Aquatic Living Resources最新文献

{"title":"Genetic diversity and population structure of Tarek (Alburnus tarichi), an endemic species to the Lake Van basin, Turkey","authors":"Yılmaz Çiftci ,&nbsp;Oğuzhan Eroğlu ,&nbsp;Şirin Firidin ,&nbsp;Hacı Savaş ,&nbsp;Yusuf Bektaş ,&nbsp;Roman Wenne","doi":"10.1051/alr/2021005","DOIUrl":"10.1051/alr/2021005","url":null,"abstract":"<div><div>In this study, the genetic relationships of 804 tarek (<em>Alburnus tarichi</em>) samples from a total of 18 populations, including the potamodromus and resident individuals from Lake Van basin in eastern Turkey, were studied by using nine microsatellite loci. A total of 93 alleles was detected, and the average number of alleles per locus was 10.3 ± 3.39. The mean estimated observed and expected heterozygosity were 0.340 ± 0.016 and 0.362 ± 0.015, respectively, which indicated a low level of polymorphism. After Bonferroni correction (<em>P</em> &lt; 0.0027), the multi-locus test applied to each population revealed that 12 out of 18 populations were in Hardy-Weinberg equilibrium (HWE) (<em>P</em> = 0.0120–0.9981). Analysis of molecular variance (AMOVA) showed more than 76% genetic variability within individuals and 19% among populations, which was significantly higher than zero (F_ST = 0.19), and furthermore, a low level of genetic variation was observed among individuals within populations (4.84%: F_IS = 0.06). Bayesian clustering analysis indicated that the total genetic variation grouped into 3 clusters. Additionally, the significance test results revealed that 11 of the 18 populations are threatened with extinction due to recent bottleneck events.We conclude that the tarek populations from the Lake Van basin can be classified into distinct genetic groups, based on microsatellite information. In addition, our results provide essential information for the development of a management plan that conserves the tarek's genetic diversity and achieves a sustainable fishery.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can we identify wild-born salmon from parentage assignment data? A case study in the Garonne-Dordogne rivers salmon restoration programme in France","authors":"Marc Vandeputte ,&nbsp;Anastasia Bestin ,&nbsp;Louarn Fauchet ,&nbsp;Jean-Michel Allamellou ,&nbsp;Stéphane Bosc ,&nbsp;Olivier Menchi ,&nbsp;Pierrick Haffray ,&nbsp;Carlos Saavedra","doi":"10.1051/alr/2021008","DOIUrl":"10.1051/alr/2021008","url":null,"abstract":"<div><div>Parentage assignment with genomic markers provides an opportunity to monitor salmon restocking programs. Most of the time, it is used to study the fate of hatchery-born fish in those programs, as well as the genetic impacts of restocking. In such analyses, only fish that are assigned to their parents are considered. In the Garonne-Dordogne river basin in France, native salmon have disappeared, and supportive breeding is being used to try to reinstate a self-sustained population. It is therefore of primary importance to assess the numbers of wild-born returning salmon, which could appear as wrongly assigned or not assigned, depending on the power of the marker set and on the size of the mating plan. We used the genotypes at nine microsatellites of the 5800 hatchery broodstock which were used from 2008 to 2014, and of 884 upstream migrating fish collected from 2008 to 2016, to assess our ability to identify wild-born salmon. We simulated genotypes of hatchery fish and wild-born fish and assessed how they were identified by the parentage assignment software Accurassign. We showed that 98.7% of the fish assigned within the recorded mating plan could be considered hatchery fish, while 93.3% of the fish in other assignment categories (assigned out of the mating plan, assigned to several parent pairs, not assigned) could be considered wild-born. Using a Bayesian approach, we showed that 31.3% of the 457 upstream migrating fish sampled from 2014 to 2016 were wild-born. This approach is thus efficient to identify wild-born fish in a restoration program. It remains dependent on the quality of the recording of the mating plan, which we showed was rather good (&lt;5% mistakes) in this program. To limit this potential dependence, an increase in the number of markers genotyped (17 instead of 9) is now being implemented.