Juvenile Catfish Research Articles

Effects of Teifairia occidentalis and Vernonia amygdalina Supplements on Growth Performance of Clarias gariepinus Fingerlings

This study examined the growth-enhancing potential of Telfaira occidentalis and Vernonia amygdalina leaf powder in Clarias gariepinus culture. The experiment was conducted at Tiddo Fish Farm Makurdi. One thousand juvenile catfish were obtained from the farm’s hatchery and allocated to five treatment groups identified as Control (0% supplement inclusion), T1 (10% fluted pumpkin leaf powder inclusion), T2 (20% fluted pumpkin leaf powder inclusion), T3 (10% bitter leaf powder inclusion) and T4 (20% bitter leaf powder inclusion). The fish were fed thrice daily for 8 weeks and water changed daily, to determine growth parameters of fish and physico-chemical parameters of water. Results obtained show that after the treatment period, Mean Weight gain and Specific Growth Rate was not significantly different (p>0.05). However, Specific Growth Rate and Percentage Survival rate differed significantly (p<0.05), highest (7.9% and 100%) in T3 respectively. Water quality parameters such as pH, Dissolve Oxygen and Temperature were within the recommended range and not significantly affected. Both plant species feed inclusions were utilized by fish, which was observed to facilitate the growth and survival of the fish species, with high percentage survival. In conclusion, T3 inclusion levels showed better growth performance.

EVALUATING GROWTH AND NUTRIENT COMPOSITION OF AFRICAN CATFISH UNDER DIFFERENT SALINITIES

An investigation was carried out to explore the effect of salinity on the growth and flesh quality of African catfish (Clarias gariepinus), a significant species in global aquaculture. Fifty juvenile catfish of weight 24.25±0.4g were collected from the Chenab River in Pakistan and acclimatized in controlled aquaculture conditions at different salinity levels NaCl (T1; 0, T2; 2, T3; 4; T4; 6, and T5; 8 ppt) over 60 days. Growth performance indicators, including final weights, weight gain, growth rate, and feed conversion ratio (FCR), were measured. The statistical result indicated that the fish in lower salinity environments (0-2 ppt) exhibited significant (p < 0.05) final weights, weight gain, and growth rates, with performance declining significantly as salinity increased. The best FCR 1.2±0.01 was indicated at 0 ppt, while the highest salinity (8 ppt) was revealed in the FCR 1.7±0.04. Proximate composition analysis indicated that crude protein and moisture content elevated with salinity while crude fat and ash content decreased. These results suggest that C. gariepinus thrives in slightly brackish conditions, with optimal growth at low salinity levels. However, higher salinities adversely impact physiological health and growth performance.

Changes in the Histopathology of the Visceral organ of African catfish (Clarias Gariepinus, Burchell 1822) fed various herbal plant additives

Histopathological studies have been established as effectual and sensitive tools for monitoring fish health. This study evaluated histopathological changes in African catfish fed with herbal additives. African Catfish juveniles (210) with an average weight of 117.3g and average length of 26.7cm were randomized into ten sub-groups and fed diets containing Allium sativum, Chromoleana odorata, and Talinum triangulare; 0.5%, 1.0%, and 3% concentrations, each of the herbal plants and 0% (control) for 42 days and changes in the visceral organs were investigated. Fish were sacrificed on the 43rd day and their visceral organs were collected and fixed in bouin’s fluid for 24h, washed with 10% formalin, and dehydrated through a graded series of ethanol. Collected organs were embedded in paraffin, sectioned at 4-5um thickness, stained with Hematoxylin and Eosin, and scanned with a light microscope. The intestine, gill, liver, and kidney of control and fish fed with 0.5% Allium sativum showed no damage. However, effects ranging from slight lamellae hyperplasia to noticeable lamellae hyperplasia were detected in the gills of the fish nurtured with 3.0% inclusion rates of C. odorata and T. triangulare. Epithelial necrosis and atrophy of tubules in the kidney at a 3.0 % inclusion rate of C. odorata were detected. In conclusion, Allium sativum, Chromoleana odorata, and Talinum triangulare could be included at lower inclusion rates of 0.5 – 1% into Clarias gariepinus feed for prime performance.

