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BACKGROUND AND OBJECTIVE Sessiline ciliates live as eco commensals (low numbers) and parasites (high numbers) on different hosts, like mollusks copepods, mysids and fish. Riboscyphidia ecto-protozoan is moderately pathogenic but high numbers of it on the gills can physically prevent gas exchange. The present study aimed to describe the epizoic ciliates Riboscyphidia found on the Red Sea cultured Asian sea bass and obtain more information on the Epidemiology of the parasite with special references to control and histopathological examination of naturally infected sea bass. MATERIALS AND METHODS The occurrence of epizoic ciliates on the adult Asian Sea bass. About 100 Asian sea bass were collected by the fishing net at a private marine fish farm at Ismailia governorate and transferred to the hydrobiology laboratory at National Research Centre. A parasitological and histopathological study of epizoic sessile ciliate species was done. ANOVA test was used for Statistical analysis. RESULTS Riboscyphidia sp. was found and isolated after parasitological examination of investigated adult's Asian sea bass. The prevalence of Riboscyphidiosis was 64%. Sessile ciliates were found on gills, skin and fins. The clinical signs of Riboscyphidiosis were respiratory distress, flashing and off food. Histopathological alterations in naturally infested Asian sea bass were investigated. CONCLUSION The treatment of choice of Riboscyphidiosis was prolonged immersion by Copper citrate with a dose of 0.56 mg mL-1 for 7 days.

Recreational fishing in Australia makes important contributions to local economies and fisheries harvests. Historical evaluations of the cumulative effects of exploitation for most recreationally targeted Australian fish stocks remain unexplored, as do the social and cultural contexts of recreational fishing. Historical newspaper articles were used to derive quantitative and qualitative catch data on Queensland's east coast barramundi, Lates calcarifer (Bloch), a popular species targeted by recreational fishers. Decadal-scale catch rates (1869–1952) were reconstructed, as was the development of the fishery since its earliest documentation. Models indicated a significant decline in catch rates, from an average of 5.20 kg /fishing trip (95% confidence interval, 3.82–7.09) in 1870–3.24 kg/fishing trip (95% CI 2.72–3.87) in 1952. Variability in catch rates was associated with a spatial and seasonal interaction effect, with average catch rates differing among regions and seasons. Qualitative analysis showed a northward expansion of the fishery along the east coast, coinciding with increasing number of locations fished, establishment of organised fishing clubs in the 1900s and concerns of overexploitation starting in 1909. Integration of quantitative and qualitative analysis revealed past socio-cultural factors and trends in the barramundi fishery, while building confidence in the reliability of inferences made from archival data sets.

The use of fish waste as raw material in producing gelatin becomes important when it is related to the halal perspective. Sea bass skin contains high protein, especially collagen protein which can be used as the main component of edible film. An edible film made from gelatin of fish skin usually lacks water vapour transmission due to its hydrophilic properties. Modification of formula in producing an edible film from fish gelatin with the addition of lipid such palmitic acid (PA treatment) and soybean protein isolate (SPI treatment) can affect the characteristics of the edible film resulted. This study was aimed to evaluate the chemical (solubility, water vapour permeability) and physical characteristics (thickness, tensile strength, per cent elongation, SEM) of an edible film made from gelatin with the addition of palmitic acid and soybean protein isolate with different concentration. The results showed that edible films with SPI addition yield the best film thickness (3.92 MPa) according to the Japanese Industrial Standard. The per cent elongation of both films with PA (21.3-34.44%) and SPI (36.06-117.53%) addition decreased with increasing concentration, but SPI generally gave higher elongation compared to PA. The addition of SPI gave lower solubility and higher water vapour transmission values compared to PA, however, the addition of 4.5% of PA gave the lowest water vapour transmission (5.416 g/m2 h). Therefore, the best treatment in this study was concluded to be 4% of SPI addition based on the best thickness, per cent elongation, water vapour transmission and solubility results.

