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.

ABSTRACT. Oreochromis niloticus is the most important aquacultural species worldwide. Several countries are interested in repopulating natural or artificial reservoirs with the fry of tilapia (Oreochromis sp.) to develop new fisheries or to enhance the existing ones. However, as tilapia is considered an invasive species, it is essential to check the existence of the species in the place before releasing any fry. Characterization of tilapia species with meristic is unreliable because of existing morphological similarities among species. In this work, the composition of the tilapia species of Laguna El Mastranzo (LEM), Nayarit, Mexico, was explored for the first time through a molecular method using the mitochondrial DNA control region. Three tilapia species (Oreochromis niloticus, O. aureus, and O. urolepis) were found in LEM, and it was confirmed that the two commercial strains (Aquamol and Spring) intended for repopulation were O. niloticus. Seven haplotypes of mitochondrial DNA control region sequences were obtained: three in LEM, three in Aquamol, and one in Spring strains. Before repopulating any reservoir, a molecular verification strategy is recommended to avoid spreading the species. The results of this work represent a glimpse into the genetic material of LEM, Nayarit, Mexico.

ABSTRACT Aquaponics is the cultivation technique that integrates aquaculture with hydroponics. The present work compared two plant production cycles of a hydroponic component of an aquaponic system (tilapia-lettuce-cucumbers) vs. a hydroponic system. The tilapia growth trial lasted 22 weeks in the aquaponic system, during which two plant production cycles -lettuce-cucumber- (seven weeks) were performed. Water quality and environmental variables were recorded, evaluating weight growth and biomass produced in fish rearing. Leaf number, height, and weight were determined in lettuce plants. Stem length and fresh weight were measured in cucumber plants; length, fresh weight, and diameter were determined in cucumber fruit. The results showed that the average tilapia biomass per tank was 33.76 kg m-3 with an average final weight of 592.26 ± 25.45 g fish−1. Lettuce production (plants ha−1) was higher in aquaponics than hydroponics during the first cycle, while in the second one, it was greater in hydroponics. Significant differences (ANOVA, P < 0.05) resulted between treatments in both cucumber production cycles with larger biomass growth in hydroponics than in aquaponics. Cucumber fruit showed larger weight (212.52 ± 18.89 g) and length (14.15 ± 1.75 cm) in hydroponics, thus greater yield (4.97 t ha−1); hydroponics-grown cucumber plants had longer stem lengths (292.51 ± 8.73 cm). In conclusion, the hydroponic system had higher plant production. However, aquaponics provided a double benefit since it produced fish and plants, and the plants used waste from fish rearing without contaminating the environment.

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 Sustainable agriculture allows the efficient use of natural resources, particularly water. This study aimed to compare the water footprint of the lettuce (Lactuca sativa L.) cultivation in two production systems: aquaponic and hydroponic, in order to understand its impact on water resources. Both production systems were established in a shade house in the state of Sonora, Mexico. The experiment was conducted from May 20 to July 29, 2020. The estimation of the WFtotal was calculated by adding the blue water footprints, consumption of water sheet in the development of the crop and of the inputs and materials used in each system (based on information from the scientific literature). The results indicated an average harvested lettuce weight of 0.056 kg (±0.005 kg) in the aquaponic system and 0.097 kg (±0.007 kg) in the hydroponic system. The statistical analysis was evaluated with the Student’s t-test with a significance level of 5%. The estimated BWFs were 0.2941 and 0.1721 m3 kg-1, the WFtotal were 2.6841 m3 kg-1 and 0.1821 m3 kg-1 for the aquaponic system and hydroponic system, respectively, for 19 plants in each system. The values of the WFtotal were high since they represent the sum of the blue water footprints and the WFinputs and materials. The results of this research confirmed the hypothesis proposed as the aquaponic system registered a greater water footprint. However, it is advisable to generate more knowledge on the subject.