Effects of dietary inclusion of Chaya leaf (Cnidoscolus chayamansa) meal as feed additives in the diets of African catfish (Clarias gariepinus, Burchell, 1822) Juveniles

Effects of dietary inclusion of Chaya leaf (Cnidoscolus chayamansa) meal as feed additives in the diets of African catfish (Clarias gariepinus, Burchell, 1822) Juveniles

Isolation and characterization of a strain Clostridium butyricum B3 from the intestine of Pelteobagrus fulvidraco and its potential probiotic roles

The use of host-associated probiotics in aquaculture have been limited due to difficulties in their isolation from the host gastrointestinal tract and validation of their biological function. Here, anaerobic Clostridium butyricum strain B3 was isolated for the first time from the intestines of yellow catfish (Pelteobagrus fulvidraco). Alignment of 16 S rDNA sequences revealed 99 % identify between strain B3 and wild-type C. butyricum. C. butyricum B3 was found to tolerate a wide range of temperature (up to 80 °C) and pH (1 to 13) levels. In vitro microbial growth experiments revealed that C. butyricum B3 produced acetic acid (890.00 ± 23.00 mg/L) and butyric acid (672.67 ± 51.67 mg/L) highly productively within 24 h. Further in vitro characterization findings also suggested that C. butyricum B3 is sensitive to several antibiotics, including ampicillin and chloramphenicol, and potently inhibits the growth of pathogenic bacteria such as Aeromonas hydrophila. In a feeding experiments, 30 days of dietary supplementation with 3.0 × 107 to 109 CFU/g B3 significantly increased the specific growth rates of yellow catfish juveniles by more than 61.5 %. Activities of trypsin, α-amylase and lipase were significantly enhanced in group fed with 3.0 × 107 B3 compared to the control group (P < 0.05). Furthermore, ACP activity was significantly increased by more than 25.0 %, whereas malondialdehyde content significantly decreased by at least 38.5 % in all B3 feeding groups (P < 0.05). In addition, hepatocyte density increased, and goblet cells in the intestinal epithelial cells expanded. Meanwhile, C. butyricum B3 feeding significantly activated genes (such as grhpr and enpp2) involved in lipid metabolism and proliferator-activated receptor signaling pathway, increased bacterial diversity, and reduced the bacterial richness of the gut microbiota (P < 0.05). In conclusion, dietary inclusion of 3.0 × 107 CFU/g of C. butyricum B3 enhanced the growth performance, immune response, and lipid metabolism of P. fulvidraco.

Assessment of dietary yeast-based additives for cultured catfish and tilapia health.

Channel catfish (Ictalurus punctatus) and Nile tilapia (Oreochromis niloticus) are two aquaculture species of great importance. Intensive production is often hindered by poor growth performance and disease mortality. The aim of this study was to evaluate the potential of a commercial fermented yeast product, DVAQUA, on channel catfish and Nile tilapia growth performance metrics and disease resistance. Channel catfish and Nile tilapia were fed practical diets supplemented with 0%, 0.1% or 0.4% of DVAQUA over approximately 2-month feeding periods in recirculation aquaculture systems. To assess the potential of the postbiotic against common aquaculture pathogens, juvenile catfish were subsequently challenged by immersion with Edwardsiella ictaluri S97-773 or virulent Aeromonas hydrophila ML09-119. Nile tilapia juveniles were challenged by injection with Streptococcus iniae ARS-98-60. Serum lysozyme activity, blood chemistry and growth metrics were measured at the end of the feeding period, but no differences were observed across the different metrics, except for survival. For the pathogen challenges, there were no differences in endpoint mortality for channel catfish with either pathogen (p > .05). In contrast, Nile tilapia survivability to S. iniae infection increased proportionally to the inclusion of DVAQUA (p = .005). Changes to sera lysozyme activity were also noted in the tilapia trial, with a reduction of activity in the fish fed the 0.4% DVAQUA diet compared to the control diet (p = .031). Expression profiles of proinflammatory genes and antibodies were also found to be modulated in channel catfish fed the postbiotic, indicating some degree of protective response. These results suggest that this postbiotic may be beneficial in protecting Nile tilapia against S. iniae infection by influencing immune parameters and additional research is needed to evaluate the potential of this DVAQUA for improving catfish health and disease control.

Protium heptaphyllum essential oil from the fruit as a sedative and anesthetic in Rhamdia quelen: influence in cardiac frequency, biochemical, and oxidative parameters.

