration, growth and immunophysiology of Badis badis (dwarf chameleon fish). Carotenoid was enriched at 40 ppm (T1), 80 ppm (T2) and 120 ppm (T3) and compared with controls, C1 (unenriched) and C2 (oil‐enriched). Fish larvae (average weight 0.12 g) were fed enriched–unenriched Artemia in triplicates (5 × 3) in aquarium tanks (15 L). C1 and T2 had better skin colour (lightness and whiteness) in the posterolateral and caudal fins respectively. The value of redness (a*) in the anterolateral region was higher in T2 and T3 (p < 0.05). The anterolateral red index was higher (p < 0.05) in T2 and T3, whereas in the posterolateral and caudal fins, T1 and T2 were higher (p < 0.05). Compared to C1 and C2, the hue angle in carotenoid groups was found to be low (p < 0.05). No significant change in the growth performance was noticed (p > 0.05). Immune scores such as lysozyme and alkaline protease were highest in T3 (p < 0.05), whereas protease activity was highest in T2 (80 ppm). Stress biomarkers, viz., superoxide dismutase, catalase and malondialdehyde were low in groups fed enriched Artemia (p < 0.05). The integrated biomarker response means and star plot area were lower in the enriched groups (T1–T3), while T2 was the lowest. Overall findings reveal that dietary carotenoid improves the colouration and immune status, but fail to promote growth. Furthermore, 80 ppm enrichment dose improves the overall performance. The findings can help fish keepers improve fish colour and health status through carotenoid supplementation. [ABSTRACT FROM AUTHOR]

Coastal ecosystems of the Mediterranean Sea are among the richest in non‐indigenous species, mostly due to the establishment of species coming from the Red Sea through the Suez Canal. Two herbivorous rabbitfishes, Siganus rivulatus and Siganus luridus, are already invasive in the south‐eastern part of the Mediterranean Sea where they cause ecological damage by overgrazing algae.The early detection and the counting of these non‐indigenous species in the rest of the Mediterranean Sea is thus a major challenge for scientists and ecosystem managers. However, analysing images from divers or remote cameras is a demanding task.Here, a dataset of 31,285 images of Siganus spp. and of six common native fishes to the Mediterranean Sea was built from 40 underwater videos recorded at three reef habitats. A deep learning algorithm was then trained to identify Siganus spp. on images containing the eight Mediterranean species. Finally, the algorithm and a post‐processing filtering were tested with an independent dataset of 2024 images.The model had a recall of 0.92 for the Siganus genus (i.e., two Siganus species combined). After a confidence‐based post‐processing, the recall increased to 0.98 with only 4 out of 272 images of Siganus spp. being misclassified. Accuracy reached a score of 0.61 meaning that experts would have to discard false positives. Images of five native species not present in the training dataset yielded similar false positive rates than species present in the training dataset. Overall, the automatic processing of images by the model and then the checking of putative Siganus images by experts required up to five times less effort than a full processing by experts.The algorithm can help to efficiently detect these two invasive fishes in underwater images to evaluate progress towards conservation objectives and accelerate citizen‐based monitoring of coastal ecosystems. [ABSTRACT FROM AUTHOR]

Present research article deals with fish faunal diversity and their conservation status in Maseh and Khairan streams of Beas River in Kangra district of Himachal Pradesh. Ten fish species were recorded from the streams. Out of which, 6 species viz., Pethia ticto, P. conchonius, Opsarius bendelisis, Mastacembelus armatus, Salmostoma bacaila were common in both the streams, whereas, Barilius vagra was present in Maseh stream and Xenontodon cancila, Crossocheilus latius diplocheilus and Acanthocobitis botia were present in Khairan stream only. All the fish species belongs to Least Concern category as per IUCN. These streams provide refuge to large number of indigenous fish population, but are also undergoing major habitat alterations due to various man-made stressors. So proper conservation of diversity of the region is necessary before it is vanished. [ABSTRACT FROM AUTHOR]

The present study was undertaken in the three locations coming under mid hill areas i.e., Dirang, Chug and Changpa of Dirang block during the year 2015-17 under West Kameng district. This district lying approximately between 91° 30' to 92°40' East longitudes and 26° 54' to 28° 01' North latitudes, with the varying elevation ranging about from 300-4200 meter and covering about 7422 Sq.KM of geographical region accounting for 8.86% of the total area of the state Arunachal Pradesh. An important indigenous fish species i.e Labeo calbasu (Hamilton, 1822) were introduced as a new species in carp polyculture system for species diversification and the study on growth performance and their suitability for culture in mid hill areas of the district West Kameng. The result obtained were found to be very encouraging and on the basis of that it is clear that L. callbasu can be candidate species in carp polyculture system for better profitability in mid-hill areas where the L. rohita (a main component species among IMC) growth is not being found satisfactory due to climatic condition. [ABSTRACT FROM AUTHOR]

The Lancang-Mekong River watershed has extremely high fish biodiversity. With the rapid population growth and economic development in the river basin, fish diversity and fishery resources of this river are experiencing serious threats. Basic biological information on most fish species in the Lancang River, required to improve conservation in this area, is limited. This study aimed to provide new estimates of length-weight relationships (LWRs) by using the linear regression of W = aLb for eight indigenous fish species from the Lancang River, Southwest China. From 2018 to 2021, 534 specimens belonging to 3 families and 8 genera were collected using various types of fishing techniques. Standard length (SL) and body weight (BW) of each specimen were measured to the nearest 0.1 cm and 0.1 g, respectively. This study presents the first public records of LWR parameters of Schizothorax lissolabiatus, Poropuntius huangchuchieni, Tor sinensis, Scaphiodonichthys acanthopterus, Mystacoleucus lepturus, Hemiculterella macrolepis, Glyptothorax lampris, and Schistura porthos. The range of b values for the LWRs was 2.5378–3.1732, and the r2 values for all LWRs estimates ranged from 0.9102 to 0.9952. Intraspecific difference of b values across population and/or season was observed in S. lissolabiatus, T. sinensis, P. huangchuchieni, S. acanthopterus, and M. lepturus. The range of mean condition factor (K) and mean relative weight (Wr) was 0.97–2.39 and 100.29–108.18, respectively. This study updated information for FishBase and provided new record of maximum standard length for five species, namely, S. lissolabiatus, P. huangchuchieni, T. sinensis, S. acanthopterus, and M. lepturus. The findings of this study are essential for the management and conservation of locally indigenous fish and fisheries. [ABSTRACT FROM AUTHOR]

