Growth Of Nile Tilapia Research Articles

Dose Optimization of 17 α-Methyltestosterone to Maximize Sex Reversal of Nile Tilapia (Oreochromis Niloticus)

The study investigated the optimum dose of 17 α-methyltestosterone (17α–MT) for maximum sex reversal and growth performance of Nile tilapia (Oreochromis niloticus). Using a completely randomized design, three treatments (Control, T-1, T-2, and T-3) in triplicates were set up. The control group diet was devoid of 17α–MT. The remaining three groups, T-1, T-2, and T-3, were fed feed that contained 30, 60, and 100 mg kg-1 of 17α–MT, respectively. Fry of three days old were stocked at a rate of 100 per tank. They were fed with experimental diet for 28 days. After the hormone treatment and 90 days of rearing the highest survival rate was found in the control group. Gonadal squashing of O. niloticus showed different sex ratios for different treatments. The control group showed a normal sex ratio of 48.33% males and 51.67% females. The experimental group T-3 showed the highest percentage of males (98.33%) followed by T-2 (93.33%) and T-1 (76.66%). After 90 days of rearing, although the study found the highest mean length (82.12±1.5 mm), weight (26.74±0.08 g) and SGR (9.17±0.05%) in the treatment T2, these growth performance parameters did not differ significantly with the result of treatment T3. The Nile tilapia's sex ratio has been found to be more affected by a higher dose, or 100 mg 17α–MT kg-1 of feed. With the increase of hormone inclusion level, sex reversal percentage increases. Higher doses of 17α–MT have also a positive impact on Nile tilapia growth performance. Growth increases with the increasing 17α–MT level up to 60 mg in the diet of O. niloticus. Based on the study, the recommended dose for producing maximum mono-sex male tilapia in commercial hatcheries may be 100 mg 17α–MT kg-1 feed.
 Vol. 9, No. 3, December 2022: 377-384

Vitamin E supplementation in diet ameliorates growth of Nile tilapia by upgrading muscle health

Vitamin E (VE), an important lipid-soluble antioxidant, has great influence on growth and maintenance in animal. The effects of VE supplemented diet on growth and feed usage in Nile tilapia (Oreochromis niloticus) was investigated in this study. Three formulated diets containing VE (0, 50 and 100 mg/kg) were fed to Nile tilapia (3.56 ± 0.16 g) in glass aquaria maintaining three replicate groups for 56 days (8 weeks). Survival, growth performance including weight gain, percent weight gain, and specific growth rate (WG, % WG, and SGR), and feed utilization comprising protein efficiency ratio and feed conversion ratio (PER and FCR) were calculated. Hemato-biochemical indices including hemoglobin level (Hb), white blood cell (WBC), red blood cell (RBC) and glucose level were analyzed. In addition, muscle morphology was examined after completion of the experiment. At the end of the trial, WG, %WG, SGR, FCR and PER increased significantly which had dietary VE supplimentation. However, no distinct changes were observed in Hb level, RBC count, WBC count and glucose level among these different dietary groups. Dietary VE treatments significantly upgraded the muscle fiber diameter and lowered the intra-muscle gap. Moreover, quantity of hyperplastic muscle fiber as well as nucleus also significantly enhanced by VE. Morphological structure of muscle characterized by a huge proportion of hyperplastic muscle that may be supposed to contribute the enhanced growth of Nile tilapia receiving VE supplemented diet. Therefore these results suggested that VE incorporation into the feed can be effective to improve the feed efficiency and maximize the growth of O. niloticus.

Utilization of rotifers as natural feed in the rearing of saline nile tilapia (Oreochromis niloticus) larvae

After the yolk sac of fish larvae is absorbed, they will utilize external food sources such as natural phytoplankton and zooplankton. Specifically, one of the zooplankton species used is the small-sized rotifer Brachionus sp., which matches the mouth opening of the larvae. The purpose of the experiment was to examine the effects of providing live rotifer in combination with artificial feed on the survival rate and growth of Nile tilapia (Oreochromis niloticus) larvae in high salinity conditions. The Nile tilapia larvae used in the experiment were the offspring of Red Nifi strain breeders raised in freshwater and still containing yolk sacs. Feeding commenced after the yolk sacs were absorbed, and the salinity was gradually increased to 25-30 ppt. The larvae were fed with rotifers for seven days (P-1), 14 days (P-2), and then continued with another type of artificial feed. There was also a control group that only received artificial feed without rotifers. The stocking density of the fish larvae was 25 individuals per liter, and the total water volume used was 15 liters. The rotifer dose was maintained at 10-20 individuals per milliliter of water per day during the 4-week rearing period. The results showed that providing rotifers in water salinity between 10-15 ppt during the first seven days resulted in a survival rate of > 80%, whereas the control group achieved > 90% survival. However, the survival rate of the larvae started to decline from the second seven-day period with the increase in salinity between 15-25 ppt, and it continued to decrease to < 60% until the fourth week for all treatments.