This study aimed to evaluate the effects of Protium heptaphyllum fruit essential oil (PHEO) on the physiology of silver catfish (Rhamdia quelen) during anesthesia and recovery, through studying echocardiograms, oxidative status, and metabolic parameters. Three experiments were performed: (1) 50 silver catfish juveniles were submitted to anesthesia and recovery tests with 300, 400, 500, 600, and 700mg L-1 of PHEO. (2) Echocardiogram analysis was performed in anesthetized and non-anesthetized fish. (3) Biochemical parameters were evaluated at 0, 30, 60, and 120min of recovery after being anesthetized for 3min with 600mg L-1 PHEO. Times to sedation and deep anesthesia were reduced with PHEO increasing concentrations. The echocardiogram showed a higher cardiac rate in anesthetized fish. Plasma glucose levels increased in control fish through recovery time, but anesthetized fish showed lower levels than controls at 120min of recovery. Metabolic parameters such as plasma and hepatic glucose did not show changes considering the recovery time of up to 120min. Hepatic glycogen, lactate, and triglycerides reduced their levels over recovery times. Fish anesthetized enhanced superoxide dismutase activity and thiobarbituric acid reactive substances levels but decreased reduced glutathione (GSH) levels at 30min compared to controls. After 60min, GSH values were significantly higher in anesthetized fish than in controls. These results suggest that PHEO at 600mg L-1 is an effective anesthetic for the rapid handling of silver catfish, providing stable metabolic parameters and enhanced antioxidant responses during recovery. Echocardiogram analysis confirms the anesthetic effect, supporting PHEO as a viable and efficient option for fish anesthesia in aquaculture. The use of PHEO in aquaculture can enhance fish welfare by reducing stress during handling and transportation, potentially leading to improved growth, health, and survival rates.

Dietary inclusion of insect oil: Impact on growth, nutrient utilisation, lipid metabolism, antioxidant and immune-related responses in European catfish (Silurus glanis L)

In this study, we investigated the black soldier fly (Hermetia illucens) larvae oil (IO) as replacement of fish oil and vegetable oil in the diets of European catfish. The formulated diets included a control diet (CTR) containing fish oil (FO) and rapeseed oil (RO), and two experimental diets replacing FO and RO, with 50% and 100% IO, respectively. The nutritional trial comprising 630 European catfish juveniles (average initial body weight: 28.1 ± 0.17 g) randomly distributed into triplicated dietary groups (CTR, IO50, and IO100) was conducted for 8 weeks in a recirculation aquaculture system. The study was focused to evaluate the impact of IO on fish growth and nutrient utilisation, lipid metabolism, antioxidant, and immune-related responses in juvenile fish. Results obtained indicated that all the diets promoted adequate fish growth and feed utilisation, with no significant differences in these parameters between the dietary fish groups. It appears that the diets did not impact the activity of digestive enzymes, but a decrease in the apparent digestibility coefficients was observed. Significant differences were observed in tissue fatty acid (FA) composition. The significantly higher levels of whole-body total saturated fatty acids and arachidonic acid in fish fed IO-based diets relative to those fed CTR diet were accompanied by significantly lower levels of whole-body monounsaturated fatty acids and n-3 polyunsaturated fatty acids (n-3 PUFA). However, some deviations in this trend were observed in the liver highlighting the sparing effect for long chain polyunsaturated fatty acids (LC-PUFAs). Gene expression analysis showed a significant upregulation of genes encoding lipoprotein lipase (lpl), carnitine palmitoyl transferase (cpt1a), and hepatocyte nuclear factor 4 alpha (hnf4α) in the livers of fish fed the IO100 diet. Among the five immune-related genes examined in the spleen, only interferon regulatory factor 1 was significantly upregulated in fish fed IO50 relative to the CTR. These results indicated upregulated metabolic activities in fish fed the IO100 diet probably due to a higher level of dietary medium chain saturated fatty acids (MCSFA) and a lower level of LC-PUFA, creating the need for fish to oxidise more MCSFA and to deposit more LC-PUFA in the tissues in order to maintain fatty acid balance.

Digestibility of Cockroach (Periplaneta americana) Insect Meal Diet By African Catfish (Clarias gariepinus) Juvenile and Its Effects on growth Performance

The use of Cockroach (Periplaneta americana) meal was studied to ascertain its digestibility and effect on growth performance of Clarias gariepinus. A 40% protein basal and test diets using fish and cockroach meal respectively with inert biomarker at 70:30% were fed for 42 days to Clarias gariepinus of average weight 29.22±0.18g. Catfish response to diets in terms of growth parameters revealed the following for reference diet fed and basal diet fed fish: weight gain (52.59g vs. 36.31g); specific growth rate (2.46%/g/day vs. 1.91%/g/day); feed conversion ratio (1.71 vs. 2.13); and percentage weight gain (181.44% vs. 123.35%). Apparent digestibility values of test diet were higher significantly (P&lt;0.05) than basal diet. Digestibility coefficient in reference diet fish and basal diet fish showed that: protein (88.48% vs 87.01%); dry matter (87.35% vs. 86.82%); energy (86.88% vs. 85.48%); and fat (39.67% vs. 27.75%). African catfish responded positively to CIM diet with improved growth performance up to 30% inclusion level. Apparent digestibility of the CIM diet was superior to the fishmeal reference diet.