The study is aimed to extract and characterize collagens from the skin and scale of two selected Nigerian freshwater fish species (Heterotis niloticus and Lates niloticus) using either pepsin (PSC) or acid-soluble (ASC) extraction. The collagen was extracted using 0.5M acetic acid and pepsin. The collagen yield was determined and characterized by SDS PAGE, and FTIR. Collagen extraction yields varied with the extraction process; the yield was significantly higher in the skin (5.08±0.34–33.97±1.78 %) than in the scale (1.76–8.05 %). The absorption peaks of the extracted collagen using acetic acid and pepsin show that only ASC of skin (3344.27 cm-1) and scale (3495.85 cm-1) of H. niloticus shows the peaks characteristic of Amide A, while Amide B peaks of collagen extracted from the skin and scale of H. niloticus and L. niloticus were found at 2974.46 cm-1 and 2925.7 cm-1 , representing an asymmetrical stretch of CH2. Similarly, ASC on the skin (1558.36 cm-1) and scale (1576.46 cm-1) of H. niloticus shows the absorption peak characteristics of amide II. ASC on the skin of H. niloticus (1671.05 cm-1), PSC on scale of H. niloticus (1658.55 cm-1), and on scale of H. niloticus (1678.65 cm1) shows absorption peaks in range characteristic of amide 1. There were no differences in the skin and scale collagen profiles among the two fish species when characterized by SDS-PAGE. Our data revealed that the skin and scale of Lates niloticus and Heterotis niloticus could be a good alternative source of high-quality collagen for industries.

Impact of bio-calcium from bone (FBC) of Asian sea bass (Lates calcarifer) at 8% (w/w) without and with calcium chloride (CC) or calcium lactate (CL) at different levels (0.1–0.6%, w/w) on gel char...

Freshwater is a critical input to estuaries but is under increasing demand to support upstream human activities. In this study, otolith biochronology was used to quantify the relationship between river discharge and juvenile growth rates of barramundi (Lates calcarifer) in three regions of the Gulf of Carpentaria in northern Australia. In all regions, river discharge had a strong positive effect on juvenile growth rates. Models were also developed which incorporated the Southern Oscillation Index (SOI) and the Madden–Julian Oscillation (MJO). SOI values corresponding to La Nina events had strong positive consequences for juvenile barramundi growth rates in all regions, and the intensity of positive wet season MJO pulses had a strong positive effect on growth rates in the perennially flowing river, but not the intermittently flowing rivers. The consequences of three hypothetical water development scenarios were estimated for the perennial river. The model predicted a 12%, 8% and 1% reduction in annual barramundi growth rates under proposed scenarios for 18%, 8%, and 3% reduction in river discharge, respectively. Fish growth is a robust, quantitative metric that can be monitored pre and post water resource development to identify the least impactful development scenario and monitor its compliance and success through time.

Postharvest processing and preservation of fish have great influence on fish quality and consumption. Freshwater fish in Sudan are facing problems related to bad handling and improper storage which reduce their quality. This study investigated the changes in the chemical composition, mineral contents, pH and acid value during storage (−18°C) of five commercial fish species (Bagras bayad, Lates niloticus L., Mormyrus casahive L., Oreochromis nilotica L., and Synodrontis schall) from the River Nile coast of Sudan. The fish species are rich in protein (17.22%–23.60%) but have low fat and ash contents. Frozen storage of the fishes for 45 days reduces their protein contents while the fat and ash contents were increased (p ≤ .05). Potassium and iron are the predominant major and trace minerals and their values were increased with storage period. The pH range from 5.74 (O. niloticus) to 6.24 (B. bayad) while acid value range from 0.02 (M. casahive) to 0.12 (L. niloticus). Both pH and acid values increased with storage period. In conclusion, storage of these fish species for up to 45 days did not adversely affect their nutritional value., Freshwater fish in Sudan are facing problems related to bad handling and improper storage which reduce their quality. This study investigated the changes in the chemical composition, mineral contents, pH, and acid value during storage (−18°C) of five commercial fish species from the River Nile coast of Sudan. Storage of these fish species for up to 45 days did not adversely affect their nutritional value.

