Fish Blood Research Articles

Mercury in blood, hair, and feces from subsistence fish-eating riverines of the Madeira River Basin (Western Amazon)

BackgroundThe Madeira River (Amazon Basin) has been impacted by activities related to artisanal and small-scale gold mining (ASGM), deforestation and burning (for timber, agriculture, and hydroelectric dam projects). All these activities contribute to environmental mercury (Hg) release and cycling into the Amazon ecosystem and thus to changing lifestyles. MethodWe assessed exposure to total and MeHg in two small riverine communities of the Madeira River (Amazon): Lago Puruzinho (LP, n = 26 families) and São Sebastião do Tapurú (SST, n = 31 families). Samples of human hair (n = 137), blood (n = 39), and feces (n = 41) were collected from adults and children (0–15 years of age). ResultsIn women of childbearing age from LP village, the mean blood total-Hg (THg) (45.54 ± 24.76 μg.L−1) and MeHg (10.79 ± 4.36 μg.L−1) concentrations were significantly (p = 0.0024; p < 0.0001, respectively) higher than in women from SST village (THg: 25.32 ± 16.75 μg.L−1; MeHg: 2.32 ± 1.56 μg.L−1) village; the trend in hair-Hg persisted but was statistically significant (p < 0.0145) only for THg (LP, 11.34 ± 5.03 μg. g−1; SST, 7.97 ± 3.51 μg. g−1). In women, the median hair:blood ratio of total Hg was 269. In children, the mean hair THg concentrations were 6.07 ± 3.60 μg. g−1 and 6.47 ± 4.16 μg. g−1 in LP and SST; thus, not significantly different (p = 0.8006). There was a significant association (p < 0.001) between hair-Hg concentrations of mothers and their respective children. The excretion of Hg in feces of women (0.52 μg. g−1 dw) was not significantly different from children (0.49 μg. g−1 dw). The only statistically significant correlation between Hg in feces and in hair was found in children, (n = 16, rs = 0.38, p = 0.005). Significant relationship was seen between the levels of THg in blood and hair of women from LP and SST. Based on hair-Hg concentrations, fish consumption rate ranged from 94.5 to 212.3 g.day−1. ConclusionWomen and children excrete THg in feces in comparable concentrations. However, the mean fish consumption rate and blood MeHg are higher in the most remote villagers. Mother`s hair-Hg concentration is a good predictor of children’s hair-Hg.

Some Physiological and Biochemical Studies on Marine Fishes Rearing in Suez Canal Fish Farms

The present work was done to elucidate the impact of water quality in private fish farm in Suez Canal area and agricultural drainage water supply source (sectors A and B), Samples of three different fish species: seabream (Sparus aurata), Seabass (Dicentrarchus labrax), and Meagre (Argyrosomus regius) (sectors C, D and E), on the fish physiology, blood picture, biochemistry and accumulation of heavy metals in flesh and gills of the reared fishes. It was found that, water temperature in the different fish farm sectors around the year were significantly different, however, the pH was slightly basic. In spite of the water dissolved oxygen was around the suitable limits, its minimum value was recorded in the fish farm sector (C). Nonetheless, in this fish farm the maximum levels of salinity and total dissolved salts were recorded. Similarly, the ammonia, nitrite and nitrate concentrations were revealed in this fish farm. The relative dominance of heavy metals in the pond's water of the three investigated fish farm sectors all over the period of the study was Fe, Cu, Pb and Cd. However, heavy metals are highly accumulated in fish flesh of all fish farm sectors than in its water column. The muscle content of the detected heavy metals which accumulate in all examined fish species muscle and gills not exceeded the permitted value suggested by FAO/WHO. Metal pollution index realized its minimum levels in water and fish tissue. It is obvious that, the levels of all heavy metals detected in water samples and S. aurata, D. labrax and A. regius muscle tissues (the edible portion of fish) were under the notified permissible limits. Some of the measured parameters slightly exceeded the permissible limits recommended by regulatory agencies

Construction and Characterization of an Aeromonas hydrophila Multi-Gene Deletion Strain and Evaluation of Its Potential as a Live-Attenuated Vaccine in Grass Carp.