Exploring the nutritional value of corn fermented protein as a replacement for soybean meal in diets for juvenile channel catfish (Ictalurus punctatus): Impacts on production performance, intestinal health, and disease resistance

The use of corn fermented protein (CFP) can be a promising alternative ingredient to replace soybean meal (SBM) in aquafeeds, because of its attractive price and constant supply. In this study, the apparent digestibility of CFP was evaluated with channel catfish (Ictalurus punctatus), followed by a comparative feeding trial in which dehulled, solvent extracted SBM in the control diet was incrementally replaced with graded levels of CFP. A slight but significantly higher apparent protein digestibility coefficient was observed for SBM (91%) compared to CFP (89%). However, phosphorus and lipid were twice as available from CFP than SBM. A 60-day feeding trial was conducted, testing the gradual replacement of SBM by CFP on an equalnitrogen basis at 0, 25, 50, 75, and 100%. Channel catfish juveniles (∼11.6 g) were stocked in 30 aquaria (30 fish/ 110-L tank; n = 6) operating as a recirculating system and offered the experimental diets to apparent satiation twice daily. No differences were observed for hepatosomatic index, survival, or serum superoxide dismutase and lysozyme activities. Also, no treatment effects were observed for whole-body protein, ash, and protein conversion efficiency. However, weight gain, feed efficiency, intraperitoneal fat, and whole-body lipid were significantly affected by the dietary treatments with CFP able to replace up to 40 to 58% of the SBM in the diet while providing similar fish performance and body composition as fish fed the control diet. Digesta samples from the posterior segment of the intestine were subjected to DNA extraction, followed by 16S rRNA gene (V3-V4 region) sequencing to profile the intestinal microbiota. A higher relative abundance of Aeromonas spp. was observed for fish fed the control diet. The remaining fish from the feeding trial were challenged with Edwardsiella ictaluri, and cumulative survival was monitored for 21 days. Survival after the bacterial challenge gradually increased as the inclusion levels of CFP increased in the diets, with the 100% replacement treatment being significantly different from the control diet. In conclusion, CFP is a promising alternative plant protein ingredient with high protein and phosphorus digestibility, and it can replace up to 40 to 58% of the SBM in feed formulations for juvenile channel catfish based on weight gain and feed efficiency while potentially increasing disease resistance against E. ictaluri.

Improved growth, body composition, and fatty acid composition in striped catfish juveniles, Pangasianodon hypophthalmus, fed with diets containing different oil sources

AbstractStriped catfish are one of the main aquaculture species in Asia. However, the low level of omega‐3 fatty acids in its body makes this species less attractive compared with marine fish. This study aimed to investigate the effect of different oils on growth performance, body composition, and fatty acids in striped catfish juveniles. A basal diet (T0) was formulated to contain no oil, while four other diets (T1, T2, T3, and T4) were supplemented at 4% with different oils, including salmon oil (SALO), soybean oil (SBO), linseed oil (LSO), and rapeseed oil (RSO). Catfish juveniles with initial body weight (23–24 g/fish) were randomly stocked in 500‐L fiberglass tanks, divided into five treatments, three replicates for each, and fed the experimental diets for 60 days. Results from this study revealed that fish fed the LSO‐supplemented diet had significantly (p &lt; 0.05) improved whole body omega‐3 (alpha‐linoleic acid, 18:3n3) fatty acid levels (7.86%), total n‐3 fatty acids (9.12%), and higher growth than those fed the other diets. In conclusion, the findings suggest that linseed oil can be used to improve growth, omega‐3 fatty acid, C18:3–3 (ALA), and total n‐3 PUFA deposition in the whole body of striped catfish juveniles.