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The relationship between target strength frequency response and vertical swim velocity: a new approach for fish discrimination","authors":"Hikaru Homma ,&nbsp;Ilia Ostrovsky ,&nbsp;Verena Trenkel","doi":"10.1051/alr/2021011","DOIUrl":"10.1051/alr/2021011","url":null,"abstract":"<div><div><em>In-situ</em> identification of fish species using acoustic methods is a key issue for fisheries research and ecological applications. We propose a novel approach to fish discrimination based on the relationship between target strength frequency response (TS(<em>f</em>)) and vertical swim velocity (VSV), as a proxy of fish body orientation. The measurements were carried out with a wideband echosounder on live fish of five species confined in a net cage. The data show a large dependence of TS(<em>f</em>) on VSV. To compare the variability of frequency responses of different fishes, we calculated ΔTS(<em>f</em>, VSV) as the difference between the TS(<em>f</em>) at given VSV and the TS(<em>f</em>) at VSV = 0, i.e. when the fish was swimming horizontally. We demonstrated that the relationships between ΔTS and VSV were similar for fish of the same species but dissimilar for different species. This implies that the acoustic fish discrimination in nature might be performed when the variations of the VSV can be measured from acoustically tracked fish. This can be a promising method for remote fish discrimination, for instance, for fish with diurnal vertical migrations. Further validation of this approach for fish recognition is required.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping and estimating harvest potential of seaweed culture using Worldview-2 Satellite images: a case study in Nusa Lembongan, Bali − Indonesia","authors":"Indra Pratama ,&nbsp;Hatim Albasri ,&nbsp;Ellen Kenchington","doi":"10.1051/alr/2021015","DOIUrl":"10.1051/alr/2021015","url":null,"abstract":"<div><div>Unreliable information on harvest potential is a persistent challenge for the Indonesian government and industry alike to manage an efficient supply chain of seaweed raw material. The use of remote sensing technology to assess seaweed harvest potential has been scarcely available in the literature. This current research aimed at estimating the harvest potential of seaweed <em>Kappaphycus alvarezii</em> through remote sensing using supervised classification with maximum likelihood (MLC) and contextual editing (CE) methods. This research evaluated the capabilities of different band combinations along with depth invariant index (DII) to enhance the remote sensing accuracy in estimating seaweed harvest potential. The seaweed classification using Worldview-2 imagery was compared with the in-situ references (ground-truthing). The potential data bias resulted from different imagery acquisition timestamps with the in-situ measurement was kept minimal as both data time stamps were ten days apart and within the same seaweed culture cycle. The average dry weight of all seaweed samples collected during the research was 924 ± 278.91 g/m² with culture ages between 1 and 40 days. The classification results based on MLC+CE with a 5-band combination method without DII showed a better correlation and closer fit with the in-situ references compared to the other methods, with an overall accuracy of 79.05% and Tau coefficient value of 0.75. The estimated total harvest potential based on the combined seaweed classes was 531.26 ± 250.29 tons dry weight.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Socio-economic portrait of Polish anglers: implications for recreational fisheries management in freshwater bodies","authors":"Tomasz K. Czarkowski ,&nbsp;Arkadiusz Wołos ,&nbsp;Andrzej Kapusta ,&nbsp;Ralf Doering","doi":"10.1051/alr/2021018","DOIUrl":"10.1051/alr/2021018","url":null,"abstract":"<div><div>Recreational fisheries are an important element of contemporary fisheries. Detailed information about the motivation and opinions of anglers regarding catch-and-release fishing in post-communist countries, such as Poland, has not been widely available to date. The aim of this study was to fill this gap. We obtained 936 survey questionnaires completed by anglers from throughout Poland. The mean annual catch of a Polish angler is 126 fish weighing 46.1 kg. Anglers catch mainly cyprinids, but they would prefer to catch large predatory fishes, and they spend an average of 416.50 EUR on this activity annually. These results confirm the hypothesis that angling catches in Poland are decidedly of a recreational character and that catches targeted at fish consumption are of lesser importance. Simultaneously, we determined that younger anglers are more willing to release caught fish than older anglers.