Aeromonas hydrophila is an important pathogen that causes motile Aeromonas septicemia (MAS) in the aquaculture industry. Aerolysin, hemolysin, serine protease and enterotoxins are considered to be the major virulence factors of A. hydrophila. In this study, we constructed a five-gene (aerA, hly, ahp, alt and ast) deletion mutant strain (named Aeromonas hydrophila five-gene deletion strain, AHFGDS) to observe the biological characteristics and detect its potential as a live-attenuated vaccine candidate. AHFGDS displayed highly attenuated and showed increased susceptibility to fish blood and skin mucus killing, while the wild-type strain ZYAH72 was highly virulent. In zebrafish (Danio rerio), AHFGDS showed a 240-fold higher 50% lethal dose (LD50) than that of the wild-type strain. Immunization with AHFGDS by intracelomic injection or immersion routes both provided grass carp (Ctenopharyngodon idella) significant protection against the challenge of the strain ZYAH72 or J-1 and protected the fish organs from serious injury. Further agglutinating antibody titer test supported that AHFGDS could elicit a host-adaptive immune response. These results suggested the potential of AHFGDS to serve as a live-attenuated vaccine to control A. hydrophila infection in aquaculture.

Biological effects of multimetal (Ni, Cd, Pb, Cu, Cr, Zn) mixture in rainbow trout Oncorhynchus mykiss: Laboratory exposure and recovery study

The present study tested the biological consequences of exposure to a multimetal mixture as a multiple chemical stressor on Oncorhynchus mykiss at molecular, cellular, physiological and whole-organism levels and on biomarker responses of this fish during the depuration period. To represent environmentally relevant multiple chemical stressors, in our study, we used the mixture of Zn, Cu, Ni, Cr, Pb and Cd at the concentrations corresponding to Maximum-Permissible-Concentrations (MPCs) acceptable for the EU inland waters. This study was undertaken with a view to elucidate if changes in the MPC of the test mixture components (Ni, Pb, Cd) could cause significantly different biomarker responses in O. mykiss from those previously determined in the carnivorous and omnivorous fishes exposed to the mixture of the same metals but at different MPCs of Ni, Pb and Cd. This study has revealed that exposure to mixtures of metals at MPC produces genotoxic effects in fish blood erythrocytes and a lethargic effect on O. mykiss behaviour, and, also, significantly increases the levels of Cd, Cr and Ni accumulated in the gills tissue. O. mykiss successfully depurated Cr and Ni in less than 28 days, however, the level of Cd decreased by only approximately 40% over the same period. A significant capacity of O. mykiss to restore its DNA integrity (Comet assay) after exposure to metal mixtures was revealed. However, the 28-day recovery period proved to be insufficiently long for erythrocytes with nuclear abnormalities to recover to the unexposed level. In conclusion, changes in the MPCs of Ni, Pb and Cd in the test mixture produce biological effects similar to those previously determined in S. salar, R. rutilus and P. fluviatilis exposed to the mixture of the same metals but at lower MPCs of Ni and Pb and at higher MPC of Cd.

Mutagenicity and genotoxicity in juvenile African catfish, Clarias gariepinus exposed to formulations of glyphosate and paraquat.

The aquatic ecosystem is under increasing pressure from environmental contaminants due to anthropogenic activities. This study investigated the potential of glyphosate and paraquat to induce DNA damage and other cell abnormalities in juvenile African Catfish, Clarias gariepinus. Juvenile fish were exposed for 96 h to 0.36, 0.48, 0.60, 0.72 and 0.84 mg/L glyphosate; and 0.018, 0.037, 0.055, 0.110 and 0.221 mg/L paraquat. Following the exposure, the fish liver and blood were analysed for DNA damage and micronucleus respectively. DNA damage was analysed using comet assay while the micronucleus test was used for assessing nuclear abnormalities. Both herbicides induced DNA damage in fish, with paraquat exhibiting higher toxicity. The severity in liver DNA damage was observed to be dependent on concentration. The herbicides triggered formation of micronuclei, bean-shaped cells, lobed nuclei, and apoptosis in blood cells of fish. Both herbicides also increased the frequency of occurrence of these cell abnormalities in erythrocytes and showed mutagenic potential in fish. Glyphosate and Paraquat both have mutagenic potentials in fish and this is a reflection of the threat these contaminants pose to fish and other forms of aquatic life in our natural water bodies. Low concentrations of these herbicides should be encouraged when usage is inevitable.