Haematology in Juveniles of African Catfish (Clarias gariepinus) Exposed to Primextra Gold® (Atrazine) Herbicide

The widespread increase of pesticides application in crops frequently leads to the contamination of the fresh water ecosystem. One of the most commonly used pesticides in Nigeria is Primextra Gold® (atrazine) herbicide. The aim of this study is to evaluate the toxicity of Primextra Gold® (atrazine) on the juveniles of the African catfish, Clarias gariepinus. The toxicity was carried out using 120 healthy fish that were divided into six treatments (control inclusive) with each treatment having ten fish and the setup was replicated. The fish were exposed to 0.00 (control), 0.15, 0.29, 0.44, 0.59 and 0.74mg/L concentrations of Primextra Gold® (atrazine) for two weeks. During the exposure period, physicochemical parameters were determined. After two weeks of the experiment, blood samples were collected for heamatology using standard methods. Data obtained were subjected to ANOVA at P&lt;0.05using Minitab 17. Results of the physico-chemical parameters of water exposed to concentrations showed that there was a significant decrease (P&lt;0.05) in the amount of dissolved oxygen with increase in concentrations of the herbicide while pH, total dissolved solids (TDS) and electrical conductivity increased. Temperature showed no significant difference (P˃0.05). Haematological parameters reduced significantly (P&lt;0.05) in amount of PCV, Hb and RBC with increase in concentrations. Meanwhile WBC increased significantly (P&lt;0.05) with increase in concentration. A haematological change observed during the exposure is an indication of anaemia, leukocytosis, and haemoglobinaemia. The study revealed that Primextra Gold® (atrazine) was moderately toxic to Clarias gariepinus juveniles and affected the haematology as well as Physicochemical parameters of the exposed water. These results show that the contamination of water by pesticides either directly or indirectly could be lethal to fish or may reduce fish productivity. Elevated concentrations of undesirable chemicals in edible fish tissue can affect the health of humans eating these fishes.

Dietary β‐Mannanase Affects the Growth, Antioxidant, and Immunes Responses of African Catfish, Clarias gariepinus, and Its Challenge Against Aeromonas hydrophila Infection

One of the most farmed fishes is the African catfish, Clarias gariepinus. Its production has increased by 20% annually on average during the last 20 years, but the occurrence of fish diseases, especially bacterial such as Aeromonas hydrophila infections, is hindering its activities. Also, the incorporation of plant‐derived substances in aquafeeds is limited since they frequently contain different antinutritional factors, like nonstarch polysaccharides (NSPs). However, supplementing fish diets with β‐mannanase could increase growth, antioxidants, and immunity. Despite the advantage of β‐mannanase, its effects on growth, digestive enzymes, antioxidants, and immunity in African catfish need to be elucidated. This study examined the effects of dietary β‐mannanase on the growth performance, liver enzymes, antioxidant profiles, immunity, and protection of African catfish, C. gariepinus, against A. hydrophila infection. Five isonitrogenous diets were prepared to have 400 g/kg crude protein and supplemented with β‐mannanase at 0, 1500, 3000, 4500, or 6000 thermostable endo, 1,4‐β‐mannanase units (TMUs)/kg diet and fed to 300 juveniles of the African catfish, C. gariepinus (mean weight 12.1 ± 0.1 g) for 12 weeks. Then, 10 fish from each tank received an intraperitoneal injection of 0.1 mL of A. hydrophila (5.0 × 105 CFU/mL) and observed for 14 days. Results showed dietary β‐mannanase levels considerably improved growth performance but did not affect fish survival. Also, amylase, protease, and lipase levels were significantly promoted in the fish fed with β‐mannanase‐fortified diets than the control group (p &lt; 0.05). Enhanced gut villi and intestinal absorption areas, haematlogical profiles, and liver enzymes but reduced gut viscosity were observed in fish‐fed β‐mannanase‐fortified diets (p &lt; 0.05). In a dose‐dependent order, including β‐mannanase in the meals of African catfish raised the levels of glutathione (GSH), glutathione peroxidase (GPx), superoxide dismutase (SOD), glutathione‐S‐transferase (GST), and glutamate cysteine ligase (GCL) activities and decreased the malondialdehyde (MDA) values in African catfish (p &lt; 0.05). Also, fish immunity was greatly (p &lt; 0.05) enhanced due to supplementation of the diet with β‐mannanase. In addition, fish‐fed diets comprising 6000 TMU β‐mannanase/kg diet showed the lowest rates of fish mortality (7.5%) (p &lt; 0.05). Therefore, feeding African catfish, Clarias gariepinus, β‐mannanase enhanced growth performance, increased activity of digestive enzymes, gut morphology, enhanced generation of short‐chain fatty acids, digesta potential of hydrogen (pH), and improved antioxidant profiles and immunity at the optimum dose of 5800 TMU/kg diet. Additionally, β‐mannanase protected African catfish against A. hydrophila infection.

