ABSTRACT. Commercial farming of tilapia species has been spread to many countries worldwide to meet the need for animal protein at an affordable price, which has led tilapias to invade natural areas. Consequently, tilapias have established wild populations, causing a great negative impact on native biodiversity. The Sonora River, located in northwest Mexico, has an approximate length of 400 km, and at least four native fish species inhabit it. Nevertheless, the Sonora River has been severely reduced and contaminated by open-pit mining. According to existing knowledge, the presence of tilapias is not reported in the Sonora River; hence, the present study is the first report of the presence of the Nile tilapia Oreochromis niloticus in a site near the town of Baviácora, Sonora, Mexico. The presence of this invasive species may represent a severe threat to the biotic component of this ecosystem, which is already affected by mining pollution.

Summary The effectiveness of collagen extracted from Nile Tilapia (Oreochromis niloticus) fish scale on the encapsulation of β-carotene was evaluated. Two encapsulations were performed by lyophilization: encapsulation with soy protein (EP) and encapsulation with collagen and soy protein (ECP) in 1:4 ratio. The samples were physiochemically characterized, their fluidity properties were evaluated, and mathematical and kinetic models were used to predict the stability of the encapsulated β-carotene stored at 35°C for eight weeks. Collagen extraction yield was 13.85 %, collagen had the following proximal composition: protein 47 %, ash 40 %, fat 9 % and moisture 7.9 %. Initially, ECP showed a higher retention rate (TR = 83.4 %) than EP (TR = 53.3 %), while after storage at 35 °C for eight weeks, β-carotene retention in ECP was 0.84%, while in EP reached only 0.48 %. ECP encapsulation efficiency (66.7 %) was better than that of EP (42.6 %). High cohesiveness and intermediate fluidity were found in EP and intermediate cohesiveness and intermediate fluidity in ECP. According to results, collagen from this source proved to be a functional material for encapsulating β-carotene.

Resumen Se evaluó la efectividad del colágeno extraído de la escama del pez Tilapia del Nilo (Oreochromis niloticus) en la encapsulación de β-caroteno. Se realizaron dos encapsulaciones por liofilización: encapsulación con proteína de soya (EP) y encapsulación con colágeno y proteína de soya (EPC) en proporción 1:4. Las muestras se caracterizaron fisicoquímicamente, se evaluaron sus propiedades de fluidez y se utilizaron modelos matemáticos y cinéticos para predecir la estabilidad del β-caroteno encapsulado almacenado a 35 °C durante ocho semanas. Se obtuvo un rendimiento de extracción de colágeno del 13.85 %, el colágeno tuvo la siguiente composición proximal: proteína 47 %, ceniza 40 %, grasa 9 % y humedad 7.9 %. Inicialmente, EPC mostró una mayor tasa de retención (TR = 83.4 %) que EP (TR = 53.3 %), mientras que después del almacenamiento a 35 °C durante ocho semanas, la retención de β-caroteno en EPC fue de 0.84 %, mientras que en EP alcanzó solo 0.48 %. La eficiencia de encapsulación de EPC (66.7 %) fue mejor que la de EP (42.6 %). Se encontró alta cohesividad y fluidez intermedia en EP y cohesividad intermedia y fluidez intermedia en EPC. Según los resultados, el colágeno de esta fuente demostró ser un material funcional para encapsular el β-caroteno.

ABSTRACT The effect of a partial substitute of fish meal by biofloc meal on the growth and survival of fry Nile tilapia Oreochromis niloticus was evaluated over nine weeks. Two biofloc meals were obtained by drying them in two processes: A) sun exposure and B) convection oven. A randomized design of eight isonitrogenous (40%) and isoenergetic (17 kJ g-1) diets was used, where 5, 10, 15, and 20% of the fish meal was substituted for the two biofloc meals. The nutritional study was conducted in a recirculating aquaculture system with Nile tilapia fry (initial weight: 0.64 ± 0.16 g). The survival range was similar in all treatments and higher than 97%. Tilapia fed with the treatments A5, A10, B5, and B10 of substitution of biofloc meal showed similar and significantly better final weight, individual weight gain, specific growth rate, and condition factor than A15, A20, B15, and B20 treatments; as well as efficiency of use of the feed: protein efficiency ratio, carcass nitrogen deposition, apparent nitrogen utilization, and apparent digestibility. Therefore, these results suggest that biofloc meal is possible in diets for tilapia, thus reducing the need for fishmeal as the main source of protein in the diet.