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Observations on feeding habits of the common dolphinfish, Coryphaena hippurus (Linnaeus 1758) from the western Bay of Bengal","authors":"Shubhadeep Ghosh ,&nbsp;Satishkumar Mamidi ,&nbsp;Manas Hoshalli Munivenkatappa ,&nbsp;Prathibha Rohit ,&nbsp;Abdussamad Eruppakkottil Median ,&nbsp;Gopalakrishnan Achamveetil ,&nbsp;Flavia Lucena Fredou","doi":"10.1051/alr/2021022","DOIUrl":"10.1051/alr/2021022","url":null,"abstract":"<div><div><em>Coryphaena hippurus</em> is a large pelagic species and constitutes an important by-catch in drift gillnet, trolling and long-line fishing gears operated along the Bay of Bengal, northeastern Indian Ocean. The present study, first from the region, is aimed at deciphering the feeding dynamics from 1150 individuals collected from 2017 to 2019. 32.17% of the fishes had empty stomachs or was with food traces, 45.57% had partially-full stomachs and 22.26% had full stomachs. The feeding intensity was inferred through stomach filling and predator-prey weight ratio, which was higher in May and lower in January, and increasing as increase in the fish size. <em>Coryphaena hippurus</em> is considered a piscivorous pelagic predator as pelagic teleosts contribute more than half of the prey species. Major prey species were big-eye scad (27.3%), squid (10.3%), crabs (9.3%), Indian mackerel (7.2%), Indian scad (5.9%), whitebaits (5.7%) and sardines (5.4%). Scads and crabs were abundantly preyed during summer and winter, while clupeids and engraulids in monsoon; however, no significant variations were observed in prey composition between sizes. Trophic Level was 4.22 ± 0.15 and Levins Standardized Niche Breadth Index was 0.30. Dietary niche breadth was higher during summer (0.48) and monsoon (0.33) and in fishes measuring 60.0–74.9 cm (0.51) and below 45.0 cm (0.48) indicating generalised feeding. This primary study from Bay of Bengal is the first comprehensive report on trophodynamics for the species and would contribute to its management using trophic interactions.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synbiotic containing Kappaphycus alvarezii, Spirulina sp. and Halomonas alkaliphila improves survival, growth and vibriosis resistance in whiteleg shrimp (Litopenaeus vannamei) post-larval culture","authors":"Magdalena Lenny Situmorang ,&nbsp;Puri Nurwidayanti ,&nbsp;Gede Suantika ,&nbsp;Domenico Caruso","doi":"10.1051/alr/2021009","DOIUrl":"10.1051/alr/2021009","url":null,"abstract":"<div><div>The high losses in shrimp production due to mortality caused by <em>Vibrio</em> opportunistic pathogens still constitute a significant challenge in the shrimp industry. Synbiotic feed supplementation appears to be a promising control strategy to maintain healthy shrimp stock. In this study, the effects of synbiotic-containing prebiotic seaweeds <em>Kappaphycus alvarezii</em> and <em>Spirulina</em> sp. as well as probiotic <em>Halomonas alkaliphila</em> were evaluated on the survival, growth, and vibriosis of <em>Litopenaeus vannamei</em> during the post-larval stage. Five different feeds were tested: commercial feed, prebiotics <em>K. alvarezii</em> and <em>Spirulina</em> sp.