The influence of turmeric supplementation in feed on the growth performance of Asian Redtail Catfish (Hemibagrus nemurus)

Asian redtail catfish farming faces challenges with low seed production, necessitating improved feeding strategies to boost production. Antioxidants, such as those found in turmeric, are considered crucial feed ingredients. This research investigated the impact of turmeric-enriched feed on the growth performance of Asian redtail catfish. Five experimental treatments were formulated with varying turmeric concentrations: P1: 0.0 g kg-1 feed, P2: 0.5 g kg-1 feed, P3: 1.0 g kg-1 feed, P4: 1.5 g kg-1 feed, P5: 2.0 g kg-1 feed; each treatment had three replications. 20 juveniles of Asian redtail catfish were reared in 10-liter aquariums. The study duration was 55 days. Fish were fed to satiation three times a day (8:00 AM, 1:00 PM, 6:00 PM). Turmeric-supplemented diets resulted in increased final body weight, greater absolute length, higher specific growth rate, enhanced feed intake, and improved feed conversion ratio. Meanwhile no significant differences were observed in feed efficiency and survival rate. The study demonstrates that incorporating turmeric into the feed can effectively promote growth in Asian redtail catfish. These findings suggest that turmeric supplementation could be a valuable strategy for improving production in Asian redtail catfish culture.

Lethal Toxicity of Aqueous Extract of Sodom Apple (Calotropis procera) on African Catfish (Clarias gariepinus) (Burchell, 1822) Juveniles

The experiment was performed to check the lethal toxicity of aqueous extract of Calotropis procera on Clarias gariepinus juveniles. A range finding test was done and the concentrations for the definitive tests were determined. A total of 150 African catfish juveniles of average weight 9.37±0.08g were randomly selected and distributed into four treatments in triplicates of 20mg/L, 40mg/l, 60mg/L, 80mg/L concentrations and a control (0.00) using a static bioassay test over a period of 96 hours. Behavioral responses observed during exposure of the fish to lethal concentrations included erratic swimming, air gulping, haemorrhage, loss of equilibrium and sudden death. All data obtained were summarised using descriptive statistics for the mortality, water quality parameters, growth performance and nutrient utilization. While one-way analysis of variance (ANOVA) was used to assess differences in means among the concentrations and Duncan multiple range tests was used to separate the means, where there was a difference. Physico-chemical water parameters and haematological parameters showed various significant difference among the treatments (P&lt; 0.05). C. procera at higher concentrations of 40mg/L and above was highly toxic to fish, which led to erratic behavior and mortality.

Iron supplementation in the diets of hybrid catfish (Ictalurus punctatus × I. furcatus) juveniles affected haematocrit levels and potentially decreased disease resistance to Edwardsiella ictaluri.

To prevent catfish idiopathic anaemia, diets fortified with iron have been adopted as a regular practice on commercial catfish farms to promote erythropoiesis. However, the effects of prolonged exposure of excess dietary iron on production performance and disease resistance for hybrid catfish (Ictalurus punctatus × I. furcatus) remains unknown. Four experimental diets were supplemented with ferrous monosulphate to provide 0, 500, 1000, and 1500 mg of iron per kg of diet. Groups of 16 hybrid catfish juveniles (~22.4 g) were stocked in each of 20, 110-L aquaria (n = 5), and experimental diets were offered to the fish to apparent satiation for 12 weeks. At the end of the study, production performance, survival, condition indices, as well as protein and iron retention were unaffected by the dietary treatments. Blood haematocrit and the iron concentration in the whole-body presented a linear increase with the increasing the dietary iron. The remaining fish from the feeding trial was challenged with Edwardsiella ictaluri. Mortality was mainly observed for the dietary groups treated with iron supplemented diets. The results for this study suggest that iron supplementation beyond the required levels does affect the blood production, and it may increase their susceptibility to E. ictaluri infection.