Blood Will Tell: What Hematological Analyses Can Reveal About Fish Welfare.

Blood analyses provide substantial information about the physiological aspects of animal welfare assessment, including the activation status of the neuroendocrine and immune system, acute and long-term impacts due to adverse husbandry conditions, potential diseases, and genetic predispositions. However, fish blood is still not routinely analyzed in research or aquaculture for the assessment of health and/or welfare. Over the years, the investigative techniques have evolved from antibody-based or PCR-based single-parameter analyses to now include transcriptomic, metabolomic, and proteomic approaches and from hematological observations to fluorescence-activated blood cell sorting in high-throughput modes. The range of testing techniques established for blood is now broader than for any other biogenic test material. Evaluation of the particular characteristics of fish blood, such as its cell composition, the nucleation of distinct blood cells, or the multiple isoforms of certain immune factors, requires adapted protocols and careful attention to the experimental designs and interpretation of the data. Analyses of fish blood can provide an integrated picture of the endocrine, immunological, reproductive, and genetic functions under defined environmental conditions and treatments. Therefore, the scarcity of high-throughput approaches using fish blood as a test material for fish physiology studies is surprising. This review summarizes the wide range of techniques that allow monitoring of informative fish blood parameters that are modulated by different stressors, conditions, and/or treatments. We provide a compact overview of several simple plasma tests and of multiparametric analyses of fish blood, and we discuss their potential use in the assessment of fish welfare and pathologies.

Trypanosomatids of four Loricariidae fish species in western Amazon rivers

The presence of trypanosomatids in fish is well known and can occur in many fish species worldwide. In this sense, this study aims to report the occurrence of Trypanosoma sp. in four species of the Loricariidae family in the western Amazon, as well as the morphology of these hemoparasites. The fish were collected in three sub-basins of the states of Acre and Amazonas, Brazil. Fish blood samples were collected by cardiac puncture, with smears made for quantification, morphometric measurements, and morphotyping of the trypanosomes found. We estimated the prevalence and parasitism density data. The morphometric variables of Trypanosoma sp. were subjected to analysis of variance. We found new reports of Trypanosoma distribution and occurrence in Loricariidae species for western Amazonia. The examined fish showed infection by more than one Trypanosoma spp. morphotype A has been identified infecting Loricariichthys anus, Sturisoma cf. robustum, and Loricaria cataphracta, morphotype B occurred in all fish species, and morphotypes C, D, and E occurred only in Loricaria sp. There was a significant difference between the morphotypes according to the morphometric parameters. Thus, this study significantly clarified the morphological variation, distribution, and diversity of Trypanosoma hosts.

АДАПТИВНЫЕ ИЗМЕНЕНИЯ КАРТИНЫ КРОВИ КЛАРИЕВОГО СОМА НА ФОНЕ ТРЕКРЕЗАНА ПРИ ВЫРАЩИВАНИИ В ИСКУССТВЕННОЙ СРЕДЕ

The work is devoted to the study of trecresan adaptogen effect on hematological parameters of sharptooth catfish bred in an artificial environment. In particular, the effect of trecresan on general hematological parameters and antioxidant system of African sharptooth catfish was assessed, since breeding in an artificial environment is accompanied by stress, in which oxidative processes increase, leading to damage of biological membranes and disruption of cell functioning. Blood samples were analyzed using an Axio Imager.M2 microscope (Carl Zeiss, Germany). The analysis of enzymatic activity (units / mg of protein) was carried out on a UV-1800 double-beam spectrophotometer (Shimadzu, Japan). The obtained results indicate that in case of trecresan adaptogen application, there was a tendency to a proportion increase of monocytes, platelets and stab neutrophils. There is an increase of the total amount of intracel- lular hemoglobin, superoxide dismutase and catalase activity in erythrocytes and in the blood of fish bred with application of trecresan adaptogen. Trecresan induces production of interferons, increases the body immune status, activating cellular and humoral immunity, leads to a decrease of toxic products formed during lipid peroxidation by increasing the activity of enzyme unit in the antioxidant system and ensures antioxidant defense improvement of sharptooth catfish bred in an artificial environment. It strengthens the body immune system and increases resistance to adverse environmental factors. In our studies, trecresan revealed itself as a mild, effective immunomodulator.