Resumen La agricultura sostenible permite el uso eficiente de los recursos naturales, particularmente del agua. El objetivo de este trabajo fue comparar la huella hídrica del cultivo de lechuga (Lactuca sativa L.) en dos sistemas de producción: acuapónico e hidropónico, para conocer su impacto en los recursos hídricos. Ambos sistemas productivos se establecieron en una casa sombra en el estado de Sonora, México. El experimento se realizó del 20 de mayo al 29 de julio de 2020. La estimación de la HHtotal se calculó mediante la suma de las huellas hídricas azules, consumo de lámina de agua en el desarrollo del cultivo) y de los insumos y materiales utilizados en cada sistema (con base en información de la literatura científica). Los resultados indicaron un peso promedio de lechuga cosechada de 0.056 kg (±0.005 kg) en el sistema acuapónico y de 0.097 kg (±0.007 kg) en el sistema hidropónico. El análisis estadístico se evaluó con la prueba t de student con un nivel de significancia de 5%. Las HHA estimadas fueron 0.2941 y 0.1721 m3 kg-1, las HHtotal fueron 2.6841 m3 kg-1 y de 0.1821 m3 kg-1 para los sistema acuapónico y sistema hidropónico, respectivamente, para 19 plantas en cada sistema. Los valores de las HHtotal fueron elevados ya que representan la suma de las huellas hídricas azules y de la HHinsumos y materiales. Los resultados de esta investigación confirmaron la hipótesis planteada, al registrar una mayor huella hídrica el sistema acuapónico. Sin embargo, es conveniente generar mayor conocimiento en el tema.

Resumen En un experimento a escala piloto desarrollado en Brasil, se cultivaron juveniles de tilapia genéticamente mejorada en efluente de tanque séptico seguido de laguna de alta tasa (LAT). Durante las 22 semanas de la investigación se evaluó la combinación de tres tasas de aplicación superficial de nitrógeno amoniacal total (NAT) (0,6; 1,2 y 2,4 kg NAT.ha-1.d-1) y tres densidades de cultivo (3; 6 y 12 peces.m-2). Los tanques de cultivo funcionaron como unidades de pulimento para tratamiento de las aguas residuales, adicionando (con los mejores resultados, alcanzados con la menor densidad de cultivo y 1,2 kg NAT.ha-1.d-1) las siguientes eficiencias de remoción adicionales a las obtenidas mediante el uso de la LAT: 78,3% para nitrógeno total Kjeldahl; 89,1% para nitrógeno amoniacal; 63,9% para fósforo total; 57,2% para demanda química de oxígeno; 2,36 unidades logarítmicas para E. coli. La productividad de los peces se estimó del orden de 2,67 ton.ha-1 para cultivo durante seis meses por año para climas templados, utilizando la población de plancton natural del agua residual doméstica tratada como la única fuente de alimento.

Abstract In a pilot-scale experiment carried out in Brazil, genetically improved farmed tilapia juveniles were reared in septic tank-high rate algal pond (HRAP) effluent. The combination of three total ammonia nitrogen (TAN) surface loading rates (0.6; 1.2 and 2.4 kg TAN.ha-1.d-1) and three fish stocking densities (3; 6 and 12 fish.m-2) was evaluated during a 22-week research. The fish rearing tanks worked as wastewater treatment polishing units, adding (as the best results, achieved with the lowest fish stocking density and 1.2 kg TAN.ha-1.d-1) the following removal figures on top of those achieved at the HRAP: 78.3% total Kjeldahl nitrogen; 89.1% ammonia nitrogen; 63.9% total phosphorous; 57.2% chemical oxygen demand; 2.36 log units E. coli. Fish productivity was estimated at 2.67 ton.ha-1 for fish culture over six month per year in a temperate climate region, using the domestic treated wastewater natural plankton population as the only food source.

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 After 60 days of experimentation, the effect of three diets based on chemical silage (CHS) and black bean sprouts (BS) was evaluated (DC = control diet; D1 = CHS; D2 = BS; D3 = CHS+BS) on enzymatic defense (activity of superoxide dismutase, SOD, and catalase, CAT) in the liver of tilapia, and production parameters (weight gain, protein efficiency rate, survival, feed conversion factor), prior chemical characterization of CHS, BS and the experimental diets (proximate chemical analysis, amino acids, fatty acids, anti-nutritional substances, total phenols (TPH), total flavonoids (TFl) and antioxidant capacity (AC). A randomized block design was applied with three replications using 120 masculinized GIFT tilapia juveniles of average weight of 9.6 ± 0.12 g. TPH, TFlv, and AC were analyzed by Pearson, and correlation coefficient, enzymatic activity, and productive parameters were evaluated with a one-way ANOVA and a Tukey post-hoc test (95%). Survival was 100% in all treatments and there were significant differences (p<0.05) in the effect on diets. The best diet in growth and production parameters in the fish was D3, suggesting a synergy between the components of CHS and BS. This last component was a source of antioxidants that improved SOD and CAT activities, promising health promotion. D3 represents an alternative food for the growth and health promotion of tilapia, prior challenge testing and evaluation with adverse factors, and verifying its efficiency in the following growth stages under real conditions.