ABSTRACT In the commercial culture of Nile tilapia (Oreochromis niloticus), monosex, all-male populations obtained through steroid sex reversal is the most commercially used method to eliminate unwanted reproduction and increase final productive and economic yield. However, the rapid growth of Nile tilapia culture has led, in some regions, to an increase in infectious diseases and mortality in all stages of commercial culture. To reduce this, without the abuse of antibiotics or similar substances, feed additives are currently used in all stages, including the fry period, during the sex reversal process. The objective of this work was to evaluate the effect of synthetic steroid Fluoxymesterone (FM) at various concentrations in combination with a commercial Blend of additives (BA) on the percentage of males, growth, and survival of Nile tilapia fry. Five treatments (FM20, FM5+BA, FM10+BA, FM20+BA, and BA+FM20) and a control group were evaluated. Treatments differ in the order in which the commercial blend (2 g) was added and the FM concentration (5, 10, and 20 mg). The feeding trial lasted for 30 days using a sexually undifferentiated population of Nile tilapia. The results showed a decrease in the percentage of males in all treatments supplemented with the BA, compared to the FM20 treatment (containing 20 mg without BA). Growth and survival were positively affected by the inclusion of the BA in all treatments, showing higher values than those observed in the control group. Further studies are necessary to determine the FM-BA interaction.

ABSTRACT The effect of natural and synthetic aromatase enzyme inhibitors on growth, survival, and masculinization in Nile tilapia offspring was evaluated. Five flavonoids: chrysin (CRI), 7-hydroxyflavone (7-HF), apigenin (NA), naringenin (NAR), and 7-methoxyflavone (7-MF) at 1 000, 1 500, and 2 000 mg kg-1; a non-steroidal compound: letrozole (LT) at 50, 100, and 200 mg kg-1; and two synthetic steroids: exemestane (EXE) at 1 000, 1 500, and 2 000 mg kg-1, and 17 α-methyltestosterone (MT) at 60 mg kg-1 (C+), with a negative control free of compounds (C-). Each treatment was conducted in triplicate with n = 30 fish per replicate (0.012 ± 0.01 g) in cylindrical tanks (6 L) with continuous flow at 28°C. The 7-HF groups at 1 000 and 2 000 mg kg-1 showed significantly higher specific growth (16.08 ± 0.63% and 8.38 ± 2.11%, respectively). Survival was 100%, except for 7-HF 2,000 mg kg-1, NA 1,500 mg kg-1, 7-MF at 1 500 mg kg-1, and EXE at 1 500 and 2 000 mg kg-1, with 80 and 90%. The percentage of males in MT, EXE, and LT was 100%, but the flavonoid treatments varied, increasing from 57% males in C- to 71 to 86% for CRI 2 000, 7-HI 1 500, and all inclusion levels of 7-MET, NA, and NAR treatments. Further evaluation is expected to establish the concentration of natural inhibitors closer to 100% males.

RESUMEN Se evaluó el efecto de inhibidores naturales y sintéticos de la enzima aromatasa sobre el crecimiento, supervivencia y masculinización en crías de tilapia del Nilo. Cinco flavonoides: crisina (CRI), 7-hidroxiflavona (7-HF), apigenina (NA), naringenina (NAR) y 7-metoxiflavona (7-MF) a 1 000, 1 500 y 2 000 mg kg-1; un compuesto no esteroideo: letrozol (LT) a 50, 100 y 200 mg kg-1 y dos esteroides sintéticos: exemestano (EXE) a 1 000, 1 500 y 2 000 mg kg-1 y 17 α-metiltestosterona (MT) a 60 mg kg-1 (C+) y un control negativo libre de compuestos (C-). Cada tratamiento se realizó por triplicado con n = 30 peces por réplica (0.012 ± 0.01 g) en tanques cilíndricos (6 L) con flujo continuo a 28°C. Los grupos 7-HF a 1 000 y 2 000 mg kg-1 presentaron el crecimiento específico significativamente mayor (16.08 ± 0.63% y 8.38 ± 2.11%, respectivamente). La supervivencia fue de 100%, excepto: 7-HF 2000 mg kg-1, NA 1 500 mg kg-1, 7-MF a 1 500 mg kg-1 y EXE 1 500 y 2 000 mg kg-1, con 80 y 90%. El porcentaje de machos en MT, EXE y LT fue 100%, pero los tratamientos con flavonoides fueron muy variables, pero incrementando de un 57% de machos en el C-, de 71 a 86%, para CRI 2000, 7-HI 1 500, y todos los niveles de inclusión de los tratamientos 7-MET, NA y NAR. Se espera continuar la evaluación para establecer la concentración de inhibidores naturales que sea más cercana a 100% de machos.