Microplastic (MP) pollution in freshwater environments has drawn considerable attention over the decades due to the risk posed by MPs to the aquatic fauna and human health. In this study, the occurrence of MPs was assessed from the gastrointestinal tracts (GIT) of indigenous fishes from Bhogdoi River, a tributary of River Brahmaputra, northeast hill region, Assam, India. All the fish species (n = 180) analysed showed 100% occurrence of MPs sampled from three stations of River Bhogdoi. A total of 488 microplastic particles were recorded from GIT of fishes collected. The mean abundance of MPs was highest in Station-II (7.64 ± 2.77 numbers individual−1) with lowest in S-I (3.17 ± 0.99 numbers individual−1). The MP size of 100–500 μm, MP shape of fibre (43.33%) and fragments (35.33%), blue colour MPs (26–37%) and polymer type PA (23–30%) were most prevalent in fishes analysed from River Bhogdoi. The mean abundance of MPs was higher in herbivore fishes (8.52 ± 1.22 numbers individual−1) as compared to carnivorous and omnivorous fish species with highest abundance in Labeo rohita (12.11 ± 2.13 numbers individual−1). Fibre and fragments with size range of 100–500 μm were dominant among all the feeding habits. Blue and black colour MPs were abundant among herbivore and carnivore fishes. Fourier transform infrared spectroscopy results confirmed that polyamide and polypropylene were the most abundant MP polymer in the fishes analysed. The present study provides baseline information of MPs in River Bhogdoi, Assam, for its future monitoring and assessment of contaminants. [ABSTRACT FROM AUTHOR]

The River Ganga produces a substantial amount of its fish from small native species, defined here as those with a maximum length of 25 cm. The FiSAT program was utilized to estimate stock assessments of four important small indigenous species from the River Ganga: Johnius coitor, Cabdio morar, Salmostoma bacaila, and Gudusia chapra. Fish samples were collected monthly for a year (April 2020–May 2021) from four predetermined sampling sites along the River Ganga (Farakka, Berhampore, Balagarh, and Tribeni) in West Bengal, India. The estimated exploitation rate for Johnius coitor, Salmostoma bacaila, and Gudusia chapra was relatively lower than the optimum level of 0.5 and considerably lower than Emax values, indicating that their stocks are experiencing low fishing pressure in the region. The FiSAT results indicated that the species Cabdio morar was found to be heavily exploited. The total mortality (Z), natural mortality (M), and fishing mortality (F) rates for all four of the SIF species were examined, and they were contrasted with data from previous studies. On the lower stretch of the River Ganga, all of the fish stocks are optimally exploited (Eopt), except for the species Cabdio morar. The population dynamics of all of the species have been described for the first time on the lower stretch of the River Ganga. According to the findings, all of the fish stocks throughout the lower stretch of River Ganga are optimally exploited (Eopt), except for Cabdio morar. The study also emphasizes the importance of increasing sustainable fishing efforts, focusing on SIFs throughout the lower stretch of the River Ganga in order to safeguard the livelihood and nutritional status of fishermen. [ABSTRACT FROM AUTHOR]

Similar to many freshwater ecosystems, the Laurentian Great Lakes of North America have undergone numerous anthropogenic stressors resulting in considerable loss of biodiversity and habitat. Among Great Lakes fishes, the coregonine sub-family has endured the most extensive declines, including extinction of several species (Coregonus johannae, C. alpenae, and C. kiyi orientalis) and at least 10 instances of local extirpations of other species (C. nigripinnis, C. reighardi, C. zenithicus, C. hoyi, and C. artedi) across all 5 lakes, much of which occurred prior to the 1960s owing to overfishing, interactions with non-indigenous species, and habitat loss. Despite these declines, no federal-, provincial-, or state-mandated actions were ever implemented to conserve coregonine diversity, potentially because so much of the coregonine declines occurred prior to the enactment of federal conservation legislation. Possible explanations for inaction since enactment of that legislation include insufficient data on biological vulnerability or threats, unresolved taxonomy, and limited support from the fishery management agencies and their stakeholders prior to the 2000s. In recent decades, however, several fishery management agencies have undertaken efforts to re-introduce coregonine diversity. These efforts helped lead to development of a science-based framework to restore coregonines that was universally endorsed by fishery managers representing eight U.S. states, four U.S. tribal organizations, and the province of ON, Canada, in May 2018. The basin-wide framework is based on principles of conservation biology and adaptive management. We describe details of its key steps, including planning, restoring, and evaluating, while also describing recent implementation efforts to develop methods, improve available resources, and enhance coordination across the basin. Although our paper describes a regional effort to restore native coregonines, our adaptive-management approach could be used by other multi-agency stakeholders seeking to conserve or restore native fishes. [ABSTRACT FROM AUTHOR]

Understanding the characteristics and conditions that make non-indigenous species (NIS) successful at establishing in recipient communities is a key in determining their potential impacts on native species, as well as to improve management actions such as prevention of future invasions. The round goby (Neogobius melanostomus) is one of the most widespread non-indigenous fish species in the Northern Hemisphere, including the coastal zones of the Baltic Sea. The impacts of round goby in the Baltic Sea are pronounced and multifaceted, yet our knowledge regarding the underlying assembly processes determining its establishment is limited. To overcome this knowledge gap, we applied a trait-based approach to assess the degree of niche overlap and functional (trait) similarity between round goby and native fish species in coastal areas from the Baltic Sea, based on the functional distinctiveness metric. Our results show that round goby is generally quite similar (or not dissimilar) to the native fish of the regional species pool, at least in terms of its overall trait composition. Conversely, round goby demonstrates pronounced differences compared to the native community in its display of parental care and territorial behaviour. Such differences in individual traits could play an important role in round goby's invasion success in the Baltic Sea, including its interactions with native species (e.g. competition). Our results and their potential implications may be highly relevant for conservation and management if integrated within existing risk assessment tools for biological invasions in order to prioritise and enhance the effectiveness of preventative actions towards the expansion of round goby. [ABSTRACT FROM AUTHOR]