This investigation describes the impacts of dietary provisioning with astaxanthin on hemato-biochemistry, non-specific immunity, and disease resistance of the Asian seabass, Lates calcarifer, against the virulent Vibrio alginolyticus; with specific reference to dose-response associations and variations over different post-infection periods (0-, 7-, and 14-day). Triplicate groups of fish weighing 28 g, on average, were fed various diets (C, the control or astaxanthin-free; AXT50, 50 mg astaxanthin kg−1 diet; AXT100, 100 mg astaxanthin kg−1 diet; and AXT150, 150 mg astaxanthin kg−1 diet) for 90 days and subsequently challenged with V. alginolyticus at the end of the feeding period. Experimental infection unveiled that supplemented fish demonstrated significant improvements (P

Though Asian Seabass, which is locally known as "Koral"/"Vetki," is a vital species in terms of its popularity and price, little is known about the location of breeding and nursery ground, peak breeding season, peak harvesting season, population dynamics, harvesting operation (gears and crafts used for harvesting) of this species in Bangladesh. An investigation was carried out to enlist the group of crafts and gears that are being operated on the Bay of Bengal coast by the fishermen for Asian seabass harvesting. The survey was based on interviews with the local fishermen and secondary data collected from the regional fisheries offices. The study revealed a total of 10 distinguishing fishing gears, including seven nets and two types of hook and lines were used for harvesting this fish. Some are selective for harvesting Seabass, but most of them are involved in multi-species exploitation. Four types of motorized and two types of non-motorized traditional boats are being used for harvesting the seabass in Bangladesh. The seabass fishery extends almost throughout the year at different life stages. The Koral net, Mela Barshi (Single Hook and line), and Push net were found to be effective for catching adult, pre-adult, and juvenile Asian seabasses, respectively. The Sampan boat and Mela barshi were reported for the first time as fishing boats and fishing gear in Bangladesh.

Cloud, grid, parallel, volunteer, and opportunistic computing are different forms of distributed computing and each of these concepts addresses different problems in data analysis. One of the latest virtualization technologies, containerization, provides new capabilities with a thin layer on end-user desktop computers in the field of distributed computing. From the viewpoint of management information systems, the information is the key element in decisionmaking processes, and in the age of the Internet the information that is necessary for organizations is accessible from publicly available open sources. Every organization needs to operate an open-source intelligence process to use the open-source data in different levels of management. However, the problem is that each organization needs data scientists and hardware and software resources to fulfill this requirement. Big enterprise companies or governments can make an investment to solve this problem, but small and medium-sized enterprises or small institutions may not have enough budget. A distributed microservice-based data analysis model with the technology of Docker containerization on the end-user computers is proposed.

Barramundi (Lates calcarifer) is one of the commercial fish in Indonesia. The phenomenon of climate change due to global warming has affected the life of aquatic biota, including fish. The objectives of the present study were to determine a critical thermal maximum (CTMax) and the behavior of Barramundi (L. calcarifer) due to the increase in water temperature. The research was conducted at the Fishing Technology Laboratory, Faculty of Marine and Fisheries, Universitas Syiah Kuala in February 2021. The experiment was conducted in 10 aquariums equipped with heaters. The initial temperature of the treatment was 28 o C and increased gradually every one minute by 0.2 o C. The results showed that the abnormal behavior of Barramundi fingerling was started to appear at 37 o C where the fish began to swim fast, then swim sideways at 38 o C-39 o C, hit the container wall at 39 o C-40 o C, jumped and weakened then dead at 40 o C and 41 o C. The average critical temperature of Barramundi fingerling was recorded at a temperature of 41 o C within 65 minutes. Therefore, it is concluded that the Barramundi (L. calcarifer) display an abnormal behavior above the temperature of 35 o C, however, they can survive up to 42 o C exposure for 70 minutes. Keywords: Critical thermal maximum Temperature rise Global warming