ABSTRACT Antimicrobial peptides are small molecules that exhibit strong antagonistic activity against pathogenic microorganisms and are synthesized by a wide variety or organisms, including probiotic bacteria. The aim of the study was to identify peptides with antimicrobial activity in the Enterococcus faecium IP5-2a strain previously isolated from the intestinal tract of Nile tilapia (Oreochromis niloticus). Cellular and extracelullar proteins extraction was performed, followed by 1D SDS-PAGE gel electrophoresis and MALDI-TOF/TOF mass spectrometry. The results revealed peptides with antimicrobial activity, including P54 (SagA) protein, a bacteriocin-like protein and a lantibiotic. These proteins play an important role in the antagonistic capacity of the E. faecium IP52a strain, allowing it to be considered as a potential probiotic in the aquaculture industry.

RESUMEN Los péptidos antimicrobianos son moléculas pequeñas que poseen una fuerte actividad antagónica frente a microorganismo patógenos y son sintetizados por una amplia variedad de organismos, entre ellos, bacterias probióticas. El objetivo del estudio fue identificar péptidos con actividad antimicrobiana en la cepa Enterococcus faecium IP52a previamente aislada del tracto intestinal de tilapia del Nilo. Se realizó extracción de proteínas celulares y extracelulares, electroforesis en gel SDS-PAGE 1D y espectrometría de masas MALDI-TOF/TOF. Los resultados mostraron péptidos con actividad antimicrobiana, entre ellos la proteína P54 (SagA), una proteína similar a bacteriocina y un lantibiótico. Estas proteínas juegan un rol importante en la capacidad antagónica de la cepa E. faecium IP52a, permitiendo considerarla como un potencial probiótico en la industria acuícola.

Abstract The present study aimed to produce a monosex population of all male Nile tilapia (Oreochromis spp.) using 17α-methyl testosterone and common carp testes (as a source of natural androgen). Trial was conducted into two consecutive phases, the first was fry (4-5 days old)administration with negative control (without hormone) and positive control (with hormone) feed viz., MT1:60mg/kg, MT2:70mg/kg (17α-MT), carp testis CT1:70% and CT2:80% for 30 days to reverse the sex of male fish and the second phase was nursing the fingerlings for two months on control diet (32% Crude protein).Results revealed a significant growth rate (P<0.05) in the control group where final weight (4.8±0.34ab) and weight gained was recorded as 0.66±0.03ac. In proximate chemical composition of body meat, CT2 treatment showed maximum retention of crude protein, crude fat, and ash whereas dry matter showed maximum retention in MT2 and CT1 treatments. Morphological and histological examination revealed significant difference (p<0.05) in phenotypic males of Nile tilapia fed with the highest percent in MT-treated diet (MT2) of 95±0.58a while MT1, CT2 and CT1 had males of 85±6.0b, 70±5.0b and 65±6.5b, respectively. It was concluded that synthetic androgen (17αMT) was more effective for masculinization but natural androgen scan be an alternative method to produce male tilapia population in an environment-friendly manner as they are inexpensive, eco-friendly, and radially available. These results suggested that synthetic and natural androgen supplementation in the diet plays a significant role in improving growth performance and body composition. Oreochromis spp. spp 17αmethyl αmethyl 17α methyl α androgen. . androgen) phases 45 4 5 (4- oldadministration old administration without hormone viz viz. MT160mg/kg, MT160mgkg MTmgkg MT1 60mg/kg, 60mg kg MT mg MT1:60mg/kg MT270mg/kg MT270mgkg 70mg/kg 70mg 17αMT, 17αMT αMT , (17α-MT) CT170% CT170 CT 70% 70 CT1:70 CT280% CT280 80% 80 CT2:80 3 32% 32 (32 protein.Results proteinResults protein .Results Results P<0.05 P005 P 0 05 (P<0.05 4.8±0.34ab 48034ab ab 8 34ab (4.8±0.34ab 066003ac ac 66 03ac 0.66±0.03ac meat fat treatments p<0.05 p005 p (p<0.05 MTtreated treated (MT2 95058a 95 58a 8560b b 85 6 0b 85±6.0b 7050b 6565b 65 5b 65±6.5b respectively (17αMT environmentfriendly environment friendly inexpensive ecofriendly, ecofriendly eco friendly, eco-friendly available (4 MT160mg MT160mg/kg mgkg 60mgkg 60mg/kg MT270mg 70mgkg (17α-MT CT17 7 CT1:7 CT28 CT2:8 (3 P<0.0 P00 (P<0.0 p<0.0 p00 (p<0.0 (MT 9 ( MTmg CT1: CT2: P<0. P0 (P<0. p<0. p0 (p<0. P<0 (P<0 p<0 (p<0 P< (P< p< (p< (P (p