The effect of Spirulina (Arthrospira platensis) as a microbial diatory feed supplement for juvenile of Nile Tilapia (Oreochromis niloticus)

Tilapia is the second most farmed fish in tropical and sub-tropical countries worldwide. This study investigated the effect of replacing fish meal by Spirulina platensis (groups fed with 5%, 10% and 15% Spirulina) on the growth of Nile tilapia O. niloticus juveniles. Intestinal microbiota of tilapia has been studied by MiSeq Illumina sequencing. No significant differences (P > 0.05) were observed for the protein, carbohydrate and lipids of fish fed with control food and different concentrations of spirulina. However, the Margalef species richness of the intestinal bacteria of tilapia fed with spirulina was significantly higher (P < 0.05) compared to the control samples. Evenness was significantly higher (P < 0.05) for tilapia fed with food substituted with the highest concentration of spirulina. Also, few potentially probiotic genera, like Bacillus and Actinomycetes were detected in the gut of the experimented Tilapia. On the other hand, the highest percent of potentially pathogenic genera was recorded for the genera Pseudomonas and Corynebacterium. In most cases, the highest abundances of potentially pathogenic species were found in control samples. As manipulation of the feed was shown to improve Tilapia microbiota, which could lead to further improvements in aquaculture production.

Effect of Black Soldier Fly (Hermetia illucens) Larvae Feed Supplement on Length-Weight Relationship of Nile Tilapia (Oreochromis niloticus)

One of the main challenges in the aquaculture sector is the high cost of fishmeal, which accounts for about 70 percent of production costs. The black soldier fly (BSF) larvae meal could be an alternative because of its high protein and essential fatty acids contents that are important for fish to grow and develop normally. An analysis was carried out to examine the effect of various feeding strategies on the growth and performance of Nile tilapia (Oreochromis niloticus). Five diets with equal nitrogen content were enriched with BSF larvae meal at different proportions (0%, 25%, 50%, 75%, and 100%). The meal with 0% BSF was used as a control. The length and weight of the fish were collected biweekly, while mortality data were collected daily. The study assessed the length and weight relationship of the fish using the parameter \'b\'(regression coefficient). From this research, \'b\' was found to range from 3.230 to 3.635, indicating isometric growth patterns. The well-being of the experimental fish was also evaluated through the condition factor \'K,\' which ranged from 0.907 to 1.002, suggesting that all the fish were in good health. We, therefore, conclude that substituting the conventional fish means with black soldier fly larvae appears to be possible and impacts fish growth normally.

Effect of Dietary Inclusion of Papaya (Carica Papaya) Seed and Pulp Meal on the Growth of Nile Tilapia (oreochromis niloticus) Reared in Concrete Tank in Togo

A study on the growth performance of Oreochromis niloticus was carried out, from June to August 2020, with diets incorporating papaya seeds and pulp meal (Carica papaya). Therefore, 600 mono-sex fry male of Nile tilapia (average weight ≈ 2 g) were distributed in 12 concrete tanks (0.6 m3) at a density of 50 fishes per tank. They were fed four isoprotein diets (32% PB) in triplicate including a commercial feed (CF), a local feed containing 30% palm kernel meal cooked in water for one hour (LF) to which 5g of seeds powder (SF) was added or 4g of pulp powder (PF) of papaya/kg of diet, for 70 days. Then, after a 2-day fasting period, 5 fish from each batch were dissected in order to assess growth through the study of digestive transit. At the end of this trial, encouraging results were obtained. Survival rate was generally in the order of 90% for all batches. The best zootechnical performances were observed in the fish fed with SF and PF (FCR = 1.78 and 1.99; PER = 1.72 and 1.51; SGR = 3.48 and 3.56 %/d). In addition, feed transit was slower in all intestinal compartments of fish of these batches. Incorporating papaya products is a promising option for the growth of O. niloticus.

