Juvenile Catfish Research Articles

CANNIBALISM PERFORMANCE OF ASIAN REDTAIL CATFISH (Hemibagrus nemurus) FED RATION SUPPLEMENTED WITH DIFFERENT DOSES OF 17α-METHYLTESTOSTERONE

One of the obstacles in Asian redtail catfish hatchery is the high cannibalism incidence. Cannibalism is associated with aggressive behavior caused by hormonal metabolism especially of testosterone. The purpose of this study was to evaluate the effect of testosterone administration on the cannibalism incidence in the Asian redtail catfish juveniles. The experiment was conducted by rearing fish with initial length of 4.09±0.19 cm in 16 of 20 L aquariums with a density of 2 fish L-1. The experiment was designed with a completely randomized design with 4 treatments which were different level of 17α-methyltestosterone supplementation in feed, i.e., 0 mg kg-1 feed (A) as control, 7.5 mg kg-1 feed (B), 15 mg kg-1 feed (C), and 30 mg kg-1 feed (D). Each treatment has 4 replications. Fish fed experimental diet (40% protein) 4 times a day to satiation for 30 days. The parameters observed were type and index of cannibalism, aggressive behavior, survival rate, normal mortality, growth performance, hormones concentrations (estradiol, testosterone, and cortisol), and water quality. The results showed that cannibalism type II (the fish eaten completely or missing) and cannibalism index increased with the increasing doses of testosterone administration in the feed with the highest cannibalism incidence was 40.63%. The highest survival rate was found in treatment B (73.75±2.50%) and was not significantly different from the control treatment (69.38±2.39%). No differences in testosterone concentration and in the growth performance among the treatments. However, there was a trend of decrease in the estradiol concentration of Asian redtail catfish juveniles fed ration supplemented with the increasing doses of 17α-methyltestosterone. Based on the results obtained in this research, estradiol changed in the body's plasma, it appears that there was a role for plasma estradiol concentration in controlling cannibalism of Asian redtail catfish juveniles. It concluded that the testosterone administration affected the cannibalism incidence in the Asian redtail Catfish.

The efficacy of hydrolized feathermeal as a protein source in diets for juvenile catfish Ictalurus punctatus

Chicken feather meal is often viewed as an undesirable product, as most people think of ground up feathers, which have many processing and nutritional issues. However, modern feather meals are produced through a hydrolysis process which greatly improves protein digestibility. Given the poor understanding of the quality of these meals, we chose to evaluate the efficacy of hydrolyzed feather meal (HFM) as a protein source in channel catfish feeds. For this work, we investigated the replacement of either poultry-by-product meal (PBM) or soybean meal (SBM) in a practical feed formulation for juvenile catfish. The basal diet contained 6% PBM and 56.5% SBM. For the first series of diets, we incrementally replaced PBM with 2.5% and 5% hydrolyzed feather meal (HFM). The second series included five experimental diets with SBM replaced by HFM at a rate of 2.5%, 5%, 7.5%, 10%, and 15%. Diets were formulated to be iso‑nitrogenous and essential amino acids were supplemented to maintain minimal levels that met the nutritional requirements. Catfish were stocked at 15 fish per aquaria using four replicates per treatment and grown for 78 days. The survival of the catfish was above 85% across all treatments with no significant differences found due to diet. Apart from one diet, the inclusion of HFM did not influence the growth or FCR of the fish. Diet 3, which contained 5% HFM as a complete replacement for PBM had significantly lower growth and FCR than the other treatments. These results indicate that up to 20% HFM can be used in catfish feeds a as long as there is a low level of another animal protein. However, the complete replacement of PM with HFM was not successful.