Some Physiological Parameters of African Catfish, Clarias gariepinus (Burchell, 1822) Juveniles fed Composite Insect Meal and Phyto-Additives in Cage Culture System

A 70 days experiment was conducted to examine the effect of fishmeal substitution with defatted African palm weevil larvae supplemented with phyto-additives on the growth performance and nutrient utilization of Clarias gariepinus juveniles. Seven diets were formulated containing 45% crude protein: control diet was formulated using fishmeal as the principal protein source, three individual diets were prepared using 17% each of fish meal and defatted African palm weevil larvae supplemented with Telfairia occidentalis, Corchorus olitorious and Cymbopogon citratus as phyto-additives. Another three individual diets were prepared using 17% each of fish meal and defatted African palm weevil larvae supplemented with a mixture of Telfaria occidentalis and Corchorus olitorious, Telfairia occidentalis and Cymbopogon citratus, and Corchorus olitorious and Cymbopogon citratus as phyto-additives making it a total of seven diets. A total of 450 juveniles of African catfish (Clarias gariepinus) was used for the experiment and distributed into 21 baskets embedded in a pond each containing 20(7.50±0.00-7.53±0.00 g/fish) fish. At the end of the feeding trial, the mean weight gain was significantly different (P&gt;0.05) across the fish fed experimental diets. The fish fed with African palm weevil and Telfairia occidentalis as phyto-additives recorded the highest mean weight gain(95.66±25.64) percentage weight gain(91.77±2.14) compared to the other groups. The nutrient utilization indices such as feed conversion ratio, feed efficiency ratio were found to be better in fish fed African palm weevil compared with the CONTROL group. A significantly higher whole-body protein was recorded in fish fed African palm weevil and phyto-additives. From this study, it was concluded that processed African palm weevil larvae with phyto-additives especially Telfairia occidentalis can effectively replace fishmeal in the diet of Clarias gariepinus juveniles.

Supplementation of Chlorella vulgaris meal in diet for growth performance of striped catfish juvenile Pangasianodon hypophthalmus

The culture of striped catfish (Pangasianodon hypophthalmus) is overgrowing and facing the problem of relatively high feed prices. The feed prices affect feed grade; the cheaper the feed price, the lower the quality. This low feed quality may improve its quality by supplementing Chlorella vulgaris. Therefore, this study aimed to determine the level of supplementation of C. vulgaris meal in the feed that produces the best growth performance in striped catfish juveniles. A completely randomized design with three treatments and three replications was used in this experiment. The treatments were various levels of C. vulgaris, namely 0%, 1.5%, and 3%. C. vulgaris meal was added to the commercial feed (26-28% protein) according to the treatment with the coating method. The test feed was fed to striped catfish juveniles (6.66 ± 0.04 g in average weight) reared in an aquarium containing 55 L of water at a density of 20 juveniles, at satiation in the morning, afternoon, and evening for 50 days of the rearing period. Survival rate and hepatosomatic indices of the striped catfish were not affected by various supplementation levels of C. vulgaris meal (P&gt;0.05), but the values of feed consumption, specific growth rate, feed conversion, and protein efficiency ratio of the striped catfish (P&lt;0.05). Supplementation of 3.5% C. vulgaris meal in feed resulted in the best growth performance for striped catfish.

Effect of three commercial feeds on the growth performance of Hybrid Catfish (Heteroclarias) juveniles