Phytase Supplementation under Commercially Intensive Rearing Conditions: Impacts on Nile Tilapia Growth Performance and Nutrient Digestibility

This study evaluated the effects of phytase supplementation on growth performance and apparent digestibility of Nile tilapia (Oreochromis niloticus) in a commercial fish farm setting. Nile tilapia (6300 male, 57.48 ± 1.04 g) were randomly stocked into 42 floating cages. The experimental design was completely randomized, comprising six treatments and seven replications. Fish were fed five phosphorus deficient plant-based diets with graded levels of phytase supplementation (0, 500, 1000, 1500, 2000 UF kg-1) and an additional diet containing phosphorus supplementation to meet the requirement of this fish species (positive control). After 97 days of feeding, growth performance data were collected and 900 fish (500 ± 10 g) were relocated to 6 floating cages for the digestibility assessment. Quadratic polynomial regression analysis indicated 1537.5 and 1593.2 UF kg-1 as the optimum dietary levels for daily weight gain and feed conversion rate, respectively. Including 2000 UF kg-1 resulted in the higher dry matter, crude protein, energy, and ash apparent digestibility coefficient values. Therefore, phytase supplementation from 1500 to 2000 UF kg-1 is recommended to enhance growth performance and nutrient bioavailability of Nile tilapia reared according to industry practices.

Age and Growth of Nile Tilapia, Oreochromis niloticus (Linnaeus, 1758), From Koka Reservoir, Ethiopia

The age and growth rate of the fish species must be known since they are essential input variables that compose stock assessment models to assess the stock status and estimate the exploitable potential of the stock. The age and growth of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), in Koka Reservoir, Ethiopia, were studied based on 981 sagittal otoliths collected monthly from December 2017 to November 2018. Otoliths were grounded and examined under a stereoscopic microscope at 10–40× magnification for macrozones analysis using a reflected light source. The age of the fish was determined based on the number of translucent zones counted in the otoliths of O. niloticus by considering the time of translucent zone formation and median hatch date. Seasonal records on the macrozones at the edge of otoliths and relative marginal increments suggested that two translucent macrozones associated with biannuli were formed each year, one from January to February, and another one from June to July. The observed ages of O. niloticus from Koka Reservoir ranged from 1 to 6.5 years, and the most dominant classes were 2 and 3 years. Growth was determined using the von Bertalanffy growth function. The von Bertalanffy growth parameters (sexes combined) were; asymptotic length (total length), L∞ = 35.6 cm, growth rate constant, K = 0.37 year-1, theoretical age at zero-length, t0 = -0.42 years and the growth performance length, φ’ = 2.67. It could be concluded that the growth of O. niloticus in Koka Reservoir is within the range mentioned in Ethiopian lakes.

Dietary supplementation with Moringa oleifera leaves extract reduces the impacts of sub-lethal fipronil in Nile tilapia, Oreochromis niloticus

This study assessed the restorative dietary effects of Moringa oleifera (MO) leaves extract against the negative impacts of sub-lethal fipronil (FIP) toxicity in Nile tilapia. To achieve this purpose, the growth, body composition, haemato-biochemical measurements, serum immunity, and antioxidant condition of Nile tilapia have been examined. Fish were arranged into 6 experimental groups in quadruplicates. Three groups were fed on diets supplemented with 0.0 (reference group), 1.0 (MO1), and 2.0 (MO2) g kg−1 of MO leaf extract. The other three groups were fed on the same MO levels and concomitantly subjected to a sub-lethal FIP concentration (4.2 µg L−1 for 3 h only per day) and defined as FIP, FIP + MO1, and FIP + MO2. The experiment lasted for 8 weeks. Results unveiled that growth parameters were significantly decreased alongside an increased feed conversion ratio in the FIP-intoxicated group. The moisture and crude protein (%) were decreased significantly together with a significant increase of the crude lipids (%) in the fish body of the FIP group. Sub-lethal FIP toxicity induced hypochromic anemia, leukopenia, hypoproteinemia, hypoalbuminemia, hypoglobulinemia, and hepato-renal failure (increased urea and creatinine concentrations, as well as ALT and AST enzymes). Exposure to sub-lethal FIP also induced (a) immunosuppression manifested by a decline in total IgM, complement C3, and lysozyme activities, (b) enzymatic antioxidant misbalance manifested by decreases in SOD and CAT activities, and (c) oxidative stress (declined T-AOC and elevated of MDA concentrations). On the other side, dietary supplementation with MO leaf extract in FIP + MO1 and FIP + MO2 groups noticeably modulated the aforementioned parameters. Therefore, we can conclude that dietary MO could reduce sub-lethal FIP toxicity in Nile tilapia with a possible recommendation for regular prophylaxis supplementation in Nile tilapia diets.