-supplemented feed, and synbiotic-supplemented feed using <em>K. alvarezii, Spirulina</em> sp. and probiotic <em>H. alkaliphila</em> with different concentrations of 10⁸, 10⁹, and 10¹⁰ CFU.kg⁻¹. Following 14 days after the feeding test, the highest shrimp survival (91.46 ± 0.05%) was obtained in the treatment group fed with synbiotic-supplemented feed containing 0.375% <em>K. alvarezii</em>, 0.125% <em>Spirulina</em> sp., and <em>H. alkaliphila</em> at 10⁹ CFU.kg⁻¹ (<em>p</em> &lt; 0.05). A 7-day challenge test against opportunistic bacteria <em>Vibrio harveyii</em> was then performed using three treatment groups: (1) synbiotic, containing 0.375% <em>K. alvarezii</em>, 0.125% <em>Spirulina</em> sp., and <em>H. alkaliphila</em> at 10⁹ CFU.kg⁻¹; (2) prebiotic, with 0.375% <em>K. alvarezii</em>, 0.125% <em>Spirulina</em> sp.; and (3) control, using commercial feed. The highest shrimp survival of (79.9 ± 0.05%) was found in the synbiotic treatment group, followed by the prebiotic and control treatment groups (<em>p</em> &lt; 0.05). Overall results suggested that synbiotic-supplemented feed containing 0.375% <em>K. alvarezii</em>, 0.125% <em>Spirulina</em> sp., and <em>H. alkaliphila</em> at 10⁹ CFU.kg⁻¹ significantly improved shrimp survival even when challenged with <em>V. harveyii</em>. Thus, this synbiotic can be potentially applied as an alternative biocontrol strategy against vibriosis in intensive shrimp post-larval culture.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of a lagoon on performances of a freshwater fishpond in a multi-trophic aquaculture system","authors":"Christophe Jaeger ,&nbsp;Marc Roucaute ,&nbsp;Sarah Nahon ,&nbsp;Jacques Slembrouck","doi":"10.1051/alr/2021004","DOIUrl":"10.1051/alr/2021004","url":null,"abstract":"<div><div>Integrated multi-trophic aquaculture (IMTA) is a way to help preserve the environment while maintaining a good level of total production. An ecologically semi-intensive pond system was designed in which a polyculture fishpond was associated with a lagoon planted with macrophytes to bioremediate the water. The properties of this “semi-intensive coupled” system (SIC) were compared to those of semi-intensive (SI) and extensive (E) systems, each of which was contained in a single fishpond with the same fish polyculture (common carp (Cyprinus carpio), roach (Rutilus rutilus), and perch (Perca fluviatilis)) as SIC. E differed in that it had half the initial density of fish, and the fish were not fed. Fish growth performances, water quality (chemical and biological indicators), chlorophyll concentrations, and invertebrate production were measured. The systems were compared based on fish production performances and physicochemical and biological characteristics, and were then described using principal component analysis (PCA). Carp and roach in the two fed systems had higher growth performances than those in E. Compared to SI, the planted lagoon in SIC, induced a decrease of 15% in fish growth performances and of 83% in total chlorophyll concentration (a proxy for phytoplankton) but improved water quality (−34%, −60% and −80%, for the concentrations of total nitrogen, total phosphorus, and blue green algae (for micro-algae in class Cyanophyceae), respectively). According to the PCA, SIC clearly differed from SI in benthic macro-invertebrate production and concentrations of total nitrogen, total phosphorus, and brown algae (for micro-algae in class Dinophyceae or a branch of Bacillariophyta) in the water. SIC differed from E in oxygen parameters (dissolved and saturation), estimated annual zooplankton production, and pH. In conclusion, the properties of a lagoon reveal perspectives for environmentally friendly practices, while using biodiversity and secondary production in order to enhance fish production.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Towards transdisciplinary decision-support processes in fisheries: experiences and recommendations from a multidisciplinary collective of researchers","authors":"Claire Macher ,&nbsp;Nathalie A. Steins ,&nbsp;Marta Ballesteros ,&nbsp;Marloes Kraan ,&nbsp;Katia Frangoudes ,&nbsp;Denis Bailly ,&nbsp;Michel Bertignac ,&nbsp;Francesco Colloca ,&nbsp;Mike Fitzpatrick ,&nbsp;Dorleta Garcia ,&nbsp;Rich Little ,&nbsp;Simon Mardle ,&nbsp;Arantza Murillas ,&nbsp;Lionel Pawlowski ,&nbsp;Manuelle Philippe ,&nbsp;Raul Prellezo ,&nbsp;Evelina Sabatella ,&nbsp;Olivier Thébaud ,&nbsp;Clara Ulrich ,&nbsp;Dorothy Dankel","doi":"10.1051/alr/2021010","DOIUrl":"10.1051/alr/2021010","url":null,"abstract":"<div><div>The shifting policy focus towards Ecosystem Based Management in Fisheries (EBFM) requires the integration of