Kelayakan tepung darah dalam pembuatan pakan untuk pertumbuhan ikan nila, Oreochromis niloticus)

The purpose of this study was to determine the feasibility of blood meal in various level inclusins in promoting the growth rate and nutrient utilization of O. niloticus. The results showed that the absolute growth of tilapia in treatment 2 (with a combination of 20%) was higher than the other treatments. The daily growth rate of tilapia in treatment 2 (3.5% / day) was higher than other treatments. Likewise, with the feed change value, treatment 2 showed significantly different from other treatments. The combination of tuna fish meal waste and blood meal showed significantly different results from the results of statistical tests

Water quality and health status of the monosex Nile Tilapia, Oreochromis niloticus cultured in aquaponics system (ASTAF-PRO)

The present study is a part of a cooperative project to enable the efficient transfer of innovative ecotechnology ASTAF-PRO aquaponic from Germany to Egypt for sustainable aquaculture and food production. The present part was carried out to evaluate the impact of ASTAF-PRO aquaponic system on water quality parameters and the health status of the monosex Nile tilapia Oreochromis niloticus. Water quality analysis revealed an improvement of most parameters in an aquaponic system with a significant reduction in toxic ammonia. In aquaponic, the nitrite level in ASTAF-PRO was lower than the permissible limit, probably because of the double-sided action of nitrobacteria present in the biological filters and the grow beds of the plant in the system. No significant difference was observed in the values of nearly all the hematological parameters in the blood of fishes reared in the aquaponic system and those reared in POND systems, being always within the normal ranges for the healthy Nile tilapia. Most of the measured biochemical variables exhibited an improvement in the blood of fish reared in the ASTF-PRO system compared to that of the POND. This suggests that fish health improved when reared in aquaponic with better water quality parameters. Immunoglobulin (IgM) levels and lysozyme activity were the same in the blood of fish reared in both systems, confirming that the monosex Nile tilapia was still fit with a good immunological status under aquaponic condition. In conclusion, the health status of the monosex Nile tilapia reared in ASTAF-PRO aquaponic system was better than those reared in POND in terms of hematology, biochemistry and immunological status. Obviously, the difference in the health status of fish in different systems can be linked to water quality since the same feed was used.

Family-effects in the epigenomic response of red blood cells to a challenge test in the European sea bass (Dicentrarchus labrax, L.)

BackgroundIn fish, minimally invasive blood sampling is widely used to monitor physiological stress with blood plasma biomarkers. As fish blood cells are nucleated, they might be a source a potential new markers derived from ‘omics technologies. We modified the epiGBS (epiGenotyping By Sequencing) technique to explore changes in genome-wide cytosine methylation in the red blood cells (RBCs) of challenged European sea bass (Dicentrarchus labrax), a species widely studied in both natural and farmed environments.ResultsWe retrieved 501,108,033 sequencing reads after trimming, with a mean mapping efficiency of 73.0% (unique best hits). Minor changes in RBC methylome appeared to manifest after the challenge test and a family-effect was detected. Only fifty-seven differentially methylated cytosines (DMCs) close to 51 distinct genes distributed on 17 of 24 linkage groups (LGs) were detected between RBCs of pre- and post-challenge individuals. Thirty-seven of these genes were previously reported as differentially expressed in the brain of zebrafish, most of them involved in stress coping differences. While further investigation remains necessary, few DMC-related genes associated to the Brain Derived Neurotrophic Factor, a protein that favors stress adaptation and fear memory, appear relevant to integrate a centrally produced stress response in RBCs.ConclusionOur modified epiGBS protocol was powerful to analyze patterns of cytosine methylation in RBCs of D. labrax and to evaluate the impact of a challenge using minimally invasive blood samples. This study is the first approximation to identify epigenetic biomarkers of exposure to stress in fish.

Redescription of the Type Species of Cardicola Short, 1953 (Digenea: Aporocotylidae) and Description of a New Congener Infecting Yellowedge Grouper, Hyporthodus flavolimbatus (Perciformes: Serranidae), from the Gulf of Mexico.