Resumo O presente estudo teve como objetivo produzir uma população monossexuada de todos os machos de tilápia do Nilo (Oreochromis spp.) usando 17α-metil testosterona e testículos de carpa comum como fonte de andrógeno natural. O ensaio foi conduzido em duas fases consecutivas, a primeira foi a administração de alevinos (4-5 dias) com controle negativo (sem hormônio) e controle positivo (com hormônio), viz., MT1:60mg/kg, MT2:70mg/kg (17α -MT), testículos de carpa CT1:70% e CT2:80% por 30 dias para inverter o sexo dos peixes machos e a segunda fase foi amamentar os alevinos por dois meses com dieta controle (32% de proteína bruta), e analisar a taxa de crescimento (p < 0,05) no grupo controle, em que o peso final (4,8 ± 0,34 ab) e o peso ganho foram registrados como 0,66 ± 0,03 ac. Na composição química aproximada da carne corporal, o tratamento CT2 mostrou retenção máxima de proteína bruta, gordura bruta e cinzas, enquanto a matéria seca apresentou retenção máxima nos tratamentos MT2 e CT1. O exame morfológico e histológico revelou diferença significativa (p < 0,05) nos machos fenotípicos de tilápia do Nilo alimentados com o maior percentual na dieta tratada com MT (MT2) de 95 ± 0,58a enquanto MT1, CT2 e CT1 tiveram machos de 85 ± 6,0b, 70 ± 5,0 e 65 ± 6,5b, respectivamente. Concluiu-se que o andrógeno sintético (17αMT) foi mais eficaz para a masculinização, entretanto os andrógenos naturais podem ser um método alternativo para produzir população de tilápias machos de maneira ecológica, pois são baratos, ecológicos e estão disponíveis radialmente. Esses resultados sugerem que a suplementação de andrógenos sintéticos e naturais na dieta desempenha um papel significativo na melhoria do desempenho do crescimento e da composição corporal. Oreochromis spp. spp 17αmetil αmetil 17α metil α natural consecutivas 45 4 5 (4- sem hormônio hormônio, , viz viz. MT160mg/kg, MT160mgkg MTmgkg MT1 60mg/kg, 60mg kg mg MT1:60mg/kg MT270mg/kg MT270mgkg 70mg/kg 70mg MT, -MT) CT170% CT170 CT 70% CT1:70 CT280% CT280 80% 80 CT2:80 3 32% 32 (32 bruta) p 0,05 005 0 05 4,8 48 8 (4, 034 34 0,3 ab 066 66 0,6 003 03 0,0 ac corporal cinzas (MT2 9 058a 58a 60b b 6 0b 6,0b 7 50 5, 65b 5b 6,5b respectivamente Concluiuse Concluiu se 17αMT αMT (17αMT masculinização ecológica baratos radialmente (4 MT160mg MT160mg/kg mgkg 60mgkg 60mg/kg MT270mg 70mgkg -MT CT17 CT1:7 CT28 CT2:8 (3 00 4, 0, 06 (MT ( MTmg CT1: CT2:

Resumo O estudo foi conduzido para avaliar o efeito da Moringa olifera no crescimento e saúde intestinal da tilápia (Oreochromis niloticus). A ração com 30% de proteína bruta foi preparada como dieta experimental com 4%, 8% e 10% de suplementação de folhas de M. olifera, respectivamente. A dieta controle foi desprovida de folhas de M. olifera. O ensaio de alimentação de 10 semanas foi realizado em 60 peixes em aquários. O peixe pesava 3% do peso corporal duas vezes ao dia. A dieta com alto nível de inclusão de folhas de M. olifera aumentou significativamente a taxa de crescimento, taxa de sobrevivência (SR), taxa de crescimento de sobrevivência (SGR) e eficiência de conversão alimentar (FCE) em todos os grupos de tratamento em comparação com o grupo de controle. Da mesma forma, a taxa de conversão de alimentação (FCR) diminuiu gradualmente e foi considerada altamente significativa. Para verificar a saúde intestinal da tilápia, amostras aleatórias foram selecionadas e dissecadas. O ágar nutriente foi usado como meio de cultura para verificar o crescimento das bactérias. O método da placa de Verter foi usado para a contagem de colônias viáveis por contador de colônias. Através do método de coloração, diferentes como Escherichia coli, Salmonella, Shigella e Pseudomonas aeruginosa foram identificados abundantemente no intestino de peixes da dieta controle, mas em menor número nos grupos de dieta de tratamento. Esses resultados mostraram que M. olifera deixa até 10% da proteína dietética e pode ser usado para tilápia do Nilo para um crescimento significativo e microbiota intestinal saudável de peixes.