Dietary inclusions of black soldier fly (Hermetia illucens) larvae frass enhanced production of channel catfish (Ictalurus punctatus) juveniles, stevia (Stevia rebaudiana), and lavender (Lavaridula angustifolia) in an aquaponic system

In aquaponic systems, adding supplemental nutrients to enhance plant production is common. Frass, which is the manure of insects, can be used to enhance fish and plant production, but no study has yet examined the potential to enhance both using a dietary approach in an aquaponic system. In this 8-week study, channel catfish (Ictalurus punctatus) juveniles were fed diets with, or without, 10% black solider fly (Hermetia illucens) larvae (BSFL) frass in an aquaponic system. Each aquaponic system had two different plant bed types; floating raft or media. Each plant bed consisted of three stevia (Stevia rebaudiana) and three lavender (Lavaridula angustifolia) plants in a 2 × 2 factorial design, with the main effects of dietary frass inclusion and media type. After 8 weeks, channel catfish grew significantly faster when fed a diet containing 10% BSFL frass compared to fish fed the control diet. Further, dietary frass upregulated the hepatic expression of IGFβ, IGF-1 and GHR as well as reduced intestinal inflammation based on histological observations and scoring. The muscle proximate composition of channel catfish was unaffected by diet, while only taurine was significantly reduced by dietary frass. Muscle calcium and phosphorus as well as C14:0 and C15:0 were significantly elevated by dietary frass. For plants, both stevia and lavender had significantly more biomass when frass was added to the system, while plants grown in media beds were larger than plants grown in a floating raft subsystem. Frass significantly increased phosphorus in both stevia and lavender at week 8. The higher water calcium, magnesium, and nitrate levels may have allowed for better plant growth as these are essential nutrients. The significant increase of catfish growth was likely due to the upregulation of genes responsible for growth, mitigating intestinal inflammation, and significantly enhancing diet intake. Thus, it may be recommended that feeding catfish with BSFL frass and culturing stevia and lavender in media beds can substantially improve overall productivity.

Hepatosomatic index and haematological profile: A bio monitoring tools for assessing african catfish juveniles (Clarias gariepinus) exposed to dimethoate 40% EC toxicity

Organosomatic and Haematological Indices are commonly reported in fisheries studies because they are easily determined and can be excellent predictors of adverse health in fish. The objective of the present study was to evaluate the toxicity effect of an organophosphate (dimethoate 40% EC) on catfish (Clarias gariepinus) juvenile using majorly two indices Hepatosomatic Index (HSI) and Haematological parameters. The fishes were exposed to three sub lethal concentrations 0.01 mg/l, 0.15 mg/l and 0.29 mg/l and monitored for 28 days. Result showed a significant decrease in the Hepatosomatic Index (HSI) of the treated groups when compared with the control recording 2.36g, 2.49g and 2.47g for 0.29mg/l, 0.15mg/l and 0.01mg/l respectively. Catfish (Clarias gariepinus) exhibited alteration which was significant (P<0.05) in the total white blood cell count amongst other checked parameters such as Red Blood Cell Count, Packed Cell Volume and Haemoglobin. Result of the study indicates potential toxicity of Dimethoate to juveniles of Clarias gariepinus for which aquatic environment must be continuously monitored.

Phytase Enzyme Improves Growth Performance and Body Chemical Composition of Sangkuriang Catfish (Clarias gariepinus var. Sangkuriang) Juvenile