Fish in the Volga-Kama River System (the largest river system in Europe) are important as a crucial food source for local populations; fish have the highest trophic level among hydrobionts. The purpose of this research is to describe the diversity of non-indigenous and native fish in the Volga and Kama Rivers, in the European part of Russia. This dataset encompasses data from June 2001 to September 2021 and comprises 1888 records (36,376 individual observations) for littoral and pelagic habitats from 143 sampling sites, representing 52 species from 42 genera in 22 families. The dataset has a Darwin Core standard format and has been fully released in the Global Biodiversity Information Facility (GBIF) under CC-BY 4.0 International license. The data are validated with several international databases such as FishBase, Eschmeyer's Catalog of Fishes, the Barcode of Life Data System, and the SAS.Planet geoinformations system. Newly established populations have been found for several species belonging to the following Actinopteri families: Alosidae, Anguillidae, Cichlidae, Ehiravidae, Gobiidae, Odontobutidae, Syngnathidae, and Xenocyprididae. Therefore, this dataset can be used in the particular taxon species distribution analysis, which are especially important for non-indigenous species. Data set: https://doi.org/10.15468/n8gv7y Dataset License: Creative Commons Attribution (CC-BY) 4.0 International License [ABSTRACT FROM AUTHOR]

Fishes achieving an utmost length of 25-30 cm at maturity and are easily locally found are known as small indigenous fishes (SIF). Among eight hundred and seventy seven local freshwater fish species of India, about four hundred fifty are cataloged as small indigenous fish and Northeast India is home to 216 species of them. The peaking diversity of these is recorded in Northeast Indian area followed by Western Ghat and Central India. They possess a lofty nutritional content of micro and macronutrients. Since they are easily available, hence is first hand choice for the poor and middle-class people to fill up the protein craving. The present piece of work reviews the occurrence of the small indigenous fishes and their function in defending malnutrition and more explicitly the deficiency caused due to micronutrients, which directly influences both standard of nutrition and economic security of the rural populace. It also reviews the threats to its diversity loss and improvement of conservation strategies. It attempts to create sensitization of food benefits of the SIF and create mass awareness to protect this bioresource for nutritional and livelihood security for the poor rural people of Northeast India. [ABSTRACT FROM AUTHOR]

Wetlands are considered as the heart of natural feeding and breeding grounds of many indigenous fishes of Bangladesh. These are also the most diversified habitat in the world. However, the wetlands of Bangladesh are in danger of extinction due to various manmade and natural causes. Therefore, wetlands need special attention to conserve this unique ecosystem of Bangladesh. As a part of the conservation measures needed for wetland ecosystem, the present study was undertaken to describe the abundance and diversity status of fish in Dingapota wetland of Bangladesh and to identify the key environmental factors influencing the fish community assemblage. A total of 52 fish species were recorded from 7 orders during the study period. Cypriniformes comprises the most abundant order (47.91%) followed by Perciformes (20.71%) and Clupeformes (20.22%). Higher number of species was recorded in post-monsoon season. Fish community assemblage was significantly differentiated among the three seasons (ANOSIM, Global R = 0.803, P < 0.05), while the overall average differences in the period of three seasons was estimated as 39.92% and similarity percentage analysis (SIMPER) revealed the greater contribution of Osteobrama cotio, Esomus danricus, Nandus nandus, Gudusia chapra and Chanda nama to ascertain this dissimilarity. Multivariate analysis based on non-metric multidimensional scaling (nMDS) generated three separate groups of each seasonal samplings and cluster analysis to find out natural grouping of samples according to their abundance. Diversity indices (Shannon-Weiner diversity (H), Margalef’s richness (D) and Pielou’s evenness (e)) were found to vary significantly among the seasons. Canonical correspondence analysis (CCA) revealed the significant roles of temperature, depth, transparency, pH, dissolved oxygen and alkalinity for structuring the community assemblage of fish in Dingapota wetland. Essential baseline information generated by this study will help the respective authority to formulate sustainable conservation measures for Dingapota wetland. [ABSTRACT FROM AUTHOR]

Simple Summary: The Nile tilapia (Oreochromis niloticus) (NT) is an aggressive and omnivorous species that competes with native fishes for food resources, and it has successfully invaded much of the Pearl River basin in China. Intensive research has focused on the gut microbiota of Nile tilapia in artificial culture. However, differences in gut microbes between invasive Nile tilapia and indigenous fish are relatively less well characterized. In the present study, we chose the black Amur bream (Megalobrama terminalis) as a native omnivorous fish that shared a common habitat and partially overlapped resource usage with Nile tilapia. Here, we investigated the gut microbiomes of invasive Nile tilapia and indigenous black Amur bream (BA) in the same river section using high-throughput 16S rRNA gene sequencing. The results indicated that the gut microbiome of NT had several special characteristics, e.g., higher alpha diversity and greater niche breadth, compared with the bream. Thus, the aim of the present study was to investigate the role of gut microbiomes between an indigenous fish (black Amur bream) and invasive Nile tilapia from the low region of the Pearl River basin to better understand the microbial complexity and diversity of their gut microbiota. The gut microbiome is thought to play vital roles in host fitness and local adaptation to new environments, thereby facilitating the invasion of the host species. The Nile tilapia (Oreochromis niloticus) (NT) is an aggressive and omnivorous species that competes with native fishes for food resources, and it has successfully invaded much of the Pearl River basin in China. Here, we investigated the gut microbiomes of invasive Nile tilapia and indigenous black Amur bream (BA) in the same river section using high-throughput 16S rRNA gene sequencing. The results indicated that the gut microbiome of NT had several special characteristics, e.g., higher alpha diversity and greater niche breadth, compared with the bream. The gut microbiota of the small size of Nile tilapia (NTS) and small size of black Amur bream (BAS) groups were dominated by Proteobacteria, while those of the NTS and large size of Nile tilapia (NTL) and BAS and large size of black Amur bream (BAL). BAL and NTL were characterized by Firmicutes and Fusobacteriota, respectively. We found that Pseudomonas, Cetobacterium, Ralstonia, and Romboutsia were biomarkers of the NTS, NTL, BAS, and BAL groups, respectively. Moreover, the results collectively suggested that the clustering coefficients of BAL and NTL networks were greater than those of BAS and NTS networks, and BAS had the smallest network among the four groups. Positive interactions between two ASVs dominated the BAS, NTS, and NTL networks, while the proportion of negative interactions between two ASVs in the BAL network was remarkably increased. Low levels of interspecies competition in the NT gut microbiome would contribute to high diversity in the dietary niches and would also benefit the survival and local adaptation of the host. Our results identified specific biomarkers of gut microbial species in invasive Nile tilapia and provided useful information concerning how to monitor and manage invasive Nile tilapia populations. [ABSTRACT FROM AUTHOR]