Fish bone by-products are considered as abundant source of hydroxyapatite (HAp). The preparation of HAp from fish bones not only contributes to improving the value of by-products but also minimizes negative impacts on the environment. In this study, nanohydroxyapatite was successfully obtained from Lates calcarifer fish bone purchased from seafood export company in Khanh Hoa province. Fish bones were under alkali treatment and then heated at 600oC within different time intervals of 1, 2 and 4 hours. Analysis of XRD and SEM showed that the calcium formed was completely single-phase and possessed an average size of 50–64 nm depending on the calcination time. The results of the Ca/P molar ratio from 1.839 to 1.847 prove that the nano-HAp powders are B-type biological hydroxyapatites, which has been confirmed by FTIR spectrum. In addition, the content of heavy metals such as As, Pb, Hg, Cd is detected within safety limits. These properties allow nano-HAp powders to be applied in food and medicine fields.

The age of whole otoliths from barramundi (Lates calcarifer) obtained from the southern Gulf of Carpentaria were estimated using Fourier transform near-infrared (FT-NIR) spectroscopy. Otoliths from 1716 barramundi collected in 2006, 2009 and 2012–2015 were used in this study. Partial least-squares regression models (PLS-R) and multiple linear regression models (MLR) were developed from the diffuse reflectance spectra and the age was obtained from traditional sectioned otoliths. Calibration models were built up over consecutive years (2012–2015) by using a subset of the samples and used to predict the age of the remaining samples and samples from the following year. Results suggest that when seasonal (temporal) variability is incorporated into the calibration model, FT-NIR has the ability to predict barramundi age (validation R2 ranged from 0.73 to 0.78; RMSEP ranged from 6.92 to 7.64 months). The predicted age class was within 1 year of the reference age in over 96% of the samples. These models were also able to predict the age of otoliths from 2006 and 2009, which were retrieved from long-term storage (validation R2 ranged from 0.77 to 0.84; RMSEP ranged from 8.66 to 10.88 months). The results from this study have shown the potential for barramundi from the southern Gulf of Carpentaria to be aged quickly and accurately by using FT-NIR.

This study assessed handling practices and microbiological contamination of salted sun-dried Nile Perch, Lates niloticus, commonly known as Kayabo in Tanzania. The processors of Kayabo were small-scale processors located at Kanyama and Mwaloni, Mwanza. Mixed methods (observations, face-to-face interviews, and microbiological sampling) were used to assess handling practices of processors and microbiological quality of Kayabo. Hierarchical cluster analysis on handling practices of Kayabo processors produced three distinct clusters of 15 (Cluster I), 10 (Cluster II), and 5 (Cluster III) processors. In general, the majority of processors had inadequate training on appropriate food handling, lack of hygienically designed facilities (building and cooling), poor sanitation, and the use of low-quality raw materials (rejects from industrial processing units). Assessment of microbiological quality of Kayabo indicated a significant (P

This study reports on the status of metazoan fish parasites in Lake Victoria following the establishment of introduced Lates niloticus (Latidae) and Oreochromis niloticus (Cichlidae) and changes in environmental quality. For this study, 412 fish specimens were examined for parasites: 103 L. niloticus, 165 O. niloticus, 82 Haplochromis piceatus and 62 H. humilior (endemic cichlids). In total, 25 parasite taxa were identified: Lates niloticus (6), O. niloticus (19) and Haplochromis spp. (13). The myxosporean Henneguya ghaffari, prevalence (P) = 79% and the monogenean Diplectanum lacustris (P = 34%), were the dominant parasites on L. niloticus. Myxobolus sp. (P = 44%) was dominant on O. niloticus while for the haplochromines, metacercariae of 'Neascus' sp. (Diplostomidae) was dominant (P = 37%). Contrary to reports of high diversity of monogeneans on endemic species, the haplochromines harboured only Cichlidogyrus gillardinae (P = 6.9%). Oreochromis niloticus harboured seven monogenean species: Cichlidogyrus sclerosus, C. halli, C. tilapiae, C. quaestio, Scutogyrus longicornis, Gyrodactylus cichlidarum and G. malalai-they appear to have been co-introduced with the fish. Cichlidogyrus gillardinae, C. quaestio, G. malalai and the acanthocephalan Acanthogyrus (Acathosentis) tilapiae are recorded for the first time in Lake Victoria, representing new geographical records. Presence of A. (A) tilapiae in Haplochromis spp. indicates possible spillover from O. niloticus. Low prevalence and diversity of monogeneans, crustaceans and glochidia on the fish corresponded with increased pollution in the lake. Overall, changing environmental conditions and introductions of fish species have contributed to parasite community changes in Lake Victoria.