Due to their nutritional value, alternative vegetable materials such as soybean are needed to promote sustainable aquaculture development. However, phytate in soybean could interfere with the protein digestion of the fish body. This study examines the effectiveness of phytate enzymes in enhancing protein digestibility, growth performance, mineral digestion, and body chemical composition of Sangkuriang catfish (Clarias gariepinus var. Sangkuriang) juveniles. The study was completely randomized design with 4 treatments and 3 repetitions. One hundred thirteen Sangkuriang catfish juveniles (7.65 ± 0.14 g) were used for each repetition. The fish were fed with an experimental diet supplemented with various doses of phytase enzyme: 0 (A), 500 (B), 1,000 (C), and 1,500 (D) FTU/kg of feed. The mineral digestibility, protein digestibility, protein efficiency ratio (PER), feed conversion ratio (FCR), the efficiency of feed utilization (EFU), apparent digestibility coefficients (ADCp), relative growth rate (RGR), and survival rate (SR) were observed. Data were analyzed using analysis of variance followed by Duncan’s multiple range test. The results showed that adding 1,000 FTU/kg of phytase enzyme (C) exhibited the highest PER, FCR, EFU, ADCp, and RGR value of Sangkuriang catfish juveniles compared to other treatments. All treatment groups (B-C) had the same SR value (100%) and had the highest crude protein and ash content compared to the A group. All group treatments also exhibited a higher phosphorus, calcium, potassium, magnesium, iron, zinc, manganese, copper, and cobalt. Therefore, phytase enzyme supplementation could improve protein digestibility, mineral digestibility, growth performance, and body chemical composition of Sangkuriang catfish juveniles.

COMPARATIVE DEVELOPMENT OF JUVENILE CATFISH (CLARIAS GARIEPINUS) FED COMMERCIAL DIETS AND MAGGOT MEAL IN RECIRCULATING AQUACULTURE SYSTEM

This study evaluated the comparative development of juvenile catfish (C.gariepinus) fed commercial diets (Skretting and Aqualis feed) and maggot meal at the Fishery unit, Federal College of Forestry Jos (FCF, Jos), Plateau State Nigeria. One hundred and twenty (120) C.gariepinus fingerlings were purchased at the Fishery unit, FCF, Jos for the experimental study. The experimental trial was conducted within 6 weeks (42days). The experimental set-up comprised three treatments; with each replicated. Data collected was evaluated using ANOVA and mean values were differentiated by the New Duncan Multiple range test at 5% (p≤0.05) probability level. Using the sack method, maggots were cultured from poultry waste and harvested using the floating method with mesh nets; then further processed into powdery form as the maggot meal. The commercial feeds and maggot meal had different proximate compositions; the maggot meal had better nutritional value and content. The C.gariepinus fingerlings in T3 indicated pre-eminent values for the growth parameters with regards to average length (6.90cm); width (6.95cm) and weight gain (0.047kg). Furthermore, the criterion of water quality in the RAS was significant and suitable for production of the juvenile catfish (C.gariepinus). Also, there are variations in the comparative cost of experimental feeds consumed during the experimental trial. This study therefore recommends increased utilization of the maggot meal formulated at 35% crude proteins as the central diet for C.gariepinus fingerlings in RAS; intensification of maggot production and extensive research on maggot meals as fingerlings diets.

Aquaponic production of strawberries: Influence of boron and media on their mineral and sugar composition

AbstractStrawberries can fetch high market prices, but this is often based on their sweetness. Previous studies have shown that sugar content in fruits is elevated by boron (B), but this has not been tested on strawberries in an aquaponic system. In this study, strawberries were aquaponically cultured with or without B supplementations and with or without media (2 × 2 factorial design) over 2 months. Each of the six identical aquaponic units contained 30 catfish juveniles (initial weight = 2.1 g) and two plant culture units; one with a floating raft (without media) and one with expanded lava rock (with media). Borax was the source of B, which was weekly added at 0.01 mg/L. Water quality and fish growth were unaffected by B additions. Total number of strawberries and their total weights were unaffected by B or media. Media caused strawberries to be individually heavier with higher sodium, iron and moisture but significantly less glucose and fructose. Supplementations of B significantly increased and decreased the B and zinc content of strawberries, respectively, as well as causing significantly shorter roots. Growing strawberries with or without media in an aquaponic system provided different advantages but B supplementations appeared unnecessary and may have caused some toxicity to the strawberries.

The Effect Of Different Feed Combinations On The Growth Rate, Efficiency And Survival Rate Of Juvenile Catfish (Clarias Sp.)