Age, growth and production performance of O. mossambicus (Peters, 1852) in relation to proliferation of population density in Jaisamand Lake, Udaipur (Rajasthan) has been described and analyzed in the present paper. In this study, the production data for fishing year 1995-96 (February 1995 to March 1996) and 2012-13 (February 2012 to March 2013) are compiled and simultaneously fish morphological data (length and weight) and scale samples are used for age and growth analysis. The findings show that contribution of Tilapia in the total fish production of Jaisamand hiked by 54% to 85% from 1995-96 to 2012-13 which conforms to the predicted invasive effect on other fish fauna and ecosystem of Jaisamand Lake. This increasing trend of Tilapia population is not only affected the indigenous fish population but age and growth structure of Tilapia also has been found affected. Age structure was composed of 3+ year classes during 1995-96. However, due to population density pressure dwarfism was noted and it increased to 4+ year classes. The growth in terms of length and weight also reduced and in AG 1+ 44.21% and 9.09%, in AG 2+ 62.86% and 24.64%, in AG 3+ 72.69% and 38.83% and in pooled population 72.70% and 47.66%, respectively exhibiting a clear decline. On the basis of these findings it can concluded that population increased density and consequent pressure adversely affected indigenous fish fauna resulting into reduced growth rate which directly or indirectly effects livelihood of fisherman and economics of state. [ABSTRACT FROM AUTHOR]

Zebra loach is one of the popular and desirable species in the ornamental sector that contributes to a major share for the world market of indigenous ornamental fish. Being categorized as Endangered under IUCN RedList, its identification has proved to be tricky owing to close variations in morphology and colour. The present study describes the application of morpho-taxonomy and genetic marker Cytochrome c Oxidase subunit I (COI) to understand the variations in Botia striata. COI gene (655 bp) was amplified using the universal primers and sequenced. A total of 10 samples were measured for standard length and the value ranged from 47.40 to 48.20 mm. Meristic characters i.e., fin rays of dorsal, pectoral, pelvic, anal and caudal fins; and lateral transverse scales on the body were measured. For all the samples, the percentage of Thymine was significantly higher compared to the other nucleotides i.e., 31.5%. The mean interspecific genetic distance among the species under study was found to be 0.037. The K2P based neighbor-joining (NJ) tree generated clustered the species according to their taxonomic position and showed that B. striata formed a separate clade (supported by 100% bootstrap value). The present study will be helpful in the identification of the Endangered and Vulnerable Botia species of Karnataka that will be beneficial for population studies, management and conservation programs. The present study also aids in developing a conservation-scheme approach for managing the fish diversity in their natural habitats. [ABSTRACT FROM AUTHOR]

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Copyright of Archaeology in Oceania is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Peoples can readily and affordably obtain small indigenous fish species (SIS), with a maximum length of 25 cm, that can be found in niches in small bodies of water (such as canals, ponds, wetlands, streams, etc.). SIS contribute valuable and significant macro- and micronutrients in Bangladesh. SIS are excellent suppliers of vitamins and minerals. The main micronutrients are copper, iodine, iron, selenium, chromium, and zinc, which can help prevent mineral deficiency and enzymatic response in the human body. SIS, such as the mola (Amblypharyngodon mola), cotio (Osteobrama cotio), darkina (Esomus danricus), etc., are easily digestible by the human gut. Nutrients of these fish are quickly accessible by the intestine. These fish are comparatively cheap and easy to capture and promote the presence of particular vitamins in SIS, including A, D, E, and K, as well as vitamin B components. This review paper focuses on the SIS nutritional contribution and their efficacy of preventing malnutrition in developing countries such as Bangladesh and the whole world. [ABSTRACT FROM AUTHOR]

Physical and chemical parameters of river influence the habitat of fish species in aquatic ecosystems. Fish showed a complex relationship with different aquatic factors in river. Machine learning modeling is a useful tool to identify relationships between components of a complex environmental system. We identified the preferred habitat indicators of Chanda nama (a small indigenous fish), in the Krishna River located in peninsular India, using machine learning modeling. Using data on Chanda nama fish distribution (presence/absence) and associated ten physical and chemical parameters of water at 22 sampling sites of the river collected during the year 2001–2002, machine learning models such as random forest, artificial neural network, support vector machine, and k-nearest neighbors were used for classification of Chanda nama distribution in the river. The machine learning model efficiency was evaluated using classification accuracy, Cohen's kappa coefficient, sensitivity, specificity, and receiver-operating-characteristics. Results showed that random forest is the best model with higher classification accuracy (82%), Cohen's kappa coefficient (0.55), sensitivity (0.57), specificity (0.76), and receiver-operating-characteristics (0.72) for prediction of the occurrence of Chanda nama in the Krishna River. Random forest model identified three preferred physicochemical habitat traits such as altitude, temperature, and depth for Chanda nama distribution in Krishna River. Our results will be helpful for researcher and policy maker to understand important physical and chemical variables for sustainable management of a small indigenous fish (Chanda nama) in a large tropical river. [ABSTRACT FROM AUTHOR]

In order to investigate the influence of the high-altitude aquatic environment on indigenous fish metabolites, metabolomics studies were applied in this study. Widespread throughout the main stem of the Nujiang River of Schizothorax nukiangensis, we established sampling sites at high (3890 m) and low (2100 m) altitudes and selected six S. nukiangensis at each location, each weighing approximately 150 g and looking healthy. Then, metabolomics analysis was performed to compare the various metabolites of the two groups. Low concentrations of amino acids, dipeptides, eicosapentaenoic acid, docosahexaenoic acid, pentadecanoic acid, Thioetheramide-PC, 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine, 1-Stearoyl-sn-glycerol-3-phosphocholine, 1-Myristoyl-sn-glycero-3-phosphocholine and 1-Palmitoyl-sn-glycero-3-phosphocholine, high concentrations in S-Methyl-5'-thioadenosine, creatine, D-mannose-6-phosphate, D-mannose-1-phosphate, oleic acid and myristoleic acid were found in high-altitude fish liver. These differentially accumulated metabolites were involved in oxidative stress, energy metabolism, carbohydrate metabolism and lipid metabolism. mTOR signaling pathway, apoptosis and lysosome were the KEGG pathways that were enriched between different groups to ensure energy supply and limit tissue damage of fish at high altitudes. All these results contributed to the understanding of the high-altitude adaptation of S. nukiangensis in the Nujiang River. Nicotine and methoprene, two organic pollutants, performed differently in fish at different altitudes. Overall, our findings advanced the fundamental understanding of fish responses to high-altitude environments, adaptive mechanisms and organic contaminants pollution in the Nujiang River. [ABSTRACT FROM AUTHOR]