Abstract The study was conducted to evaluate the effect of Moringa olifera on the growth and gut health of Tilapia (Oreochromis niloticus). The feed having 30% crude protein was prepared as an experimental diet with 4%, 8% and 10% M. olifera leaf supplementation, respectively. The control diet was devoid of M. olifera leaves. The 10 weeks feeding trial was carried out on 60 fish in aquaria. Fish was fed @ 3% of body weight twice a day. Diet with the high level of inclusion of M. olifera leaves significantly increased the growth rate, Survival Rate (SR), Specific Growth Rate (SGR) and Feed Conversion Efficiency (FCE) in all treatment groups compared to the control group. Similarly, Feed Conversion Ratio (FCR) gradually decreased and found highly-significant. To check the gut health of the Tilapia, random samples were selected and dissected. Nutrient agar was used as culture media to check the growth of bacteria. Pour Plate Method was used for viable colonies count by colony counter. Through staining method, the different bacteria such as Escherichia coli, Salmonella, Shigella and Pseudomonas aeruginosa were identify abundantly in the intestine of control diet fish but less number present in treatment diets groups. These results showed that M. olifera leaves up to 10% of dietary protein can be used for Nile tilapia for significant growth and healthy gut microbiota of fish.

Resumo Pseudomonas fluorescens é uma das principais causas de doenças septicêmicas em peixes de água doce, causando graves perdas econômicas e diminuindo a eficiência da fazenda. Assim, esta pesquisa teve como objetivo investigar a ocorrência de P. fluorescens em peixes de tilápia-do-nilo (O. niloticus) no Egito, sequenciamento do gene 16S rDNA e suscetibilidade antimicrobiana. Cepas de P. fluorescens foram detectadas em 32% (128\400) de peixes tilápia-do-nilo aparentemente saudáveis (9%; 36\400) e doentes (23%; 92\400). A maior prevalência foi observada nas brânquias dos peixes, 31,3%, seguida pelo intestino 26,9%, fígado 24,2% e rins 17,6%. Os resultados da PCR para o gene 16SrDNA de P. fluorescens mostraram o gene 16SrDNA em 30% dos isolados examinados. Além disso, a homogeneidade e uma forte relação entre cepas de P. fluorescens foi confirmada usando sequências de 16SrDNA. Além da responsabilidade do gene 16SrDNA na virulência de P. fluorescens. Os resultados dos testes de suscetibilidade antimicrobiana revelaram que todas as cepas foram resistentes à piperacilina (100%), seguida pela ceftazidima (29,7%) e cefepima (25,8%). As cepas de P. fluorescens foram altamente sensíveis à cefotaxima (74,2%), seguida pela ceftriaxona e levofloxacina (70,3% cada). Curiosamente, 29,7% das cepas de P. fluorescens eram multirresistentes a antimicrobianos (MAR).

Abstract Pseudomonas fluorescens is one of the main causes of septicemic diseases among freshwater fish, causing severe economic losses and decreasing farm efficiency. Thus, this research was aimed to investigate the occurrence of P. fluorescens in Nile Tilapia (O. niloticus) fish in Egypt, gene sequencing of 16SrDNA gene, and antimicrobial susceptibility. P. fluorescens strains were detected in 32% (128\400) of apparently healthy (9%; 36\400) and diseased (23%; 92\400) Nile tilapia fish. The highest prevalence was observed in gills of fish, 31.3% followed by intestine 26.9%, liver 24.2%, and kidneys 17.6%. The PCR results for the 16SrDNA gene of P. fluorescens showed 16SrDNA gene in 30% of examined isolates. Moreover, Homogeny and a strong relationship between strains of P. fluorescens was confirmed using 16SrDNA sequences. Beside the responsibility of 16SrDNA gene on the virulence of P. fluorescens. The results of antimicrobial susceptibility tests revealed that all strains were resistant to piperacillin (100%), followed by ceftazidime (29.7%), and cefepime (25.8%). The strains of P. fluorescence were highly sensitive to cefotaxime (74.2%), followed by ceftriaxone and levofloxacin (70.3% each). Interestingly, 29.7% of strains of P. fluorescens were multiple antimicrobial-resistant (MAR).