Catfish is classified as an omnivorous fish and has fast growth, has the ability to tolerate wide-ranging environmental parameters. The study aims to determine the length growth, weight growth, survival rate, feed efficiency and to determine the water duality in the Catfish (Clarias sp.) juvenile pond with differend feed treatments. The results of research showed that different feeding had an effect on the growth of catfish (Clarias sp.) juveniles. Length growth ranged from 9.78-10.8 cm, the highest value was in treatment 3, namely 10.8 cm and the lowest was in treatment 1, namely 9.78 cm. Weight growth ranged from 24-39 g, the highest value was in treatment 3, namely 39g and the lowest was in treatment 1, namely 24g. The survival rate ranged from 0.95-1%, the highest value was in treatment 3, namely 1% and the lowest was in treatment 1, namely 0.95%. feed efficiency ranged from 2.124-3.55%, the hinghest value was found in treatment 3, namely 3.55% and the lowest in treatment 1, namely 2.124%. the water quality during the research was still in the appropriate range for growth and survival of catfish (Clarias sp.) juveniles.

Effect of Hair Dressing Salon Effluent on the Juveniles of African Catfish (Clarias gariepinus)

The toxicity of hair dressing salon effluent on Clarias gariepinus juveniles was studied using static bioassay method. This study investigated haematological, histopathological and biochemical changes in Clarias gariepinus juveniles. The fish samples were distributed randomly into T1 (800 ml/L), T2 (600 ml/L), T3 (400 ml/L), T4 (200 ml/L), and T5 control (water alone). All samples were studied in three replicates, in a completely randomized experiment. Mortality increased with increased effluent concentrations; 250.96 ml/L was recorded as LC50 for 96 h. Various behavioural changes observed in fishes before death include: odd swimming patterns, jerk movements, bottom resting and loss of appetite. Histopathological changes were observed in treated fishes while the livers and gills of the control fishes showed normal histological appearance. It was concluded that hair dressing salon effluents had some negative effect on histopathology and behavioural responses of juvenile Clarias gariepinus. Therefore, it is recommended that the effluent should be properly treated before being discharged into the environment.

Haematological and Histological Assessment of Clarias gariepinus Juveniles Exposed to Crude Extract of Albizia Chevalier Sawdust

The toxicity of Albizia chevalier sawdust extract was investigated with emphasis on histopathological and haematological effects on African catfish (Clarias gariepinus) juveniles. A static bioassay was conducted to determine the LC50 of Albizia chevalier sawdust extract to Clarias gariepinus juveniles. The fish were exposed to 55, 63.1, 67.6, and 73.9mI/L of Albizia chevalier sawdust extract. The result of the acute toxicity showed that the extract was toxic to the fish with an LC50 value of 54.42mI/L. The pH, DO and temperature values of the water in the different concentrations differed significantly from the control (p ≤ 0.05). Furthermore, the haematological assessment revealed that values of the blood parameters (WBC, RBC, HGB, HCT, PCV, LYM, MxM, NEUT and PLT) of fish in the different concentrations were significantly different from the control (p<0.05). Histopathological examinations of the gills and liver of Clarias gariepinus juvenile exposed to Albizia chevalier sawdust extract in the control showed normal gill and liver architecture. However, there were varying degrees of degenerative changes in the gills and liver of fish in different concentrations of the Albizia chevalier sawdust extract. The results of the study revealed that crude extract Albizia chevalier is toxic to fish organs and causes histopathological changes in the gills and liver and cause stress to the fish. Therefore indiscriminate discharge of sawdust by sawmills into the environment should be discouraged particularly into water bodies.