The effect of different dose on biological performance and its correlation with growth of nile tilapia (Oreochromis niloticus)

This study was to find out the biological effects of different feed dose and their relationship to the growth of tilapia. Fingerlings of Oreochromis niloticus, with an average initial weight range of 4.42 - 4.44 g were randomly distributed into three treatments and replicated 3 times using concrete fish container.The treatments were three feed doses namely: 5% (A); 8% (B); adlibitum (C) of 32% crude protein floating pellet feed, in crumble-shaped. The effect of different dose on growth and its correlation were determined. A one-way analysis of variance (ANOVA) was used to determine of initial, final and absolut weight, Average body weight (ABW) and Average daily growth (ADG). Feed conversion ratio, survival rate and biomass were also counted. Polynomial analysis was further used to prove whether the amount of feed provided is effective for fish growth. Temperature, pH, disolleved oxygen and ammnonia were test. The results noted that biological performance parameters were not signifanctly different (p ≥ 0.05) between treatments. Polynomial results showed for its growth tilapia fish using 98-99% of the feed given. The results of water quality parameters indicated an optimal range value to growth of nile tilapia.

QUANTITATIVE AND QUALITATIVE EFFECTS OF 010K - LACTOBACILLUS PARACASEI AND THE "ECOPROBIOTIC" PROBIOTIC PREPARATION ON THE GROWTH AND INTESTINAL MICROFLORA OF FISH

The most important result of fish rearing in closed water systems is to achieve the highest possible growth rate while creating optimal aqueous environment factors. The growth of fish is influenced by many factors, including probiotics in artificial diets. In this sense, functional food supplements, including pro-, pre- and synbiotics, are gaining increasing attention as an environmentally sound strategy to improve fish health. Probiotics, participating in digestive processes, affect the metabolism of the host organism, promote protein synthesis and increase the degree of their assimilation. The aim of this study was to investigate the effects of the 010K - Lactobacillus paracasei strain that isolated from Kazakhstan koumiss and the "Ecoprobiotic" probiotic preparation on the growth of intestinal microflora in Nile tilapia. The study outcomes displayed that live weight of fish in the experimental groups (010K - Lactobacillus paracasei and probiotic preparation "Ecoprobiotic") was higher than in the control group. Moreover, fish fed with the "Ecoprobiotic " probiotic and 010K - Lactobacillus paracasei strain had a significantly higher number of yeast cells compared to the control group. In summary, the 010K - Lactobacillus paracasei and probiotic preparation "Ecoprobiotic" may be a promising candidate for the improving growth and intestinal microbiota of Nile tilapia.

Effects of dietary reishi mushroom (Ganoderma lucidum) on the growth performance of Nile tilapia, Oreochromis niloticus juveniles

In aquaculture, several medicinal mushrooms have been successfully used as prebiotics, with attractive growth-stimulant, immune-modulatory, and antioxidant functions for several finfish species. Herein, we designed a 90-day continuous feeding trial to assess the impacts of supplementing diets with a reishi mushroom (Ganoderma lucidum) powder on growth parameters and expression responses of some genes that correlated with growth, digestion, and lipid metabolism in Nile tilapia. Four isonitrogenous and isocaloric diets have been formulated by incorporating reishi mushroom powder (RMP) at varying inclusion doses as 0.0, 5.0, 10.0, and 20.0 g/kg to form four RMP-based diets defined as RMP0 (reference diet), RMP5, RMP10, and RMP20, respectively. After the end of the 90-day feeding experimental trial, mean final weight (Wt90), weight gain percentage (WG%), feed conversion rate (FCR), and specific growth rate (SGR) have been improved significantly in fish groups fed RMP-based diets with regard to those fed the reference diet. The highest Wt90, WG%, and SGR values and the lowest FCR values were present in RMP10 group in comparison with the other groups. However, no significant variations were found in these parameters between RMP5 and RMP20 groups. The fish survival rate (SR %) was the same between all test groups. At the molecular levels, the expression levels of growth-correlated genes such as growth hormone, growth hormone receptor, and insulin growth factor 1 have been increased in the RMP10 group. Similarly, the mRNA transcripts of digestion-correlated genes such as pepsinogen, chymotrypsinogen, trypsinogen, and cholecystokinin genes, and lipid metabolism-related gene (lipoprotein lipase) have been up-regulated significantly in the RMP10 group. Of interest, the second-order polynomial regression performed on Wt90, WG%, SGR, and FCR values against the dietary RMP levels showed that the optimum supplementation level of RMP in diets of Nile tilapia was 12.50 g RMP / kg diet. Our findings propose the noticeable prebiotic effects of RMP for improving aquafeed's functionality and tilapia culture's sustainability.