Resumo A tilápia tem tolerância a altas temperaturas, pode se reproduzir em cativeiro, crescer rápido e tem excelente custo-benefício. Por essas características, esta espécie é de grande interesse na aquicultura e, atualmente, o pescado mais produzido no Brasil. No entanto, com o aumento da produção de tilápias, houve também um aumento na quantidade de resíduos orgânicos, principalmente da filetagem, que descarta 70% dos resíduos. Existem muitos estudos sobre a extração de colágeno da pele de tilápia como alternativa para reduzir esses resíduos e agregar valor comercial. Neste trabalho, a extração do concentrado protéico foi testada utilizando um protocolo ácido, no qual as peles de tilápia foram submetidas a um pré-tratamento em meio ácido e precipitação salina, com variações de tempo e concentração. Após sua extração, a pele foi avaliada quanto a cinzas, umidade, proteína, solubilidade e pH. O concentrado protéico obtido apresentou baixos teores de cinzas, e a umidade está dentro dos apresentados pela literatura. O concentrado protéico apresentou teores de 68,73 a 80,58% de proteína e uma baixa solubilidade entre 4,03 a 6,93%. Em conclusão, a extração ácida é um possível meio de extração de colágeno, e a pele de tilápia é uma boa alternativa para reaproveitar os resíduos gerados na indústria de pescados.

Abstract Tilapia has high-temperature tolerance, can breed in captivity, grow fast, and have excellent cost-benefit. Because of these characteristics, this species is of great interest in aquaculture and, currently, the most produced fish in Brazil. However, by increasing tilapia production, there was also a rise in the amount of organic waste, mainly from filleting, which discards 70% of waste. There are many studies on collagen extraction from tilapia skin as an alternative to reduce these residues and add commercial value. In this work, the extraction of protein concentrate was tested using an acid protocol, in which the tilapia skins underwent a pre-treatment in an acid medium and saline precipitation, with variations in time and concentration. After its extraction, the skin was evaluated for ash, moisture, protein, solubility, and pH. The protein concentrate obtained showed low ash contents, and the humidity is within those presented by the literature. The protein concentrate showed levels from 68.73 to 80.58% of protein and a low solubility between 4.03 to 6.93%. In conclusion, acid extraction is a possible means of collagen extraction, and tilapia skin is a good alternative to reuse waste generated in the fish industry.

ABSTRACT: This study aimed to prepare and characterize Nile tilapia (Oreochromis niloticus) waste meal. The experimental design consisted of three treatments (carcass meal, mechanically separated meat meal - MSM, and head meal) and five replications of each treatment. Yield, microbiological quality, pH, water activity, proximate composition, energy value, mineral composition, fatty acid profile, amino acid composition, color, and particle size fractions and the geometric mean particle diameter (GMD) analyses were performed. Data were subjected to ANOVA, and means were compared by Tukey’s test at P < 0.05. Carcass, mechanically separated meat, and head meals had a protein content of 56.45%, 78.60%, and 50.33%, respectively, a lipid content of 7.16%, 13.15%, and 4.58%, respectively, and an ash content of 32.61%, 4.26%, and 38.41%, respectively. The mean yield of fish waste meals was 13%. Oleic, palmitic, and linoleic acids were the major fatty acids in the three fish waste meals, and glutamic acid, leucine, lysine, and glycine were the major amino acids. Color analysis showed that lightness (L*) ranged from 55.32 to 77.19, redness (a*) from 4.44 to 4.88, and yellowness (b*) from 4.13 to 9.51. The GMD ranged from 0.37 to 0.99 mm. The results indicate that Nile tilapia waste meals have high nutritional value and adequate pH, water activity, and microbiological quality for use in human nutrition. ABSTRACT Oreochromis niloticus carcass MSM treatment Yield pH activity composition profile color (GMD performed ANOVA Tukeys Tukey s 005 0 05 0.05 Carcass 5645 56 45 56.45% 7860 78 60 78.60% 5033 50 33 50.33% respectively 716 7 16 7.16% 1315 13 15 13.15% 458 4 58 4.58% 3261 32 61 32.61% 426 26 4.26% 3841 38 41 38.41% 13% Oleic palmitic leucine lysine L* L (L* 5532 55 55.3 7719 77 19 77.19 a* (a* 444 44 4.4 488 88 4.88 b* b (b* 413 4.1 951 9 51 9.51 037 37 0.3 099 99 0.9 mm nutrition 00 0.0 564 5 56.45 786 6 78.60 503 3 50.33 71 1 7.16 131 13.15 4.58 326 32.61 42 2 4.26 384 38.41 (L 553 55. 771 77.1 (a 4. 48 8 4.8 (b 95 9.5 03 0. 09 56.4 78.6 50.3 7.1 13.1 4.5 32.6 4.2 38.4 77. 9. 56. 78. 50. 7. 13. 32. 38.