Pathogenicity of Aspergillus fumigatus in Experimental Infection of Different Developmental Stages of Clarias gariepinus

Aims: This study aimed to investigating the pathogenicity of Aspergillus fumigatus in the experimental infection of Clarias gariepinus fingerlings and juvenile catfish.
 Experimental Procedure: Aspergillus fumigatus used for this study was isolated from the gills and liver of infected juveniles presented for microbial diagnostic examination, cultured on Sabouraud dextrose agar for 3 – 4 days, and identified at the Aquatic Animal and Wildlife Laboratory (AAWL), Department of Veterinary Medicine, University of Ibadan.
 Methodology: One hundred and forty healthy eight-week old Clarias gariepinus fingerlings (average weight of 4g) and 140 healthy sixteen-week old juvenile (average weight of 10g) were purchased from a commercial fish farms in Ibadan. The fingerlings and juveniles were randomly divided into seven groups, each with 20 fish in five litters of water. The fungal suspension containing 3.2 X 106 spores/ml of Aspergillus fumigatus was used for the pathogenicity test. Six groups were infected by immersion in water containing fungal spores at the rates of 2ml/L and 5ml/L for fingerlings and juveniles respectively. The clinical signs, skin lesions and mortality were observed daily for 14 days.
 Results: Aspergillus fumigatus isolated in this study has green spiked conidia; and the size of the conidia is 2.5µm. The conidia have a smooth surface and small spikes covering their surface. Moreover, the mortality rate was significantly (p = 0.40) higher in infected fingerlings (80%) than juveniles (62%) at fourteen days post-infection. The gross lesions observed during experimental infection of fingerlings and juveniles included exophthalmia, atrophied barbel, congested trunk kidney, hyperemia of gill filaments, and skin depigmentation. The histopathological organ changes caused by Aspergillus fumigatus were obvious in the liver and gills. Vacuolar degeneration of hepatocytes and necrosis of some melanomacrophage cells, in addition, severe erosion of the primary and secondary lamellae, were observed in infected juveniles.
 Conclusion: Aspergillus fumigatus causes high mortality in fingerlings and juvenile of African Catfish (Clarias gariepinus).

Lactobacillus acidophilus Supplementation Improves the Innate Immune Response and Disease Resistance of Striped Catfish (Pangasianodon hypophthalmus Sauvage, 1878) Juveniles against Aeromonas hydrophila

A bacterium Lactobacillus acidophilus (LAB) was evaluated for its probiotic potential on the health status of striped catfish (Pangasianodon hypophthalmus, Sauvage, 1878) juveniles. Triplicate groups of striped catfish (21.69 ± 0.18 g) were fed twice daily at 2.5 % of body weight, with 0 (control), 103, 105, 107 and 109 CFU/g LAB diets for 12 weeks. The fish were challenged intraperitoneally with 1×106 CFU mL−1 of Aeromonas hydrophila after 12 weeks of feeding trial and the mortalities were recorded over 21 days. The haematological, immunological parameters and histopathological changes of liver were assessed both in pre- and post-challenged fish groups. Results revealed that feeding the fish with supplemented diets significantly increased (p < 0.05) the survival after challenged with A. hydrophila. Compared to the control diet, a significant improvement in packed cell volume, red blood cell, white blood cell and lymphocyte counts were observed in LAB supplemented diets in the pre-challenged fish groups. After 3-week post challenged, the hematological parameters, immunoglobulin and survival were significantly high in fish fed with LAB supplemented diets at 105 CFU/g and above, while only the lysozyme activity was significantly high after 2-week post-infection. Histopathological result revealed that severe necrosis was found in the liver of striped catfish fed with the control diet after challenged with A. hydrophila which was not seen in the case of LAB supplemented diets. Thus, the results suggest that administration of LAB at 105 CFU/g of diet improves the innate immune response of striped catfish juveniles. HIGHLIGHTS Dietary Lactobacillus acidophilus (LAB) supplementation improved survival of striped catfish after challenge with Aeromonas hydrophila LAB supplementation enhanced the non-specific immunity of juvenile’s striped catfish LAB supplementation improved the histopathology of pre- and post-challenge liver of striped catfish juveniles GRAPHICAL ABSTRACT

Effects of Dietary Lysine for River Catfish Juveniles on Protein Digestibility and Body Composition

Effects of Dietary Lysine for River Catfish Juveniles on Protein Digestibility and Body Composition

Effects of acute heat stress on haemato-biochemical parameters, oxidative resistance ability, and immune responses of hybrid yellow catfish (pelteobagrus fulvidraco × P. vachelli) juveniles.