Cardicola Short, 1953 is the most speciose aporocotylid genus (35 species) and includes marine and estuarine species of fish blood flukes that infect "higher ray-finned fishes" (Euteleostei). Several clades within Cardicola are recovered in phylogenetic analyses of the large subunit ribosomal DNA (28S), but morphological synapomorphies for those nucleotide-based clades remain elusive. The type species, Cardicola cardiocola (Manter, 1947) Short, 1953, has not been recollected in 73 yr and the original description was incomplete; making a genus revision challenging because of the ambiguous systematic position of its type species. Herein, we redescribe C. cardiocola by using the holotype (USNM 1337732) and new specimens collected from the type host, jolthead porgy, Calamus bajonado (Sparidae), from nearby the type locality. It differs from its congeners by the combination of having a body that is 5 times longer than wide, an anterior sucker with concentric rows of spines, 2-6 tegumental body spines per row, an esophageal gland that is 22-43% of the esophageal length, a testis that is 3-5 times longer than wide and that fills the intercecal space, a vitelline duct connecting to the anterior aspect of the oötype, an ascending uterus that lacks any coil, a descending uterus yielding a single coil, an obvious cirrus sac separated by constriction from the seminal vesicle, a tegumental protrusion surrounding the terminal end of cirrus sac, and a male genital pore that is posterior to the remainder of the genitalia. We also describe a new congener infecting the heart of yellowedge grouper, Hyporthodus flavolimbatus (Serranidae), from the Gulf of Mexico. It differs from its congeners by the combination of having an anterior sucker that does not extend beyond the anterior body margin, 2-5 tegumental body spines per row, posterior ceca that are 9 times length of the anterior ceca and that lack any coil, a testis that is 3 times longer than wide and that does not fill the intercecal space, an ovary that is >60% of the body width, a vitelline duct that connects to the anterior aspect of the oötype, a uterus that is >10% of the body width and that extends posterior to all genitalia, and a rounded posterior body margin. It is the first species of Cardicola to be described from a grouper (Serranidae). The 28S and internal transcribed spacer 2 phylogenetic analyses recovered the new species as a distinct lineage within the clade of Cardicola spp.

The role of corals on the abundance of a fish ectoparasite in the Great Barrier Reef

Gnathiid isopods, common fish ectoparasites, can affect fish physiology, behaviour and survival. Gnathiid juveniles emerge from the benthos to feed on fish blood. In the Caribbean, gnathiids are positively associated with dead coral and negatively associated with live coral, due to coral predation on gnathiids. However, such interactions were unstudied in the Great Barrier Reef (GBR). Due to recent extreme weather events (two cyclones and one mass warm-water coral bleaching event, 2014–2016), it is now urgent to understand the role of corals on the abundance of these ectoparasites. Here, to understand parasite–coral dynamics at the micro-habitat level, we examined substrate associations of gnathiid isopods on Lizard Island (GBR) using demersal plankton emergence traps. Additionally, we determined whether two abundant hard coral species, Goniopora lobata and Pocillopora damicornis, predate on gnathiids in a laboratory experiment using containers with gnathiids and fragments from each coral species or dead coral as controls. The abundance of gnathiids over natural substrates was higher for dead compared to live hard coral and sand, but not live soft coral. Moreover, we found that free-swimming gnathiids decreased in containers with live coral compared to dead coral controls. This was attributed to predation as we also directly observed a coral ingesting a gnathiid. Our results suggest that dead coral is a suitable microhabitat for gnathiids, but that live coral is not since live corals can predate on gnathiids. We propose that following extreme events, such as cyclones and heat waves, gnathiids might benefit from more dead coral substrate and a decrease in predation by the reduction in coral cover on the reef. We advocate that an increase in the frequency of extreme events may have cascading effects for the fish population through changes in the population of benthos-dependent ectoparasites.

Effect of the hyperosmotic infiltration method on immune response in tilapia vaccinated with Streptococcus agalactiae

This study aimed to evaluate the immune response in tilapia (Oreochromis niloticus) in optimum salinity for a vaccination with hyperosmotic infiltration in controlling streptococcosis caused by Streptococcus agalactiae. A total of 100 fish weighing 4.26 ± 1.37 g were immersed in water with a salinity of 0, 10, 20, and 30 g L−1 for 5 min, and then immersed in 109 cfu L−1 S. agalactiae vaccine for 30 min. The challenge test was carried out on 31 days post-vaccination with pathogenic S. agalactiae. Relative percent survival, blood profile, antibody titer, lysozyme activity, and fish blood glucose were measured on day 0, 15, and 30 post-vaccination and 10 post-challenge tests. The results showed that hyperosmotic infiltration with 20 g L−1 resulted in a higher relative percent survival of 88.24% compared to other treatments. Immunological parameters such as total erythrocytes, total leukocytes, hemoglobin levels, hematocrit levels, phagocytic activity, lysozyme as the non-specific immune system, and antibody levels as a specific immune system in fish immersed at 20 g L−1 before vaccination were higher than others. In conclusion, fish immersed in 20 g L−1 before immersion vaccination enhanced non-specific and specific immune defense and increased fish protection against pathogenic S. agalactiae.