The study on a survey of fish fauna distributions and abundance in Gwaigwaye Reservoir, Katsina State was carried out from May 2013 to April 2014 to establish physical, chemical, and biological parameters (fish) of Gwaigwaye reservoir. Four sampling stations were selected. Some physico-chemical parameters were also determine to assess the level of pollution of the reservoir using standard methods and procedures which were correlated with the different fish species to determine fish abundance and distributions. Analysis of variance indicates no significant difference in fish fauna distribution and abundance among the four stations (P>0.05). The result indicated Fish fauna percentage composition were Tilapia zilli (17.32%), Clarias gariepinus (16.17%), Oreochromis niloticus (15.27%), Lates niloticus (13.80%), Bagrus. bayad (12.91%), Momyrus senegalensis (9.90%), Labeo senegalensis (7.41%) and Synodontis clarias (7.28%).

One of the essential factors to be addressed in the development of aquaculture is the feeding regime. This study was investigated to assess the effects of feeding rate on growth performance, feed utilization, chemical body composition survival rate, cannibalism and morphological indices of Asian Seabass, Lates calcarifer. Intended for the trial, one hundred forty sea bass individuals with an average weight 5.47 ± 0.11 g were randomly distributed in 4 concrete tanks (914 cm × 183 cm 122 cm) each; length × width × depth) and volume 18,399 L, for total 68 days. The fishes were fed with a pelleted diet containing 46% crude protein for different feeding groups designated as (T1, T2, T3 and T4). The feed was supplied with a rate of (T1) 3%, (T2) 4%, (T3) 6%, and (T4) 9% of fish biomass per day and feeding frequency were maintained three times per day to all the groups. At the end of the trial water physicochemical parameters was in acceptable range for Asian sea bass growth. The average daily weight gain (g), weight gain (g) and specific growth rate (%) was significantly higher (p

The study was carried out to determine the phenotypic characters of Aeromonas isolates from fresh water fishes sold in FCT using culture and isolation, and conventional biochemical identification method and confirmation with MicrobactTM GNB 24E identification system. Out of 400 samples collected from different fishes (257 from Tilapia zillii, 77 from Clarias gariepinus, 58 from Lates niloticus, and 8 from Alestes nurse) culture and biochemical characterization revealed that 40 isolates were Aeromonas specie and all the isolates (100%) were positive to oxidase, catalase, hydrogen sulphide, voges proskauer and motility tests. MicrobactTM GNB 24E kit further revealed 15 out of 40 isolates were Aeromonas hydrophila. Descriptive statistics of the results showed an overall prevalence rate of 3.75% with the highest prevalence rate of 6.79% in Bwari Area Council, 3.29% in Abuja Municipal Area Council. Aeromonas hydrophila was isolated from all the species of fish in the study area. Tilapia zillii had a prevalence rate of 3.11%, while Lates niloticus 5.17%, Clarias gariepinus, 3.89%, and Alestes nurse was 12.50%. Our research was able to isolate Aeromonas hydrophila from fresh water fish sold in Federal Capital Territory, which causes zoonotic diseases therefore implies potential danger to man and other animals which makes public health awareness and enlightenment of the dangers associated with Aeromonas hydrophila in Nigeria necessary.