Morphometric characteristics, length-weight relationships (LWRs), and condition factors (K) were studied for five indigenous fish species belonging to five different families (Barilius barila Hamilton, Cirrhinus reba Hamilton, Chanda nama Hamilton, Mystus bleekeri Day, and Clupisoma garua Hamilton), from the River Ganga in Bihar, India. A total of 557 fish individuals were collected seasonally from September 2021 to August 2022 using a monofilament drift gill net and a conical trap net Khairel jal. In morphometric analysis, the highest degree of correlation was observed between the total length and the standard length for all species (except C. garua). The estimated exponent value b varies from 2.920 to 3.214, where the slopes of regression lines among the species have significant differences (p < 0.0001). The b value indicated that three species (B. barila, C. nama, and C. garua) follow positive allometric growth, whereas M. bleekeri shows isometric growth and C. reba exhibits negative allometric growth. The condition factor value for these fishes ranged from 0.67 to 0.98, which indicated that the population of C. reba was robust compared to all other species (p < 0.0001). A new maximum length (146.8 mm) was obtained for B. barila from India. The present study gives baseline biological information on five commercially important indigenous fish species found in the River Ganga, Bihar. As the population of these species has been dwindling in recent times, these data will be important for the conservation and sustainable utilization of these important species in the long run. [ABSTRACT FROM AUTHOR]

Puntius chola (Hamilton, 1822) is a small freshwater indigenous fish with food and ornamental value belonging to the family Cyprinidae found in Pakistan, India, Nepal, Bangladesh, Myanmar, and Sri Lanka. Due to the selective exotic species and the culture of Indian big carp, the species have gradually diminished in India. Evaluating P. chola's optimum selection, induced breeding, embryonic, and larval development is the goal of the current study. The optimum dose was selected through the trial-and-error method applied 5 doses (0.25 ml/kg, 0.50 ml/kg, 1 ml/kg, 1.5 ml/kg, 2 ml/kg body weight) of synthetic hormone, ovatide to both sexes. The study reveals that the optimum dose of synthetic hormone ovatide @ 1.5 ml/kg body weight for females and males is effective for induced breeding of Puntius chola. At the optimum dose, fecundity, fertilization, and hatching rates were 106308±3075, 79.28±0.589%, and 78.03±0.495%, respectively. The physicochemical parameters of water have been enlisted for proper induced breeding. The outcomes of this research will enable P. chola to have a more decorative design and assist in its protection by encouraging it to reproduce and survive on its own in the wild. Additionally, the study will aid in community members' economic development. [ABSTRACT FROM AUTHOR]

Copyright of Advances in Water Science / Shuikexue Jinzhan is the property of Editorial Board of Advances in Water Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Agriculture / Poljoprivreda is the property of Josip Juraj Strossmayer University of Osijek, Faculty of Agriculture in Osijek and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In developing countries, poverty alleviation and development are key policy drivers, and ideally these strategies should align with climate change adaptation and resilience as well. This study explores those challenges through an inductive investigation into the East Kolkata Wetland (EKW), the ‘wise-use’ of wastewater, alignment with climate change adaptation, resilience and poverty alleviation. EKW is a 12,500 ha Ramsar site, close to Kolkata Metropolitan Area in eastern India and connected to Sunderban and the Bay of Bengal. While there are illegal demand-driven developments within EKW, the study explores how planning might provide for development while preserving the critical functions of a wetland. The study addresses three topics: (1) the socio-ecological model; (2) planning approaches to the wetland; and (3) how those might contribute to poverty alleviation. This study of EKW centers on the past and present ecological history of the city and includes analysis of future physical and institutional relations between the city and the wetland. The study benefits from participatory mapping exercises involving indigenous fishing and farming communities. [ABSTRACT FROM AUTHOR]

Simple Summary: The appearance of a species outside its native area due to human activities (e.g., canal openings, shipping, aquaculture) is described as a biological invasion, and these species are called non-indigenous. The Mediterranean Sea is prone to such an invasion, which is further enhanced by water temperature rising. Moreover, species from the Atlantic further expand their distribution in the Mediterranean, called neonative species, entering through the Gibraltar. Here, we examined the biological traits (e.g., preferred habitat and temperature, length, feeding habits) of fishes present in the Mediterranean Sea, as well as those from the neighboring Atlantic and Red Sea areas, and those that are neonative and non-indigenous in the Mediterranean. We applied state-of-the-art statistical analyses, aiming to describe their biological traits and spot those that could serve as predictors of species that could become neonative and non-indigenous for the Mediterranean. Overall, the results presented here could serve as a baseline for future research, and provide us with a useful tool to plan in advance measures for the protection of native Mediterranean fishes from such invasions. The Mediterranean Sea (MED) is prone to species' introductions, induced by human activities and/or climate change. Recent studies focus on the biological traits that result in such introductions, yet on a single-area-type approach. Here, we used, analyzed, and compared biological traits derived from FishBase for MED, non-indigenous (NIS) and neonative (NEO) in the Mediterranean, and adjacent Atlantic (ATL) and Red Sea (RS) species. A quantitative trait-based analysis was performed using random forest to determine the importance of traits in the successful establishment in the Mediterranean. MED fishes were mainly demersal, slow growing and small-medium sized, preferring intermediate temperatures. Conversely, ATL were mainly deep-dwelling species, preferring low temperatures. RS and NIS were predominantly reef-associated, thermophilus, and stenothermic. NEO species were stenothermic with preference to intermediate-high temperatures. Omnivores with preference to animals was the most common trophic group among regions. MED species exhibited higher phylogenetic uniqueness (PD50) compared to RS and NIS, indicating that they have long ancestral branches and few descendants. Preferred temperature, habitat type preference and maximum reported length (Lmax) and infinite length (Linf) were the most important predictors in the establishment process. Overall, the results presented here could serve as a baseline for future research, especially by using more refined and/or additional biological trail estimates. [ABSTRACT FROM AUTHOR]