The growth of aquaculture depends on good quality feed which has led to the importation of commercial feeds into the country. However, these imported feeds are usually not affordable by the average Nigerian fish farmer. To solve this problem different locally produced commercial fish feeds have also been introduced to the Nigerian market giving rise to many brands of fish feed. This study seeks to determine the effect of an imported commercial feed (feed A) and two locally produced commercial feeds (feed B and C) on growth and survival of Hybrid Catfish (Heteroclarias) juveniles. A total of one hundred and thirty-five (135) Hybrid Catfish (Heteroclarias) juveniles with mean weight 7.29±1.30g were fed the three commercial diets for 56 days (eight weeks). Fifteen juveniles were batched weighed and stocked in each 60-litre capacity circular plastic tanks. A triplicate trial was maintained for each commercial feed, giving nine tanks in all and 45 fishes per feed. Water quality parameters were within standard limits. Temperature was between 25.3-25.6℃, pH was 6.05-6.16.and dissolved oxygen was between 2.3- 2.45mg/l, 25.3-25.6℃, respectively. Fish fed imported commercial feed (feed A) and locally produced commercial feed (feed B) showed significant difference (P&lt;0.05) in final weight and mean weight gain when compared with fishes fed locally produced commercial feed (feed C). The specific growth rate, food conversion ratio and survival rate did not show significant difference (P≥0.05) in all the three treatments. Fish fed imported commercial feed (feed A) had the highest mean weight gain followed by locally produced commercial feed (feed B) and locally produced commercial feed (feed C) which had the least. The estimated cost for producing 1kilogramme of fish for feed A was N560.48 while feed B and C was N506.20 and N666.51 respectively. In terms of feed conversion ratio, feed intake, cost of feed and value of fish produced, locally produced commercial feed (feed B) gave the lowest cost of producing a kilogramme of fish. Therefore, locally produced commercial feed (feed B) can be used for Heteroclarias production in plastic tanks.&#x0D; &#x0D; &#x0D; &#x0D; &#x0D; La croissance de l’aquaculture dépend d’aliments de bonne qualité, ce qui a conduit à l'importation d’aliments commerciaux dans le pays. Cependant, ces aliments importés ne sont généralement pas abordables pour le pisciculteur nigérian moyen. Pour résoudre ce problème, différents aliments commerciaux pour poissons produits localement ont également été introduits sur le marché nigérian, donnant naissance à de nombreuses marques d'aliments pour poissons. Cette étude vise à déterminer l'effet d'un aliment commercial importé (aliment A) et de deux aliments commerciaux produits localement (aliment B et C) sur la croissance et la survie des juvéniles de poisson-chat hybride (Heteroclarias). Au total, cent trente-cinq (135) juvéniles de poissons-chats hybrides (Heteroclarias) d'un poids moyen de 7,29 ± 1,30 g ont été nourris avec les trois régimes commerciaux pendant 56 jours (huit semaines). Quinze juvéniles ont été pesés et stockés dans des réservoirs circulaires en plastique d'une capacité de 60 litres chacun. Un essai en triple a été maintenu pour chaque aliment commercial, donnant neuf réservoirs en tout et 45 poissons par aliment. Les paramètres de qualité de l'eau étaient dans les limites standard. La température était comprise entre 25,3 et 25,6 ℃, le pH était de 6,05 à 6,16. et l'oxygène dissous était entre 2,3 et 2,45 mg/l, 25,3 et 25,6 ℃, respectivement. Les poissons nourris avec des aliments commerciaux importés (aliment A) et des aliments commerciaux produits localement (aliment B) ont montré une différence significative (P&lt;0,05) dans le poids final et le gain depoids moyen par rapport aux poissons nourris avec des aliments commerciaux produits localement (aliment C). Le taux de croissance spécifique, le taux de conversion alimentaire et le taux de survie n'ont pas montré de différence significative (P≥0,05) dans les trois traitements. Les poissons nourris avec des aliments commerciaux importés (aliments A) avaient le gain de poids moyen le plus élevé, suivis des aliments commerciaux produits localement (aliments B) et des aliments commerciaux produits localement (aliments C) qui en avaient le moins. Le coût estimé pour produire 1 kilogramme de poisson pour l'aliment A était de 560,48 N tandis que les aliments B et C étaient respectivement de 506,20 N et 666,51 N. En termes de taux de conversion alimentaire, de consommation d'aliments, de coût des aliments et de valeur des poissons produits, les aliments commerciaux produits localement (aliments B) ont donné le coût le plus bas de production d'un kilogramme de poisson. Par conséquent, les aliments commerciaux produits localement (aliments B) peuvent être utilisés pour la production d’Heteroclarias dans des réservoirs en plastique.

Striped catfish (Pangasianodon hypophthalmus) exploit food sources across anaerobic decomposition- and primary photosynthetic production-based food chains

Dietary information from aquatic organisms is instrumental in predicting biological interactions and understanding ecosystem functionality. In freshwater habitats, generalist fish species can access a diverse array of food sources from multiple food chains. These may include primary photosynthetic production and detritus derived from both oxic and anoxic decomposition. However, the exploitation of anoxic decomposition products by fish remains insufficiently explored. This study examines feeding habits of striped catfish (Pangasianodon hypophthalmus) at both adult and juvenile stages within a tropical reservoir, using stable carbon, nitrogen, and sulfur isotope ratios (δ13C, δ15N, and δ34S, respectively) and fatty acid (FA) analyses. The adult catfish exhibited higher δ15N values compared to primary consumers that feed on primary photosynthetic producers, which suggests ingestion of food sources originating from primary photosynthetic production-based food chains. On the other hand, juvenile catfish demonstrated lower δ15N values than primary consumers, correlating with low δ34S value and large proportions of bacterial FA but contained small proportions of polyunsaturated FA. This implies that juveniles utilize food sources from both anoxic decomposition and primary photosynthetic production-based food chains. Our results indicate that food chains based on anoxic decomposition can indeed contribute to the dietary sources of tropical fish species.