RESUMEN Después 60 días de experimentación se evaluó el efecto de tres dietas a base de ensilado químico (EQ) y germinado de frijol negro (GF) (DC = dieta control; D1 = EQ; D2 = GF; D3 = EQ+GF) sobre la defensa enzimática (superóxido dismutasa, SOD, y catalasa, CAT ) del hígado de tilapias y los parámetros de producción (ganancia de peso, tasa de eficiencia proteica, sobrevivencia, factor de conversión alimenticia), previa caracterización química del EQ, GF y las dietas experimentales (análisis químico proximal, aminoácidos, ácidos grasos, sustancias antinutrionales, fenoles totales (CFT), flavonoides totales (FlvT) y capacidad antioxidante (CA). Fue aplicado un diseño de bloques al azar con tres réplicas utilizando 120 juveniles de tilapia var GIFT masculinizados con peso promedio 9.6 ± 0.12 g. El CFT, FlvT y CA fueron analizados mediante Pearson y coeficiente de correlación, la actividad enzimática y parámetros productivos con ANOVA de una vía y a posteriori Tukey (95%). La sobrevivencia fue 100% en todos los tratamientos y hubo diferencias significativas (p<0.05) del efecto entre las dietas, siendo la D3 la mejor en crecimiento y parámetros de producción en los peces, sugiriendo una sinergia entre los componentes del EQ y el GF. Este último fue una fuente de antioxidantes que mejoró las actividades SOD y CAT, prometiendo promoción de la salud. La D3 representa una alternativa alimenticia para el crecimiento y promoción de la salud de la tilapia, previa prueba de desafío y evaluación con factores adversos, y comprobar su eficiencia en las siguientes etapas de crecimiento bajo condiciones reales.

ABSTRACT Hydroponics is the technology of soil-less agriculture, in which plants are grown in an aquatic environment. While aquaponics is a fast-growing food production system that integrates hydroponics with aquaculture (fish farming). The objective of this study was to compare the production of chard (Beta vulgaris var. cicla L.) using a typical hydroponic system and an aquaponic system for tilapia (Oreochromis niloticus) production in a greenhouse. Six independent recirculation systems were used to test production by triplicate. Simple linear regression analysis showed that leaf production rate differed significantly between systems (p < 0.05), where the hydroponic trial produced 3.46 leaves week-1 and the aquaponic trial 1.53 leaves week-1. Plant biomass increased by 53.91 g week-1 in the hydroponic and 38.24 g week-1 in the aquaponic treatment, although these production rates did not differ significantly (p > 0.05). No significant differences were detected in the concentrations of ammonium (NH4 +), nitrite (NO2 -), and phosphate (PO4 +) between the treatments; however, significant differences were found for nitrate (NO3 -) between the systems (p < 0.05). Chard production in the hydroponic system was higher than in the aquaponic system in terms of leaf number and biomass.

RESUMEN La hidroponía es la tecnología de la agricultura sin suelo, en la que las plantas crecen en un medio acuático. Mientras que la acuaponía es un sistema de producción de alimentos en rápido crecimiento que integra la hidroponía con la acuicultura (cultivo de peces). El objetivo de este estudio fue comparar la producción de acelga (Beta vulgaris var. Cicla L.) mediante un sistema hidropónico típico y un sistema acuapónico de producción de tilapia (Oreochromis niloticus) en invernadero. Se utilizaron seis sistemas de recirculación independientes para comprobar la producción por triplicado. Un análisis de regresión lineal simple indicó que la tasa de producción de hojas difirió de forma significativa entre sistemas (p < 0.05), ya que en el hidropónico se obtuvieron 3.46 hojas semana-1, mientras que en el acuapónico fue de 1.53 hojas semana-1. La biomasa vegetal aumentó 53.91 g semana-1 en el tratamiento hidropónico y 38.24 g semana-1 en el acuapónico, aunque dichas tasas de producción no difirieron significativamente (p>0.05). No se detectaron diferencias significativas en las concentraciones de amonio (NH4 +), nitrito (NO2 -), y fosfato (PO4 +) en ambos tratamientos; pero se encontraron diferencias significativas para nitratos (NO3 -) entre sistemas (p < 0.05). La producción de acelgas en el sistema hidropónico fue mayor que en el sistema acuapónico en cuanto al número de hojas y la biomasa.