This study investigated the effect of heat stress on the physiological parameters, oxidation resistance ability and immune responses in juvenile hybrid yellow catfish. Heat stress group exposed to 35°C and control to 28°C. Blood and liver were sampled at different hours' post-exposure. Results showed that red blood cell (RBC), white blood cell (WBC) counts, Hemoglobin (HGB) levels and hematocrit (HCT) values increased significantly (P < 0.05) post-exposure to heat stress. This indicates the increase of cell metabolism. Serum alanine aminotransferase (ALT) and aspartate transaminase (AST) activities, total cholesterol (TC), total protein (TP), triglyceride (TG) and glucose increased significantly (P < 0.05) indicating the need to cope with stress and cell damage. Liver TC, TG, COR hormone, C3 complement increased significantly from 24 to 96h. Heat stress mostly affects the hepatic antioxidant and immune resistance functions, resulting in increments of cortisol levels, lysozyme, superoxide dismutase (SOD), and catalase (CAT) enzyme activities. The increase of Malondialdehyde (MDA), alkaline phosphatase (AKP) indicate stimulation of the immune responses to protect the liver cells from damage. The decrease in Liver TP indicated liver impairment. Decrease in Glycogen content from 6 to 96h indicated mobilization of more metabolites to cope with increased energy demand. Interestingly, results showed that heat stress trigged costly responses in the experimental fish like accelerated metabolism and deplete energy reserves, which could indirectly affect ability of fish to set up efficient long term defense responses against stress. These results provide insight into prevention and management of stress in juvenile hybrid yellow catfish.

Severe Metacercarial Invasion of the Gills of Farmed Clariid Catfish Juveniles

Severe Metacercarial Invasion of the Gills of Farmed Clariid Catfish Juveniles

Effects of Fe-DTPA on Health and Welfare of the African Catfish Clarias gariepinus (Burchell, 1822)

Fingerlings (0.23 g) and juveniles (267.04 g) of African catfish (Clarias gariepinus) were reared for 32 days under experimental aquarium conditions and were exposed to either 0.75 mg/L or 3.0 mg/L diethylenetriaminepentaacetic acid-iron(II) (Fe-DTPA) and 3.0 mg/L or 12.0 mg/L Fe-DTPA in the water, respectively. These treatment groups were compared to a control group without additional Fe-DTPA. The growth, mortality, ethological indicators (activity, agonistic interactions, air-breathing), leukocyte distribution, histopathological changes in liver and gills, and genetic biomarkers were evaluated for each group. While the growth, mortality, and behavior were not significantly different between the groups, the lymphocyte count in the fish’s blood increased significantly in all groups during the course of the experiment, but independently from the treatments. A similar trend (p &gt; 0.05) was observed in monocytes. The number of granulocytes decreased significantly, but independently from the treatments. These changes indicated the possibility of an ongoing immune response in the fish from all treatments that might be caused by the increasing aggressive behavior of the fish. However, the Fe-DTPA treatments did not cause a notable suppression or enhancement of the immune reactions. Fe3+ accumulations in liver tissues were detected at the tested concentrations, and further changes occurred in the cells of the gills. Gene-expression biochips were used to simultaneously quantify the transcript levels of 34 genes associated with iron metabolism and stress physiology in head kidney samples. The obtained gene-expression profiles did not reveal any significant differences across either the different treatments or the time points. The results indicate that Fe-DTPA supplementation in the tested concentrations can be considered relatively harmless for the health and welfare of African catfish.