Intra and extracellular effects of benzo [α] pyrene on liver, gill and blood of Caspian White fish (Rutilus frissi kutum): Cyto-genotoxicity and histopathology approach

Southern parts of the Caspian Sea have been faced with a diverse range of oil pollutants. Therefore, this study was designed to evaluate the effects of relevant environmental concentrations of benzo[α]pyrene (BαP) on liver, gill, and blood of Caspian White fish. To this end, 150 fingerling fish (6.5 ± 0.8 g) were exposed to under, near and over environmental concentrations of BαP (i.e. 50, 100, and 200 ppb, respectively) and two control groups for 21 days. Following exposure to BαP, generally, DNA damage increased in the liver and gill cells as well as the frequency of micro- and bi-nucleated erythrocytes in a time and concentration-dependent pattern. In addition, the liver and gill tissues displayed several histopathological lesions. Together, the findings are warning the health status of the Caspian Sea due to an ever-increasing concentration of BαP through using Caspian White fish as an ecological model.

Flow cytometry in the analysis of hematological parameters of tilapias: applications in environmental aquatic toxicology

Blood tissue has been used to assess animal health and the environment in which they live. This tissue is easily acquired and has the ability to respond to various adverse conditions. Several techniques have been employed in the detection of xenobiotic-induced cell damage in blood cells. In general, traditionally used technologies, such as cellular analysis in blood smears, are time-consuming and require great analytical capacity. The present study proposes flow cytometry as a method to detect changes in blood cell populations. Tilapia (Oreochromis niloticus) was selected as a model for plotting the profile of fish blood cell populations after exposure to xenobiotics without euthanizing animals or using cell markers. Populations of erythrocytes and lymphocytes were detected only by combining the techniques of FACSAria cell sorting and light microscopy. Systemic deleterious effects were found through blood analysis, such as an increased lymphocyte-rich population at 48 h of exposure followed by a subsequent decrease. Moreover, the time-dependent expression of Nrf2 suggests its participation in increased membrane disruption, indicating it has a central role in erythrocyte lifespan. The present results shed light on the viability of using flow cytometry for blood analysis of living fish.

CYTOGENETIC ANALYSIS OF NUCLEAR ANOMALIES OF ERITHROCYTES OF COMMON CARP (CYPRINUS CARPIO)

Blood of fish is a highly sensitive system that quickly responds to the effects of toxins and other stress factors of abiotic and biotic nature. Among the various pathologies of fish blood the formation of micronuclei and anomalies of the nucleus of erythrocytes are distinguished, which can act as markers of the stability of the genome of aquatic life. Therefore, this work presents a cytogenetic analysis of nuclear abnormalities in erythrocytes of common carp. In fish under investigation, erythrocytes with micronuclei, with a budding and bubbling nucleus, erythrocytes with a caudate filamentous and coracoid nucleus, and cells with a bilobed nucleus were detected. In the blood such types of nucleus anomalies as erythrocytes with a budding and bubbling nucleus prevailed, constituting 0.16 ± 0.031 and 0.28 ± 0.153%, respectively. The average total level of pathologies of the nucleus of erythrocytes in the studied carp was 0.89 ± 0.202%, which corresponded to the parameters of healthy fish.