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:

Abstract A total of 381 specimens of the tilapia Oreochromis mossambicus collected monthly from May 2017 to May 2018 in the Laguna de Los Patos, Cumaná, Venezuela, to evaluate reproductive parameters of this non-native species. Significant differences were found in relation to average height and weight between males and females, with the highest values in males. The sex ratio was 1:1.5 (males:females), which deviates significantly from the expected 1:1 ratio. The mean length of sexual maturity (Lm50) was 18.0 cm in females and 20.1 cm in males, reflecting that females mature at smaller sizes than males. The monthly variations of the gonadosomatic index (GSI) and the stages of sexual maturity show two reproductive peaks during the study, in October 2017 and April 2018, coinciding with the rainy and dry seasons in the region respectively. The condition factor (CF) showed significant differences between months, but not between sexes, with an average of 1.87 in females and 1.84 in males. The average absolute fecundity was 921 ± 604.6 eggs per fish, with a relative fecundity of 8.36 ± 3.09 eggs per gram of fish. Differences in oocyte size in mature females confirm that the species can spawn repeatedly over a period, which is considered an important factor for the establishment of tilapia in non-native environments. 38 201 Patos Cumaná Venezuela nonnative non native 11.5 115 1 1.5 5 1:1. malesfemales, malesfemales , (males:females) 11 1: Lm50 Lm (Lm50 180 18 0 18. 20 20. GSI (GSI study respectively CF (CF months sexes 187 87 1.8 184 84 92 6046 604 6 604. fish 836 8 36 8.3 309 3 09 3.0 period environments 11. 15 1. (males:females Lm5 (Lm5 2 9 60 83 8. 30 3. (Lm

Resumo Um total de 381 espécimes da tilápia Oreochromis mossambicus foram coletados mensalmente de maio de 2017 a maio de 2018, na Laguna de Los Patos, Cumaná, Venezuela, para avaliar parâmetros reprodutivos desta espécie não nativa. Foram encontradas diferenças significativas em relação às médias de altura e peso entre machos e fêmeas, sendo os maiores valores no sexo masculino. A razão sexual foi de 1:1,5 (machos:fêmeas), o que se desvia significativamente da proporção esperada de 1:1. O comprimento médio de maturação sexual (Lm50) foi de 18,0 cm nas fêmeas e 20,1 cm nos machos, refletindo que as fêmeas amadurecem em tamanhos menores que os machos. As variações mensais do índice gonadossomático (IGS) e dos estágios de maturidade sexual mostram dois picos reprodutivos durante o estudo, em outubro de 2017 e abril de 2018, coincidindo com as estações chuvosa e seca na região, respectivamente. O fator de condição (FC) apresentou diferenças significativas entre os meses, mas não entre os sexos, com média de 1,87 no sexo feminino e 1,84 no masculino. A fecundidade absoluta média foi de 921 ± 604,6 ovos por peixe, com fecundidade relativa de 8,36 ± 3,09 ovos por grama de peixe. Diferenças no tamanho dos ovócitos em fêmeas maduras confirmam que a espécie pode desovar repetidamente ao longo de um período, o que é considerado um fator importante para o estabelecimento de tilápias em ambientes não nativos. 38 201 2018 Patos Cumaná Venezuela nativa masculino 11,5 115 1 1,5 5 1:1, machosfêmeas, machosfêmeas , (machos:fêmeas) 11. 11 1. 1:1 Lm50 Lm (Lm50 180 18 0 18, 20 20, IGS (IGS estudo região respectivamente FC (FC meses sexos 187 87 1,8 184 84 92 6046 604 6 604, peixe 836 8 36 8,3 309 3 09 3,0 período nativos 11, 15 1, (machos:fêmeas 1: Lm5 (Lm5 2 9 60 83 8, 30 3, (Lm

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.