Growth performance and blood figures of African catfish (Clarias sp.) fed with marine fungal fermented feed

This study examined the impact of marine fungal fermented feed at various concentrations on the growth and blood profiles of African catfish Clarias sp.. Catfish with an average body weight of 0.74 ± 0.01 g were raised in an aquarium that measured 30 cm x 45 cm x 30 cm and contained 25 L of water. The feed was not fermented in this study (control), and the feed was fermented with marine fungi at various concentrations (using 0.5%, 1%, 2%, and 4% extract marine fungi). At 8:00 am, 12:00 pm, and 16:00 pm, fish were fed three times a day until they were completely satisfied. The results showed that feeding juvenile catfish marine fungal fermented diet resulted in significantly higher growth performance. The larger final biomass, faster growth, and lower feed conversion ratio were used to examine this. The generation of red blood cells in fish fed with fermented diets was higher and better than the control treatment, according to the results of the blood profile of catfish (P 0.05).

Effect of Probiotic (Saccharomyces Cerevisiae) Based Diet on Growth, Survivial Rate and Carcass Composition of African Catfish Juveniles

Effect of Probiotic (Saccharomyces Cerevisiae) Based Diet on Growth, Survivial Rate and Carcass Composition of African Catfish Juveniles

Effectiveness of adding monosodium glutamate to an artificial feed on the growth and survival of Asian Redtail Catfish (Hemibagrus nemurus)

The problems in Asian Redtail Catfish farming are low growth and survival rate. Therefore, it is necessary to provide adequate feed to increase the production. One of these important nutrients is glutamine which can be obtained in the form of monosodium glutamate (MSG). This study aimed to evaluate the effectiveness of adding MSG to feed on the growth and survival rate of Asian Redtail Catfish. Five experimental diets with graded levels of MSG were used, i.e. P0 as the control (0.0 g kg-1 feed), P1 (0.5 g kg-1 feed), P2 (1.0 g kg-1 feed), P3 (1.5 g kg-1 feed), and P4 (2.0 g kg-1 feed) with three replications. Twenty Asian Redtail Catfish juveniles were randomly distributed into aquarium (10 L in capacity) and kept in conditions without changing water. The fish were fed three times a day to apparent satiation at 08.00 AM, 01.00 PM, and 06.00 PM. The fish on MSG supplemented diets had higher final body weight, specific growth rate, and feed conversion ratio. Furthermore, MSG treatment groups had increased feed intake and feed efficiency, but there were no significant differences in final mean body weight. In conclusion, the current study showed that adding MSG to the diet could enhance growth and survival of Asian Redtail Catfish.

Effects of dietary tryptophan on cannibalism, survival and growth of Wallago attu (Bloch &amp; Schneider, 1801) juveniles

This study aims to evaluate the effects of supplemented commercial diets with tryptophan (TRP) on plasma serotonin, cannibalism, survival rate, and growth of Wallago attu (helicopter catfish). After one week of acclimation, 3,200 juveniles of helicopter catfish (BW = 2.5 ± 0.27 g, total length = 5.6 ± 0.43 cm) were randomly assigned for the experiment in fifteen plastic tanks (200 L). The experiment was conducted with five treatments (CT – 0 g TRP/kg – control group, T1 – 5 g TRP/kg, T2 – 10 g TRP/kg, T3 – 20 g TRP/kg, and T4 – 40 g TRP/kg) in a completely randomized design with three replications for four weeks. The results from the enzyme-linked immunosorbent assay reveal that TRP-supplemented diets effectively increased the serotonin level (5-HT) in the plasma of the catfish. The serotonin level increased with the dose of TRP added to the feed. Furthermore, a higher TRP level significantly decreased cannibalism and improved the final survival of the fish. However, the fish’s growth rate among treatments T1, T2, T3, and T4 was not significantly different, but there was a statistical difference between the experimental treatments and the CT treatment. The findings of this study suggest that TRP could be supplemented at a dose of 20 g·kg–1 to the feed to reduce cannibalism and improve the final survival of helicopter catfish.