Effect of Different Stocking Density of Snakehead Fish (Channa striata) Cultured in Recirculation Aquaculture System

In Indonesia, the use of such recirculating aquaculture systems (RAS) is rapidly increasing. The purpose of this study was to investigate the growth, blood chemistry, and water quality of snakehead fish (C. striata) maintained in RAS at varied stocking densities. The RAS was established at the Bogor-based Research Institute for Freshwater Aquaculture and Fisheries Extension. The study employed a completely randomized study using 3 various densities: A). 1 individual L-1, B). 3 individual L-1 and c). 6 individuals L-1, each using three replications. The average weight and length of snakehead fish used is 1.50±0.63 g and 6.20±0.94 cm. Growth performances such as survival rate, weight, and length gain, food conversion ratio, specific growth rate, and final biomass were observed during the research. Blood chemistry parameters analyzed were blood glucose, triglycerides, and total protein. The water quality characteristics were evaluated: pH, temperature, dissolved oxygen, total ammonia nitrogen, nitrate, nitrite, and orthophosphate. The analysis indicates that snakehead fish's growth performances and blood chemistry parameters differed considerably (P&lt;0.05) across all density treatments, with 3 individual L-1 showing the best growth performances. The RAS utilized in snakehead fish culture kept the water quality parameters steady throughout the study.

Efficacy of Probiotics Supplementation on Growth Performance, Carcass Composition and Hematological Parameters of Cyprinus carpio Fingerlings Fed Corn Gluten Meal-Based Diet

Abstract Plant based protein sources are one of the best, cost effective and easily available protein sources being used in fish feed. But due to a lower number of micro-biota in fish gut plant meal based diets cannot be digested and absorbed well in fish body. Probiotics were supplemented at 0, 1, 2, 3, 4 and 5 gkg-1 levels in fish feed for formulating one control and five test diets. In this study, three replicates of each treatment were used and number of fingerlings was 15 in each replicate. The C. carpio (common carp) fingerlings were fed at 5% of live wet weight on their prescribed diet twice daily. The results revealed that supplementation of probiotics in corn gluten meal based diets significantly (p<0.05) improved growth performance, carcass composition and hematological parameters. Most optimum values of growth performance parameters were noted at 2 gkg-1 level of probiotics supplemented diet. C. carpio fingerlings fed corn gluten meal based diet supplemented with 2 gkg-1 level of probiotics indicated significant (p<0.05) improvements in crude protein (17g) crude fat (9g) and gross energy (3 kcalg-1) whereas higher red blood cells (RBCs), white blood cells (WBCs) and hemoglobin (Hb) was also recorded in fish blood when fed 2 gkg-1 probiotics level diet. From these results, it was concluded that 2 gkg-1 probiotics supplementation in corn gluten meal based diet is optimum for improving growth performance, body composition and hematology of C. carpio fingerlings.

Evaluation of Haematological and Biochemical Changes in Catfish (Clarias Gariepinus) Fed Ginger Additive Meal Diets

Clarias gariepinus adults were fed varying levels of ginger additive meal diets (0 mg/g, 25 mg/g, 50 mg/g, 75 mg/g and 100 mg/g), respectively, in order to evaluate their effects on the biochemical and haematological parameters of fish. Blood biochemical analysis was performed at the end of 84 days by taking the portion of the collected blood and was dispensed into non-heparinised tubes. There were significant increases (P &lt; 0.05) in glucose, aspertate transferase, alanine transferase, and sodium concentrations respectively. The activity of potassium, creatinine and serum protein changed in a non-significant (P &gt; 0.05) manner with increasing concentrations of additive diets compared to the control. Although no definite trend in the values of computed biochemical indices was observed. However, glucose, aspertate transferase (AST), alanine transferase (ALT), urea, creatinine, sodium, and potassium increased with varying additive inclusion concentration. Also, Glucose, ALT, AST, Urea, creatinine, sodium and potassium activities of all the fish, which have been fed ginger additive meal diets were significantly higher (p&lt;0.05) in comparison to their respective control. Results also showed that there were increase in the blood parameters of Clarias gariepinus fed ginger additive meal diets compared to the control diet except in mean cell haematocrit (MCV) but were statistically different (p&lt;0.05). Highest Packed cell volume (PCV) of 31.00% were recorded in diet (GD3), White Blood Cell (WBC), 8.00 x 103 in GD2, and red blood cell (RBC) 8.70 x 106; while highest Haemoglobin (Hb), 11.00 g/dl were recorded in fish fed diet GD3. All blood parameters obtained were between the range of recommended fish blood. It is concluded that using ginger as additive feed on Clarias gariepinus showed a slight increase in the haematological parameters compared with the control diet (GD1) except in MCV but it has no negative effect on the health status of the studied fish.