Dietary inclusion of pine pollen alters sex ratio and promotes growth of Nile tilapia (Oreochromis niloticus, L. 1758)

The potential of pine pollen (PP) to masculinize sexually undifferentiated Nile tilapia was evaluated by feeding graded levels of PP (0.08–3.20 g kg-1 basal diet) to triplicate groups of three-day-old Nile tilapia for 28 days. Masculinization and associated differences in growth were compared to fish individuals fed the same basal diet with no PP (CT; negative control) and with 0.06 g 17α-methyltestosterone (MT) kg-1 basal diet (positive control). Both PP and MT treatments significantly skewed the expected 50:50 (male: female) ratio towards more male individuals. Notably, MT and 1.28 g PP kg-1 of diet produced a significantly high proportion of males (89.2 ± 2.2% and 80.0 ± 2.9% respectively), compared to 50.8 ± 2.2% in the CT treatment (P < 0.001). Except for 0.08 g PP kg-1 of diet, the final body weight and specific growth rate of individuals fed PP and MT-supplemented feeds were significantly higher than fish from the CT group. Although 1.28 g PP kg-1 diet produced the highest masculinization, the fish fed 3.20 g PP kg-1 diet had the highest final weight (14.73 ± 0.54 g), suggesting the presence of growth enhancers in PP. Similarly, a superior feed conversion ratio was recorded in both PP and MT-treated groups compared to the CT treatment (P = 0.024). However, the condition factor and survival rate of fish in all groups did not differ significantly. Overall, 1.28 g PP kg-1 diet was potent in sex inversion and promoted the growth of Nile tilapia, making PP a promising alternative to MT in the production of all-male stock.

Plankton Composition and Abundance in Semi Intensive Aquaculture Pond and their Preference by Nile tilapia

Plankton is major food item for Nile tilapia and their availability is one of the most important factors affecting its growth performance in an extensive and semi-intensive pond-based culture systems. Thus, this study aimed to examine plankton composition, abundance, and feeding preference by Nile tilapia reared under a semi-intensive pond-based production system. The experiment was carried out using ponds (10mx15mx1.7m size) fertilized with chicken manure at the rate of 100g/m2/week. Nile tilapia with 7.8g average body weight was stocked at a density of 2 fish/m2. Examination of plankton from both pond water and stomach samples of fish was done using qualitative assessment methods. The results showed that a total of 20 phytoplankton groups were identified following standard identification key. These include four types of Blue-green algae (Cyanophyceae), seven types of Green algae (Chlorophyceae), six Diatoms (Bacillariophyceae), one type of Dinophyceae, and two types of Euglenophyceae. Among the phytoplankton groups, Chlorophyceae was the dominant group with 56% followed by Bacillariophyceae (23%), Cyanophyceae (17%), and Euglenophyceae (3%) while the least was Dinophyceae (1%). The most frequently observed algal genus was Scenedesmus. In addition, three Zooplankton groups namely Copepods (43%), Rotifers (31%) and Cladocerans (26%) were also identified. The result indicated that, the most preferred planktonic groups used by Nile tilapia was green algae, particularly Chlorophyceae followed by Copepoda and Rotifers. The level of chlorophyll `a` was 62.3±2.0 μg/l concentration. The different water quality parameters together with the availability of different plankton were optimal for the growth of Nile tilapia which resulted in a 0.45 specific growth rate. In conclusion, Nile tilapia exhibit preference for green algae, blue-green algae from phytoplankton, and Copepods from zooplankton groups than other groups of plankton.