Asian seabass, Lates calcarifer farming in Southeast Asia, encounters serious disease challenges caused by Streptococcus agalactiae and Streptococcus iniae. However, a vaccine for disease prevention is not yet available. In this study, we investigated the mucosal and systemic antibody (IgM) response kinetics of the Asian seabass following primary immunization with oil-based formalin-killed vaccines (FKVs) prepared from S. agalactiae and S. iniae (monovalent Sa, monovalent Si, and bivalent Sa-Si) and secondary booster with the respective water-based FKVs. The efficacy of vaccines was subsequently evaluated by an experimental challenge. The results revealed similar antibody response kinetics in both systemic and mucosal systems. However, the immune response in the fish vaccinated with the monovalent vaccines was superior to those fish received the bivalent vaccine in terms of specific antibody titer. The fish that received monovalent vaccines required 1-2 weeks to raise a significant level of specific antibody titer in both systemic and mucosal systems while those vaccinated with bivalent vaccine required three weeks. Following booster at day 21, both systemic and mucosal antibody titers in all vaccinated groups had reached the peak at day 28 and gradually declined in the following weeks but remained significantly higher than control until the end of the experiment (day 63). In the challenge test, both monovalent and bivalent vaccines were found to be highly efficacious, with the relative percentage survival (RPS) ranging from 75 to 85%. In summary, this study explored the 63-days antibody response kinetics (both mucosal and systemic systems) of Asian seabass to monovalent and bivalent inactivated vaccines and confirmed that the combination of S. agalactiae and S. iniae in a single injectable vaccine is possible.

This study investigated the quantities and qualities of fish oil extracted from five freshwater fish species, Lates niloticus, Cyprinus carpio, Clarias gariepinus, Protopterus aethiopicus, and Oreo...

Asian sea bass, Lates calcarifer is one of the most valuable marine fish species that is known to be tolerant to wide range changes of salinity. The species is able to live in freshwater, brackish and marine water, being an ideal model species for studying the effects of salinity on physiological responses. The present study is aimed to evaluate the changes in expression levels of Na+ -K + ATPase (NKA) and Na+/K+/2Cl– (NKCC) genes in gill tissue of L. calcarifer kept in a range of salinities including freshwater (0 ppt), brackish water (15 ppt) and saline marine water (35 and 50 ppt). Totals of 180 individuals were randomly distributed into 12 fiberglass tanks (volume 300 L) that contained different water salinity variants. After 30 days of experimental captivity, fish were euthanized and gill tissues were collected for NKA and NKCC mRNAs expression analysis. The U shape expression pattern for both NKA and NKCC was recorded. The highest brachial expression was seen in 50 ppt that was statistically different from all other salinity variants. The lowest expression was recorded in 35 ppt. In turns, observed NKA and NKCC expression levels in freshwater were significantly higher than 15 and 35ppt. The current findings showed that the expression levels of major gill transporters, as are NKA and NKCC has the highest expression in unusual conditions, having the lowest expression levels under the most habitual salinity conditions present in the wild environment.

Riverine ecosystems are continuously been compromised by human activities resulting in threatening their integrity. In this study, integrity of Upper Victoria Nile River was assessed using habitat quality and fish biotic indices. Experimental gillnetting was done bi-annually in 9 stations along the river from 2008 to 2018. Nine habitat metrics were used to estimate habitat quality index at every sampling station. Fish sampled, were sorted, identified to species level, and weighed. Counts of introduced and indigenous as well as tolerant and intolerant species were recorded to generate species richness. A total of 10.642 fish, 65 species belonging to nine families were recorded. Dominant species were Lates niloticus 62.79%, Oreochromis niloticus 23.51%, Mormyrus kannume 13.64%; other species were ≤0.06%. Tolerance and trophic guild showed carnivores (61.5%), omnivores (21.5%) and detrivores (16.9%).Mean habitat quality index, total fish catch and fish-based index of biotic integrity varied among stations with highest record of 26.6±6.9, 289.2±51.8 and 30.6±7.9 at sampling station (ST4) respectively. The lowest was 19.4±7.3, 93.1±13.2 and 26.7±6.8 at sampling station (ST2) respectively. On a spatial basis, indices recorded significant differences among stations (p < 0.05). Results indicated a fair fisheries biodiversity that need better conservation management of habitat type of the upper Nile.