ABSTRACT Introduced fish can threaten aquatic biodiversity. Peru is a megadiverse country; its northern coast (Tumbes, Piura, Lambayeque, and La Libertad) exhibits greater fish diversity than its central and southern regions. In this area, introduced species exist; however, no research has been found that consolidates data on them. The aim of this research was to prepare a systematic review of introduced and potentially invasive fish in the northern coast of Peru. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) from 2020, 2,665 documents were obtained from Scopus, WoS, ScienceDirect, SciELO, PubMed, and Google Scholar. After removing duplicate documents and applying inclusion and exclusion criteria, six documents were selected. Eight additional documents were obtained from other sources. A total of 12 introduced species were reported: common carp (Cyprinus carpio), gambusia (Gambusia affinis), guppy (Poecilia reticulata), swordtail (Xiphophorus hellerii), tilapia (Coptodon rendalli), blue tilapia (Oreochromis aureus), Mozambique tilapia (Oreochromis mossambicus), Nile tilapia (Oreochromis niloticus), wami tilapia (Oreochromis urolepis), cobia (Rachycentron canadum), rainbow trout (Oncorhynchus mykiss), and hypostomus (Hypostomus sp.). Of these, five species were cichlids and three were poeciliids; eleven species were found in freshwater, five in mangroves, and two in the sea. Tumbes recorded the highest number of waterbodies with introduced species, Piura recorded the highest number of species (eight), while Lambayeque reported only one species in a waterbody. Seven species (common carp, gambusia, guppy, tilapias - blue, Mozambique, and Nile - and rainbow trout) have a high invasive potential, as they are among the 100 worst invasive species in Europe or worldwide. The evaluated documents have only reported the presence of introduced species without delving into their impact on ecosystems; therefore, further research in this direction would be advisable.

RESUMEN Los peces introducidos pueden amenazar a la biodiversidad acuática. Perú es un país megadiverso; su costa norte (Tumbes, Piura, Lambayeque y La Libertad) presenta una mayor diversidad íctica que su centro y sur. En esta región existen especies introducidas; pero, no se ha encontrado una investigación que consolide los datos sobre las mismas. La investigación tuvo como objetivo preparar una revisión sistemática sobre peces introducidos y potencialmente invasores en la costa norte peruana. Siguiendo las pautas de Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) del 2020, se obtuvieron 2665 documentos de Scopus, WoS, ScienceDirect, SciELO, Pubmed y Google Académico, Tras eliminar documentos duplicados y aplicar los criterios de inclusión y exclusión, se seleccionaron seis documentos. Se añadieron ocho documentos obtenidos de otras fuentes. Se reportaron 12 especies introducidas: carpa (Cyprinus carpio), gambusia (Gambusia affinis), guppy (Poecilia reticulata), pez cola de espada (Xiphophorus hellerii), mojarra (Coptodon rendalli), tilapia azul (Oreochromis aureus), tilapia mosámbica (Oreochromis mossambicus), tilapia nilótica (Oreochromis niloticus), wami tilapia (Oreochromis urolepis), cobia (Rachycentron canadum), trucha arcoíris (Oncorhynchus mykiss) y carachama (Hypostomus sp.). De estas, cinco especies fueron cíclidos y tres poecílidos; once especies se encontraron en agua dulce, cinco en manglares y dos en el mar. Tumbes registró el mayor número de cuerpos de agua con especies introducidas, Piura registró la mayor cantidad de especies (ocho), mientras que en Lambayeque se reportó solo una especie en un cuerpo de agua. Siete especies: carpa, gambusia, guppy, tilapias (azul, mosámbica y nilótica) y trucha arcoíris tienen alto potencial invasor, pues se encuentran entre las 100 peores especies invasoras de Europa o del mundo. Los documentos evaluados solo han reportado la presencia de especies introducidas, sin profundizar en el impacto que han tenido en los ecosistemas; por lo que, sería recomendable realizar investigaciones en esa dirección.

RESUMO O objetivo deste estudo foi avaliar e padronizar a imunomarcação celular de leptina nos ácinos hepáticos da tilápia-do-nilo (Oreochromis niloticus), pela técnica de imuno-histoquímica (IHQ). Para a padronização da técnica de IHQ, foram obtidas amostras de fígado de alevinos de tilápia-do-nilo de 102,10 ± 18,40g. Após o preparo das lâminas por processamento histológico clássico, foi aplicada a técnica de IHQ. Anticorpos policlonais primários antileptina e bloqueador da leptina foram instilados sobre os cortes das lâminas para, depois, serem incubados em câmara úmida overnight. Posteriormente, o kit contendo o anticorpo secundário foi instilado, e as lâminas incubadas em temperatura ambiente. Por fim, os cortes foram contracorados com hematoxilina de Mayer filtrada, após adição do corante DAB. Os ácinos hepáticos foram fotografados e analisados por meio do programa Image J®. A técnica de IHQ permitiu a observação da imunomarcação específica da leptina nos ácinos hepáticos de tilápias-do-nilo, confirmada pelo bloqueio específico da marcação de leptina com o anticorpo inibidor, que obteve o mesmo comportamento que o controle negativo, no qual não foi instilado o anticorpo primário antileptina. Assim, pode-se inferir que a IHQ é uma técnica que pode ser utilizada para estudos futuros sobre fisiologia e nutrição que envolva o hormônio leptina para essa espécie de peixe.