This study determined the length-weight relationships of four fish species (Garra cambodgiensis (Tirant, 1883), Glyptothorax zanaensis Wu, He and Chu, 1981, Schistura nicholsi (Smith, 1933), and Schizothorax lissolabiatus Tsao, 1964) collected from the Lancang River (upper Mekong), China. The values of parameters a and b varied significantly. The a value and b value were 0.0087 and 3.3978 for G. cambodgiensis, 0.0125 and 3.0995 for G. zanaensis, 0.0265 and 2.7596 for S. nicholsi, and 0.0162 and 2.9736 for S. lissolabiatus, respectively. All the r2 values for the LWRs of the four fish species were over 0.95, indicating a reliable data fitting. The new maximum standard length (38.471 cm) was recorded for S. lissolabiatus. The reported findings are valuable for future population dynamic prediction and conservation of these fishes under rapid environmental degradation in the Lancang River. [ABSTRACT FROM AUTHOR]

Length–weight relationships of seven small indigenous fishes collected from the middle and lower stretch of the Tapti River in India were determined. The specimens were caught with drag nets (0 mm mesh size), gill nets (10–20 mm knot‐to‐knot mesh length) and scoop nets (0 mm) from the Maharashtra, and Gujarat state stretches of the Tapti River from November 2018 to December 2019. Digital calliper and digital balances were used to measure the total length (TL) and body weight (BW) of all fish specimens respectively. The growth coefficient b varied from 2.758 (Parambassis ranga) to 3.298 (Osteobrama cotio), and the LWRs were highly significant (p <.005). The present study established LWRs for the first time for seven fish species in the respective riverine habitat, including providing a new maximum length record for Corica soborna. The results of the present study will be useful for sustainable management and conservation of respective species in the river and its associated waterbodies. [ABSTRACT FROM AUTHOR]

Aquaculture produces about half the fish consumed globally and is the fastest‐growing food sector. In Africa, fish is one of the major sources of animal protein, and although the need for increased production of farmed fish to make up for the decline in capture fisheries is acknowledged, efforts put into aquaculture in the continent have not yielded commensurate results. The success recorded in aquaculture in Nigeria is based on the production of the African catfish. However, a high level of production and resilience within the aquaculture sector has been shown to be positively correlated with the culture of several species or species items. Thus, enhanced diversification of species and farming systems may boost aquaculture in Nigeria, as diversification of farming systems would allow optimum utilization of the abundant natural resources in the country. Many indigenous fish species that can be domesticated for culture have been identified. A great deal of scientific research and collaboration between major stakeholders, including the government, private industries, research institutions, and researchers, is required, so the production of these species can thrive like the already farmed catfish in Nigeria. As the successful domestication of any fish species takes a lot of time, effort, and resources, the species that have already proven to some extent to thrive in Nigeria, should be explored first. It is recommended that the best strategy for diversification of aquaculture for Nigeria is to increase the use of some already farmed species and the employment of a variety of production systems. [ABSTRACT FROM AUTHOR]

Aquaculture has great potential in the Terai region of Nepal due to the suitability of pond resources and government attempts to improve the fisheries sector. The majority of fish farmers in Chitwan belong to indigenous nationalities. Entrepreneurship skills help in uplifting local rural communities but due to the lack of attractiveness and economic production of fish in Chitwan, there is a higher chance of fish enterprise failure. Hence, an immediate need of assessing entrepreneurial behavior was felt and the study was carried out among indigenous fish farmers of Eastern Chitwan. For data collection, a questionnaire survey was conducted among eighty random respondents and a key informant interview was performed with expert farmers and fish scientists using the convergent parallel mixed method. Collected data were analyzed using SPSS version 22 and MS Excel. The entrepreneurial behavioral index (EBI) was calculated for each respondent, and it was assessed with various sociological and production factors. Average EBI was found among respondents. Most of the surveyed entrepreneurs have a low level of innovativeness, farming knowledge, and leadership while a medium level of motivation and decision-making ability. From the t-test, it was found that factors like AKC (Agriculture Knowledge Centre) visit, farming type, and organizational membership are significant but farmers' gender, extension consultation, training, information source, education, and experience are nonsignificant with respondents' entrepreneurship. Farmers who do commercial farming, visit AKC, and are members of social organizations have relatively more entrepreneurial behavioral indexes than other farmers. For the improvement of fish enterprises in the study area, training related to fisheries innovativeness, fish farming knowledge, and leadership is recommended through the collaboration of AKC and social organizations. [ABSTRACT FROM AUTHOR]

Indigenous Knowledge can be defined as expertise, skills, practices, ideas, experiences and information gained over a long period, sustained and passed on from generation to generation orally within a community in a particular geographic area, often forming part of its culture. The Sundarbans, the largest remaining tract of coastal mangrove wetlands in the world are surrounded by rivers, rivulets, and creeks pushing the islanders to pursue fishing as a source of subsistence. The present paper has sought to understand how the fishing community of the Sundarbans draws upon his repertoire of knowledge and beliefs to cope with the world in which it finds itself. This has required an understanding of not only the Sundarban's natural world, but its geomorphology, hydrology and also the social world--the people, economy, administration, and governance. Using the ethnographic method, this empirical study deals with the fishers' means and measures i.e. beliefs, cognitive elements, and techniques--while often preserving the traditional fabric, have evolved with time. This unique and effective indigenous knowledge needs to be conserved. Documentation of the existing valid indigenous knowledge with fishers' perception as well as scientific rationale will help in adoption and further improvement to fulfil the present need of the people. [ABSTRACT FROM AUTHOR]

The diversity of freshwater fish in the Indo-Nepal transboundary river is minimally known to the common people. The present study adopted an integrated approach to determine the genetic diversity of fish fauna from the river Gandak. We generated 59 DNA barcodes of 25 fish species, identified through meristic and morphometric characters. The studied species revealed monophyletic clustering in the BA topology with high posterior probability supports and sufficient genetic distances. The study hinted more rigorous sampling and development of DNA data are required to develop a robust barcode library for indigenous fishes of Gandak River. A similar attempt will be useful to detect the extant fish diversity of other transboundary riverine systems in India and abroad and assist in reassessing the checklist and encourage sustainable conservation direction to protect the faunal composition in a riverine ecosystem. [ABSTRACT FROM AUTHOR]