RESUMO: Este estudo teve como objetivo preparar e caracterizar farinha de resíduos de tilápia do Nilo (Oreochromis niloticus). O delineamento experimental consistiu em três tratamentos, farinha de carcaça, farinha de carne mecanicamente separada - CMS e farinha de cabeça, e cinco replicatas por tratamento. Foram realizadas análises de rendimento, qualidade microbiológica, pH, atividade de água, composição centesimal, valor energético, composição mineral, perfil de ácidos graxos, composição de aminoácidos, cor, frações granulométricas e o diâmetro médio geométrico das partículas (DMG). Os dados foram submetidos à ANOVA e as médias comparadas pelo teste de Tukey (P < 0,05). As farinhas de carcaça, de carne mecanicamente separada e de cabeça apresentaram teor de proteína de 56,45%, 78,60% e 50,33%, respectivamente, teor de lipídios de 7,16%, 13,15% e 4,58%, respectivamente, e teor de cinzas de 32,61%. 4,26% e 38,41%, respectivamente. O rendimento médio das farinhas de resíduos de peixe foi de 13%. Os ácidos oleico, palmítico e linoleico foram os principais ácidos graxos encontrados nas três farinhas de resíduos de peixe, e o ácido glutâmico, leucina, lisina e glicina foram os principais aminoácidos detectados nas farinhas. A análise de cor mostrou que a luminosidade (L*) variou de 55,32 a 77,19, o vermelho (a*) variou de 4,44 a 4,88 e o amarelo (b*) variou de 4,13 a 9,51. O GMD variou de 0,37 a 0,99 mm. Os resultados indicam que as farinhas de resíduos de tilápia do Nilo apresentam alto valor nutricional e pH, atividade de água e qualidade microbiológica adequados para uso na alimentação humana. RESUMO Oreochromis niloticus. niloticus . niloticus) tratamentos carcaça tratamento pH centesimal energético mineral DMG. DMG (DMG) P 0,05. 005 0,05 0 05 0,05) 5645 56 45 56,45% 7860 78 60 78,60 5033 50 33 50,33% respectivamente 716 7 16 7,16% 1315 13 15 13,15 458 4 58 4,58% 3261 32 61 32,61% 426 26 4,26 3841 38 41 38,41% 13% oleico glutâmico leucina L* L (L* 5532 55 55,3 7719 77 19 77,19 a* (a* 444 44 4,4 488 88 4,8 b* b (b* 413 4,1 951 9 51 9,51 037 37 0,3 099 99 0,9 mm humana (DMG 00 0,0 564 5 56,45 786 6 78,6 503 3 50,33 71 1 7,16 131 13,1 4,58 326 32,61 42 2 4,2 384 38,41 (L 553 55, 771 77,1 (a 4, 48 8 (b 95 9,5 03 0, 09 56,4 78, 50,3 7,1 13, 4,5 32,6 38,4 77, 9, 56, 50, 7, 32, 38,

ABSTRACT. Tilapia masculinization can be induced by oral administration of α-methyltestosterone (MT), which is commonly dissolved in ethanol to be added to the feed. However, there are many benefits in using alternative vehicles, such as oil. The incorporation time, vehicles quantity, safety for handlers, fish and the environment are favorable factors. In fry fed for 35 days under temperature control, we found that masculinization rate was similar in both incorporation vehicles of MT (oil or ethanol) in the concentrations studied (30 and 60 mg MT kg-1 feed). In an experiment, using hormone oil dissolution and oral administration at 30 mg MT kg-1 feed, it was observed that the longer the administration time, the lower the coefficient of variation in the masculinization rate. Therefore, administration for 32 days showed the lowest variability in the masculinization rate (99.8 ± 0.5 %), compared to 24 (98.5 ± 3.0 %), 16 (97.0 ± 6.0 %) and 8 (89.0 ± 8.8 %) days. The field experiment confirmed the results obtained in the lab. We concluded that the oil can be used as MT vehicle and we recommend to dispense it at the lowest hormonal concentration (30 mg MT kg-1 feed) for 32 days for tilapia masculinization. ABSTRACT αmethyltestosterone α methyltestosterone MT, , (MT) feed However time quantity handlers factors 3 control (3 6 kg1 kg 1 kg- . Therefore 99.8 998 99 (99. 05 0 5 0. %, % 2 98.5 985 98 (98. 3. 97.0 970 97 (97. 6. 89.0 890 89 (89. 88 8. lab (MT ( 99. 9 (99 98. (98 97. (97 89. (89 (9 (8