Growth, Feed Efficiency, Hemato-Biochemical Indices, and Flesh Quality of Adult Nile Tilapia, Oreochromis niloticus, Fed a Diet Supplemented with Nano-Selenium

Growth, Feed Efficiency, Hemato-Biochemical Indices, and Flesh Quality of Adult Nile Tilapia, Oreochromis niloticus, Fed a Diet Supplemented with Nano-Selenium

Dietary Supplementation with Prebiotic Chitooligosaccharides Enhances the Growth Performance, Innate Immunity and Disease Resistance of Nile Tilapia (Oreochromis niloticus)

Prebiotics acting as immunosaccharides exhibit immunomodulatory functions to improve the immune defense of the host against infectious diseases. The purpose of the present study was to investigate the effects of dietary chitooligosaccharide (COS) supplementation on the growth, innate immunity and disease resistance of Nile tilapia (Oreochromis niloticus) fed a diet containing 0.4%, 0.8% and 1.2% COSs for 8 weeks. The results showed significant increases in weight gain (WG), feed efficiency (FE) and specific growth rate (SGR) in COS-supplemented fish compared to fish in the control group. The fish exhibited a significant decrease in cumulative mortality in fish fed 0.8% and 1.2% COS when challenged with Streptococcus iniae. The immune parameters, including phagocytotic activity (PA), respiratory burst (RB) activity, and superoxide dismutase (SOD) activities of the head kidney and serum lysozyme, as well as the expression of TNF-α, IL-1β and IL-8, were revealed in 0.8% and 1.2% COS-supplemented fish. These results demonstrated that COS could be used as a prebiotic and that dietary supplementation with 0.8% COS could improve growth performance and innate immunity against pathogen infections in Nile tilapia.

Interactive effects of dietary phosphorus and microbial phytase on growth performance, intestinal morphometry, and welfare of Nile tilapia (Oreochromis niloticus) fed on low-fishmeal diets

One of the industries with the fastest growth rates in the world is aquaculture. However, as fish meal (FM), the most expensive component of aquafeeds, is increasingly replaced with plant protein, the amount of phosphorus (P) in fish diets decreases as a result of plant proteins' high phytate content, which chelates P. Inorganic P is a dietary supplement that increases fish development and feed utilization, but its high inclusion in aquafeeds causes eutrophication due to environmental contamination. Consuming dietary phytase can make more P available, which lowers the amount of inorganic P in fish diets. The present study assessed the effects of replacing inorganic P in Nile tilapia (O. niloticus) diets with a hybrid microbial phytase (HMPhyt) derived from bacteria hybrid (Buttiauxella gaviniae, Yersinia mollaretti, and Hafnia sp.) on growth and welfare. Fish (1.50 ± 0.16 g) were divided into 18,100-L tanks with 20 fish each, and they were fed one of six low FM diets that were both isonitrogenous (300 g/kg) and isocalorific (17 kJ/g). The control diet had no P or HMPhyt supplements (0P + 0HMPhyt), the second diet contained 0.2 g/kg (1000FTU/kg) HMPhyt only (0P + HMPhyt), the third diet contained 100% P (13.0 g/kg) only (100P + 0HMPhyt), and the fourth to the six diets contained 75% (9.8 g/kg) P (75P + HMPhyt), 50% (6.5 g/kg) P (50P + HMPhyt), or 25% (3.3 g/kg) P (25P + HMPhyt). Fish were fed the experimental diets three times each day for 56 days, until they appeared satisfied. In comparison to the control diet (0P + HMPhyt), the results reveal that dietary phytase and/or inorganic P significantly increased Nile tilapia growth indices and feed intake (P < 0.05) than the control group. In contrast, there were no differences in the feed conversion ratio or the percentage of fish that survived among the various fish groups (P > 0.05). In addition, fish fed on P and/or HMPhyt containing diets had significantly greater counts of red and white blood cells, packed cell volume, and hemoglobin, as well as higher intestinal villi width/height, and absorption area compared to the control group. In contrast, higher levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and malondialdehyde were found in fish fed the control diet (0P + HMPhyt), while higher levels of superoxide dismutase, catalase, lysozyme, and respiratory burst activity were found in fish fed the inorganic P and/or HMPhyt based diets As a result, dietary HMPhyt (1000 FTU/kg) can totally substitute inorganic P in Nile tilapia diets without having any negative impacts on the fish's welfare or growth.