Simple Summary: Fish is an important source of nutritious fatty acids, which are necessary for the prevention of cardiovascular and neurological diseases. Many fish species are a major component of the human diet, especially for indigenous peoples from Siberia, Russia, but information about their fatty acid profiles is scarce. We studied the fatty acid content of four salmonid fish (Arctic cisco, least cisco, muksun, and Arctic charr) inhabiting water bodies of the Gydan Peninsula, Kara Sea basin. We found a high content of essential polyunsaturated fatty acids in local salmonid fishes. Arctic charr was the fish species with the highest concentration of fatty acids in the flesh. The results of our multivariate analysis may be useful for anglers, stakeholders, and local consumers. We assayed fatty acids in the flesh of Arctic cisco Coregonus autumnalis (adult and juvenile), least cisco Coregonus sardinella, muksun Coregonus muksun, and Arctic charr Salvelinus alpinus inhabiting water bodies of the Gydan Peninsula, Siberia, Russia. The highest concentrations of total and polyunsaturated fatty acids (PUFAs) were found in Arctic charr (27.8 and 9.5 mg g−1) and adult Arctic cisco (20.2 and 7.6 mg g−1), while the lowest concentrations occurred in juvenile Arctic cisco (7.5 and 3.6 mg g−1). Multivariate analyses divided all studied fish into five distinct groups with the highest similarity between least cisco and muksun and the highest dissimilarity between juvenile Arctic cisco and Arctic charr. Coregonid fish from the study area had a higher content of docosahexaenoic and eicosapentaenoic acids than their conspecifics from subarctic and temperate habitats. The flesh of the studied fish is a source of a healthy diet for humans. Taking into account that all the studied fish are components of the traditional diet of indigenous peoples in northwestern Siberia, our data may be useful not only for local consumers and anglers but also for stakeholders focused on food policy and food security in the area. [ABSTRACT FROM AUTHOR]

Much progress has been made in recent decades in achieving high-level recognition of indigenous fishing rights. Despite these advances, actualization of indigenous rights to own and control marine resources has proven challenging. Insufficient attention to the centrality of power and its workings in fisheries are often the subject of critiques and of calls for more empirical research. This paper draws on interviews, participant observation, cognitive mapping, scenario workshops, and policy document review to examine power configurations and dynamics in the tropical rock lobster (TRL) fishery in Torres Strait (TS), Australia. Despite recognition of indigenous commercial fishing rights by the High Court in 2013, there have been only limited changes in how fisheries governance operates in the region. The current TRL management plan also risks entrenching non-indigenous interests in the fishery, thereby preventing Islanders from achieving their aspiration to fully own and control TS fisheries. Through an analysis drawing from Foucault's theory of governmentality and Blaser's political ontology framework, we show (1) how current fisheries management structures, processes and discourses are at odds with Islanders' conceptions of the fisheries; and (2) how the existing regime excludes and renders silent Islander priorities. Our findings extend to indigenous-state relations in other state-managed fisheries. We believe our proposed conceptual framework can be useful in unveiling power relations that constrain indigenous rights and in identifying transformation options. We conclude that a sea change in conventional fisheries governance arrangements is needed to respond to new imperatives and expectations around indigenous fishing rights and interests. [ABSTRACT FROM AUTHOR]

Human alterations, such as hydropower development, are intensive and have negative impacts on fish and ecological environment. However, fish habitat restoration projects based on geographical morphology have not yet been reported in the Yangtze River. To explore engineering measures used to restore fish habitat structure and function, a mesoscale fish habitat restoration project was designed and constructed, which included restructuring of habitat topography in the fluctuating area. Three-dimensional computational fluid dynamics (CFD) models were used to simulate and predict the project's effect on the hydromorphology prior to construction, and an Acoustic Doppler current profiler (ADCP) was deployed to test and verify actual flow field improvement. Short-term effects on fish species sorting and their main ecological traits were examined. The results showed that vorticity and flow heterogeneity in the river reach increased, suggesting that the restoration projects created flow conditions favourable to indigenous fishes. Thus, pre-optimization using computer simulation is an essential and scientific procedure that could be used to increase the probability of river restoration success. The promotion of habitat diversity had strong effects on fish aggregation, especially for the rare and endemic fish species targeted. Fish abundance, catch biomass and species richness increased by 98.1%, 62.7% and 22.5%, respectively. There were significant differences (p < 0.05) in species number and catch abundance before and after the project. The number of rare and endemic fish species increased from four to nine species. Overall, this research provides evidence that the promotion of habitat hydraulic morphology heterogeneity accelerates the recovery of fish diversity and biomass. [ABSTRACT FROM AUTHOR]

For the first time, we revealed the life-history traits including growth pattern (length–weight relationships, LWRs), condition factors, form factor (a3.0), first sexual maturity (Lm), age at first sexual maturity (tm), life span (tmax), natural mortality (Mw), asymptotic length (L∞), and optimum catchable length (Lopt) of ten commercially important small indigenous fish species (SIFS) in the Oxbow lake (Baor), southwestern regions of Bangladesh. A total of 1651 specimens were sampled during January to December 2020 with traditional fishing gears including seine nets, gill nets, and lift nets. Individual total length (TL) and body weight (BW) were measured by digital slide calipers and digital balance, respectively. To calculate the Lm, empirical maximum length-based model was considered, and Lopt was calculated based on L∞. The TL vs. BW relationship indicated positive allometric growth for Chanda nama (Hamilton 1822), Channa punctata (Bloch 1793), Channa striata (Bloch 1793), Lepidocephalichthys guntea (Hamilton 1822), Macrognathus pancalus (Hamilton 1822), and Puntius sophore (Hamilton 1822), but negative allometric growth for Badis badis (Hamilton 1822), Gudusia chapra (Hamilton 1822), Glossogobius giuris (Hamilton 1822), and Hyporhamphus limbatus (Valenciennes, 1847). All r2 values exceed 0.910 that indicated all LWRs were highly significant (P < 0.001). According to Spearman correlation test, Fulton's condition factor (KF) vs. BW was highly correlated (P < 0.001), indicating better well-being for these species. Moreover, a3.0 indicates B. badis, C. punctata, C. striata, G. giuris, H. limbatus, L. guntea were elongated; C. nama, P. sophore, were short and deep; G. chapra was fusiform, and M. pancalus was eel-like body shape respectively. The minimum tm and tmax were obtained as 0.74 year and 2.66 year for C. striata and maximum were 0.93 year and 3.31 year for B. badis, respectively. This study provided information on tm and tmax for ten SIFS that is globally absent. From empirical models, the smallest mean value of Lm was found for B. badis (3.98 cm), and the greatest was found for C. striata (16.96 cm). The minimum Lopt was obtained as 3.78 cm TL for B. badis and maximum was 14.09 cm TL for C. punctata. The minimum Mw was documented as 1.39 for B. badis and maximum was 1.73 for C. striata. The output of this research will be helpful for developing sustainable management policies and protection of SIFS through the application of mesh size based on Lm and Lopt in the Oxbow lakes, Bangladesh and neighboring countries. [ABSTRACT FROM AUTHOR]