ABSTRACT Processing residues are still one of the main obstacles in the fishing industry due to waste and environmental impact. With that, ways of reusing these residues are researched to generate new products with different applications. The objective of this work was to develop and evaluate protein films obtained from mechanically separated meat (MSM) of Nile tilapia (Oreochromis niloticus) filleting residues. To get the films, the casting technique was used, varying their composition in relation to the amount of protein (1.0, 1.5 and 2.0%) and glycerol (0.0, 0.1 and 0.2%), creating a 32 factorial plan, with 9 treatments. The films were characterized in terms of color, opacity, water solubility, mechanical properties and water vapor permeability (WVP). In the end, a yield of 18.70% of Nile tilapia myofibrillar proteins (MPs) and a post-lyophilization protein content of 87.33% were obtained. It was concluded that the film that presented the best result in all the characteristics analyzed was the one with 1.0% of MPs and 0.1% of glycerol. impact applications MSM (MSM Oreochromis niloticus used 1.0, 10 1 0 (1.0 15 5 1. 2.0% 20 2 0.0, 00 (0.0 01 0. 0.2%, 02 0.2% , 0.2%) 3 plan treatments color opacity solubility WVP. WVP . (WVP) end 1870 18 70 18.70 (MPs postlyophilization post lyophilization 8733 87 33 87.33 1.0 (1. 2.0 0.0 (0. 0.2 (WVP 187 7 18.7 873 8 87.3 (1 2. (0 18. 87. (

Abstract Tilapia is one of the most important aquaculture species due to the desirable characteristics as easy reproduction and quick growth in several farming systems, including the recirculating aquaculture systems RAS. In this, the high flow of water to remove waste casually stimulates the fish to swim backset, and growth performance may be improved. Increasing the speed of swimming can improve performance within certain limits, in which however if exceeded can be harmful. Fish may be exhausted leading to impaired growth or even mortality. The objective of this work was to evaluate the growth performance of tilapia juveniles under sustained swimming exercise at different speeds. Additionally, the fish stocking density effect was tested in the sustained swimming exercise condition. In the first experiment, Nile tilapia juveniles were submitted in triplicates to sustained swimming exercise in speeds of control (not exercised), 1 BL/s (body length per second), 1.5 BL/s and 2 BL/s. In the second experiment, two fish stocking densities were tested in triplicates in sustained swimming exercise in speed of 2 BL/s and control not exercised. Fish growth performance was improved by sustained swimming exercise in speeds up to 2 BL/s. No expressive fish mortalities were observed in both experiments. The comparison between the two stocking densities does not allow us to safely say tilapia can be reared at stocking densities in order of 1,000 fish/m3, even under sustained swimming exercise. Other densities need to be tested. RAS backset limits harmful mortality Additionally condition experiment exercised, exercised , exercised) BLs BL s body second, second) 15 5 1. experiments 1000 000 1,00 fishm3 fishm m3 m fish/m3 100 00 1,0 fish/m 10 0 1,

Abstract Taurine is considered a conditionally essential amino acid for fish, so its supplementation may improve feed conversion. This study evaluated the supplementation of taurine on growth performance, hematological and immunological parameters, production costs, and survival of Nile tilapia (Oreochromis niloticus) juveniles raised in a recirculating aquaculture system (RAS). A control diet was formulated with 360 g kg-1 of crude protein without fish meal and without taurine supplementation (Control). From the control diet, another diet supplemented with 9.7 g of taurine per kg of feed (Taurine) was produced. Fish fed diet supplemented with taurine had lower daily average weight gain and final average weight compared to the control diet (p < 0.05). It was observed that taurine had no influence on condition factor, survival, or hemato-immunological parameters of Nile tilapia juveniles, but there was a higher mean corpuscular volume and greater nitrogen retention in fish from the control group (p < 0.05). It is concluded that Nile tilapia juveniles do not benefit from taurine supplementation in RAS, even when fed diet containing plant-based protein sources. conversion performance costs Oreochromis niloticus RAS. RAS . (RAS) 36 kg1 1 kg- Control. Control (Control) 97 9 7 9. (Taurine produced p 0.05. 005 0.05 0 05 0.05) factor hematoimmunological hemato plantbased plant based sources (RAS 3 (Control 00 0.0 0.