Pectoral Fin Morphometry of Nile Tilapia (Oreochromis niloticus) Cultivated in Different Aerator and Filter

The anomaly of the pectoral fin is caused by an inappropriate amount of oxygen and ammonia within the water, which is expected to be resolved by the combination usage of an aerator and filter. This study aimed to analyze the combination usage of an aerator and filter with different amounts toward the growth of Nile tilapia’s pectoral fin. This study used a 2×2 factorial completely randomized design consisting of 4 treatments (ANF, AANF, AF, and AAF) with 6 replications. The measurement variable of the pectoral fin includes length, width, weight, and the ratio of the pectoral fin’s length with the total size of the fish. The measurement was analyzed using two way-ANOVA and continued with the LSD test. The results of the combination usage of the aerator and filter revealed a significant effect (P0.05) on the pectoral fin length, pectoral fin width, pectoral fin weight, and ratio of pectoral fin length to total body length. The research’s conclusion was the combination of usage aerator and filter had a positive impact on the growth of Nile tilapia’s pectoral fin. The study’s novelty is the combination usage of an aerator and filter with a different number to promote the growth of the cell within the pectoral fin of Nile tilapia. This research would benefit people through the discovery of the combination usage of an aerator and filter to improve the growth of Nile tilapia’s pectoral fin.

Transcription factor Sox3 is required for oogenesis in the teleost fish Nile tilapia

Oogenesis is a complex developmental process responsible for the production of eggs from oogonia in fish and other animals. However, transcriptional regulation underlying oogenesis is not fully understood. In the present study, we demonstrated in the teleost fish Nile tilapia that the Sox transcription factor family member Sox3 was involved in regulating oocyte growth during oogenesis. Fluorescence in situ hybridization showed that Sox3 expression was enriched in growing oocytes of ovary but could not be detected in testes. CRISPR/Cas9-mediated homozygous mutation in the Sox3 gene disrupted oocyte growth. Further analysis revealed that Sox3 mutation caused a decrease in the contents of neutral lipids in oocytes and estradiol-17 beta (E2) production. RNA-seq-based transcriptome profiling and RT-qPCR analysis in ovaries demonstrated that the expression levels of genes involved in E2 production, lipid accumulation, and yolk formation were significantly downregulated following Sox3 mutation. Altogether, our findings indicate that Sox3 is required for oocyte growth in Nile tilapia and provides insights into transcriptional regulation underlying oogenesis in teleost fish.

Effects of different carbon sources on water quality, biofloc quality, and the productivity of Nile tilapia reared in biofloc-based ponds

Abstract The present study evaluated the effects of different carbohydrates materials used as carbon sources on water quality, biofloc quality, and growth and productive performance of Nile tilapia (Oreochromis niloticus) reared in biofloc (BFT)-based cement ponds (25 m x 10 m x 1.2 m; with 250 m3 volume). Nile tilapia fingerlings (44.9±1.9 g) were distributed into nine ponds at a density of 40 fish per 1 m3 (10000 fish/pond) to represent three treatments in triplicates. The control ponds received no carbon source addition; meanwhile sugarcane molasses (MO) and wheat flour (WF) were added to ponds. A commercial diet (30% crude protein) was offered to fish in each pond at levels of 3% and 2% of live body weight of fish in the control and BFT-based ponds, respectively, for 12 weeks. The amounts of feed were divided equally to three equal portions and offered to fish at 9:00, 13:00, and 17:00 h. The control ponds’ water was replaced by 50% every day with new water; meanwhile in MO and WF ponds, water loss via evaporation or leakage was compensated to reach the 1.0 m depth only. The pH value as well as unionized ammonia and nitrite levels, in the present study, were significantly lower, meanwhile nitrate and total suspended solids levels were significantly higher in MO and WF-treated ponds than the control one. The WF treatment resulted in significantly larger biofloc volume and higher total bacterial count compared to the MO treatment. The highest growth and production indices of Nile tilapia were observed in the BFT-based treatments as compared with the control group; particularly at the WF treatment followed by the MO treatment. In conclusion, the WF addition to cement fishponds is a more beneficial carbonaceous source for the efficient water quality, biofloc biomass, and growth and productivity of Nile tilapia reared in BFT-based system.