The current work represents the study on morphology and reproductive biology of two indigenous torrential fishes, Balitora brucei and Psilorhynchus balitora, for the first time. The Gray's stone loach Balitora brucei and balitora minnow Psilorhynchus balitora abound in the torrential water bodies of South East Asia. The current paper redescribes morphology based on the fresh collection. Specific parameters of reproductive biology on both the fishes have been studied for the first time. Both the species were adapted to the same ecological conditions of the river Ranganadi. Fish specimens were collected at a fortnightly interval from the river in the Lakhimpur district of Assam, India. The detailed study includes morphological data analyzed with Mann–Whitney U-test and specific reproductive parameters such as condition factor (K), gonado-somatic index (GSI), modified gonado-somatic index (MGSI), and Dobriyal index (DI). Progressive development of the gonads was confirmed with dissection and histological study. Both the species are multiple breeders with prolonged reproductive seasons ranging from 4 to 5 months. Both the fishes are found to be migrants from upstream, and a good number of individuals were recorded during the monsoon season, reflecting the sampling site as a breeding ground. During winter, the local people use various chemicals, piscicidal plants, and electric instruments for fishing resulting in a steep decline in the number of individuals for both the species. Moreover, the effect of the North Eastern Electric Power Corporation Limited (NEEPCO) dam is evident on the decline of the ichthyofaunal diversity of the river. The results of present study will provide the baseline information on these two species of fishes for planning conservation measures in future. [ABSTRACT FROM AUTHOR]

The Tamas River is a right-bank tributary of the River Ganga, originating from Jhukehi village in Madhya Pradesh and meeting up with the Ganga at Sirsa, Prayagraj, Uttar Pradesh, India. An investigation was carried out in six sites at (Itahara, S1), (Madhavgarh, S2), (Bakiya upstream, S3), (Bakiya downstream, S4), (Chakghat, S5) and (Panasaghat, S6) of the river to document the fish diversity, seasonal variability, and impact of environmental variables on fish species composition during the period 2017 to 2019. Altogether 75 fish species belonging to 54 genera, 23 families, and 10 orders were recorded. Fish species richness at (S1), (S2), (S3), (S4), (S5), and (S6) and was recorded as 9, 39, 38, 13, 61, and 49, respectively. Family Cyprinidae with 31 species contributing 41% was the most dominant family, followed by Bagridae (8%) and Schilbeidae (6.7%). Seasonal variation in fish species richness and diversity indices were observed in the river stretch. Maximum species richness (45) was observed at S5 during monsoon and a minimum (6) at S1 during post-monsoon. As per the International Union for Conservation of Nature categorization, 10 out of 75 fish species recorded from the river were considered to be threatened. Three exotic species, namely Cyprinus carpio, Oreochromis niloticus, and Hypophthalmichthys nobilis, were recorded at some stretches, which may be a concern for native fish diversity. Environmental variables like water temperature, pH, dissolved oxygen, water velocity, and alkalinity influenced the fish community structure. The selected (S1–S6) stretch of the river falls under the category of Slightly Impacted River based on the Shannon Index (H'>3). The present investigation was the first assessment of rich fish diversity covering the maximum stretch of river, which supports many important and small indigenous fishes for conservation. [ABSTRACT FROM AUTHOR]

Triplophysa tenuis is an important indigenous fish in the Xinjiang Tarim River. In this study, we collected 120 T. tenuis individuals from 8 T. tenuis populations in the Tarim River. Through genotyping-by-sequencing (GBS), a total of 582,678,756 clean reads were generated for all the genotypes, and after quality filtering, 595,379 SNPs were obtained for the population genetic analyses. Multiple genetic parameters showed that the 8 T. tenuis populations had high genetic diversity. Phylogenetic tree analysis indicated that all T. tenuis individuals were divided into five branches, the individuals from the north of Tarim River were grouped into cluster 1 (SF and WS) and cluster 3 (DWQ, TKX, and KZE), while the AETS, WLWT and LF individuals from the south of Tarim River were clustered into cluster 2. The result was consistent with the admixture analysis, which supported that the 8 T. tenuis populations were clustered into three subgroups. Furthermore, the pairwise F ST values and genetic distance indicated that there was a large genetic differentiation between WS and other T. tenuis populations. Collectively, this study provides valuable genome-wide data for the conservation of natural T. tenuis populations in the Tarim River. [ABSTRACT FROM AUTHOR]

The recent expansion of the round goby (Neogobius melanostomus) in tributaries of the lower Danube (Bulgaria) prompted assessing potential negative effects on local fish fauna such as competition for food resources. Diet overlap between the round goby and native fishes was analyzed using samples of fishes and macroinvertebrates collected monthly for a one-year period. Significant dietary overlap between N. melanostomus and Barbus petenyi, Perca fluviatilis, Gobio gobio, Vimba vimba, and Neogobius fluviatilis was observed. Dietary overlap in the Iskar River was found to be considerable mainly in the spring months. Conversely, overlap in the Vit River was observed during summer and late fall. The main reason for the overlap noted was the preference for Chironomidae and Hydropsychidae larvae and Gammaridae. The results suggest that there is potential for competition between the round goby and native fish species inhabiting the tributaries of the Danube. Potentially harmful effects on rare, protected fish species in the area are discussed. [ABSTRACT FROM AUTHOR]

Fisheries governance uses policy and statutory documents to improve governance on fish ecology, harvesting, trade and consumption by identifying and addressing gaps regarding inefficiencies, inequity and post‐harvest losses. The current study examines existing policies and institutional documents on fisheries, health and trade to assess the level of inclusion of small indigenous fish species (SIS), especially Omena, as a means of guiding governance interventions for sustained livelihoods of fishing communities in Lake Victoria. A content‐analysis review was conducted on all the fisheries and nutritional policy documents related to Lake Victoria fishery to ascertain the need for their integration into fisheries governance. From the scoring scale, where zero (0) implies no integration and three (3) implies high integration, the study results indicated very low levels of integration across health, fisheries and trade relating to small fish species. Further, the management plans and regulations/guidelines exhibited a relatively higher level of integration than did policies and laws. There is need for a more targeted approach for streamlining the existing policy documents to realize the untapped potential contribution of SIS towards food and nutritional security. [ABSTRACT FROM AUTHOR]