knowledge and disciplines and the engagement of stakeholders to support decision-making processes. Scientists contribute to this through (i) participatory research projects, (ii) stakeholder partnerships and (iii) institutional scientific advice processes. Understanding the role of scientists in such processes, the nature of the interactions between scientists, stakeholders and managers in knowledge integration and the link between science and policy is an emerging field of research addressing transdisciplinary challenges. In 2018, Ifremer-UMR AMURE organized the workshop ‘Science, Partnership and Decision-support in Fisheries’ bringing together international scientists from natural and social sciences to conduct a review based on twenty concrete case studies. Findings indicate that science-stakeholder-manager partnerships for decision-support in fisheries can play an essential role in the transition to EBFM. To foster this transition, eight recommendations are presented that cover the roles of the different participants, the expectations of partnerships, capacity building, the integration of the social sciences, and funding structures. Further, it is recommended that future research and innovation framework programmes into sustainable fisheries and other ocean uses should explicitly include mechanisms to foster transdisciplinary approaches and the development of best practices. Building-up networks and developing reflexive approaches to review experiences and practices for transdisciplinary approaches in EFBM decision-support will contribute to design the next generation transdisciplinary platforms and generating actionable knowledge towards EBFM.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supplementation of biofloc in carp (Cyprinus carpio var. Communis) culture as a potential tool of resource management in aquaculture","authors":"Shib Kinkar Das ,&nbsp;Amit Mandal ,&nbsp;Joel Aubin","doi":"10.1051/alr/2021019","DOIUrl":"10.1051/alr/2021019","url":null,"abstract":"<div><div>Supplementation of biofloc in rearing of common carp (<em>Cyprinus carpio</em> var. <em>Communis</em> (0.84 ± 0.003 g) was tested in replacing costly feed and environmental amelioration. Neem (<em>Azadirachta indica</em>) leave extract in biofloc media has beenknown to be beneficial in controlling pathogenic <em>Vibrio</em> sp. in brackish water shrimp. Two studies were conducted for 120 days in outdoor experimental cisterns with reduction of feed from 50% to 100%, with two biofloc media; without (Experiment 1; E1) and with neem extract (Experiment 2; E2). The experimental groups were: biofloc with feeding at 6% body weight (T1E1 and T1E2), biofloc with feeding at 3% body weight (T2E1 and T2E2), biofloc without feeding (T3E1 and T3E2), feeding at 6% body weight (C1) and only biofloc (C2E1 and C2E2). Absolute weight gain in T2E1 (9.96 g) was 8.23% and in T2E2 (9.56 g) was 4.39% higher than C1 (9.14). In spite of 5.04% and 13.98% higher growth respectively in T1E1 (10.50 g) and T1E2 (11.66 g) than C1 (9.97 g), BFT could not compensate the total withdrawal of feed (T3E1 and T3E2) and resulted in 22.22% to 33.33% mortality in T3E2 and T3E1 respectively. Under identical feeding regime, FCR was improved by 52.57% to 53.76% in T2E1 (1.84) and 48.71% to 51.23% in T2E2 (1.99) compared to T1E1 (3.98) and T1E2 (4.08). Absolute weight gain in T2E1 was 8.97 times and in T2E2 was 4.63 times higher than C1. In spite of 18.54% and 7.26% higher growth respectively in T1E1 and T1E2 than C1, BFT could not compensate the total withdrawal of feed (T3E1 and T3E2) and resulted in 22.22% to 33.33% mortality in T3E2 and T3E1 respectively. Under identical feeding regime, FCR was improved by 52.57% to 53.76% in T2E1 and 48.71% to 51.23% in T2E2 compared to T1E1 and T1E2 respectively. Increased N: P ratio of water and soil in E2 favoured fish growth. Neem leave extract in biofloc media should be judicious as it may cause nitrification inhibition.</div></div>","PeriodicalId":55491,"journal":{"name":"Aquatic Living Resources","volume":"34 ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2021-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57824734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}