RESUMO: O objetivo foi avaliar parâmetros hematológicos e bioquímicos após teste em novo ambiente, e o desempenho zootécnico de Oreochromis niloticus classificado como proativo ou reativo. No experimento 1, machos de tilápia do Nilo com peso médio de 128,33 ± 34,17 g foram mantidos em sistema de recirculação de água (RAS). Imediatamente após a classificação, foram coletadas amostras de sangue de 20 animais reativos e 20 proativos. No experimento 2 foram classificados 60 machos proativos e 60 reativos, com peso médio de 88,23 ± 21,59 g, os quais foram divididos nos seguintes tratamentos: PT (40 animais proativos), RT (40 reativos) MT (20 proativos + 20 reativos). Os animais foram alimentados duas vezes ao dia durante 90 dias. No experimento 1, os animais reativos apresentaram maior hemoglobina e cortisol e menor quantidade de leucócitos. No experimento 2, o ganho em peso foi maior nos animais proativos (PT) e nos animais reativos (RT); porém, a melhor conversão alimentar foi obtida nos animais reativos. A taxa de sobrevivência foi menor no grupo de animais do tratamento MT. Já a hemoglobina e a glicose tiveram valores inferiores para os animais proativos e para aqueles que estavam misturados, no grupo MT. O colesterol foi superior nos animais PT. Conclui-se que variáveis como hemoglobina, cortisol, leucócitos e colesterol têm maior probabilidade de sofrer alterações entre traços de personalidade. Ainda, pode-se concluir que O. niloticus reativos e proativos, cultivados em ambientes separados, apresentam o mesmo potencial de ganho em peso, porém, a conversão alimentar dos reativos é melhor. RESUMO ambiente reativo 1 12833 128 33 128,3 3417 34 17 34,1 RAS. RAS . (RAS) classificação 6 8823 88 23 88,2 2159 21 59 21,5 tratamentos 40 (4 , proativos) (2 9 dias (PT (RT) porém misturados Concluise Conclui se personalidade Ainda podese pode separados 1283 12 3 128, 341 34, (RAS 882 8 88, 215 5 21, 4 ( (RT

ABSTRACT: To evaluate hematological and biochemical parameters after testing in a new environment, and the zootechnical performance of Oreochromis niloticus classified as proactive or reactive. In experiment 1, male Nile tilapia with an average weight of 128.33 ± 34.17 g were kept in a recirculating aquaculture system (RAS). Immediately after classification, blood samples were collected from 20 reactive and 20 proactive animals. In experiment 2, 60 proactive and 60 reactive males were classified, with an average weight of 88.23 ± 21.59 g, which were divided into the following treatments: PT (40 proactive animals), RT (40 reactive) MT (20 proactive + 20 reactive ). Animals were fed twice daily for 90 days. In experiment 1, reactive animals had higher amounts of hemoglobin and cortisol and lower amounts of leukocytes detected. In experiment 2, weight gain was greater in proactive animals (PT) and reactive animals (RT); however, the best feed conversion was obtained in reactive animals. The survival rate was lower in the MT treatment group of animals. Hemoglobin and glucose had lower values for proactive animals and for those that were mixed, in the MT group. Cholesterol was higher in animals PT. It is concluded that variables such as hemoglobin, cortisol, leukocytes and cholesterol are more likely to undergo changes between personality traits. Furthermore, it can be concluded that reactive and proactive O. niloticus, grown in separate environments, have the same potential for weight gain; however, the food conversion of reactive ones is better. ABSTRACT environment 1 12833 128 33 128.3 3417 34 17 34.1 RAS. RAS . (RAS) classification 2 6 8823 88 23 88.2 2159 21 59 21.5 treatments 40 (4 animals, , animals) (2 ) 9 days detected (PT (RT) however mixed traits Furthermore O environments better 1283 12 3 128. 341 34. (RAS 882 8 88. 215 5 21. 4 ( (RT

Resumen (Objetivo) El objetivo de este estudio fue evaluar la eficiencia antimicrobiana del aceite esencial de diversos quimiotipos de Lippia graveolens contra la cepa Aeromonas hydrophila resistente a la oxitetraciclina, la cual afecta principalmente a la acuicultura de tilapia (O. niloticus) en Guatemala. (Metodología) L. graveolens se colectó en tres departamentos de Guatemala, los aceites esenciales (AE) se obtuvieron mediante hidrodestilación y se caracterizaron mediante cromatografía de gases y espectrometría de masas (GC/MS). Posteriormente, se realizó un ensayo antimicrobiano utilizando pruebas de susceptibilidad en disco y dilución, y se evaluaron las interacciones sinérgicas entre los diferentes quimiotipos. Cada prueba se repitió res veces. (Resultados) El análisis evidenció la presencia de veintisiete compuestos en los AE obtenidos de los quimiotipos, siendo los monoterpenos la clase principal. Los principales constituyentes identificados fueron cis-dihidro-β-terpineol (8.84 %) en el quimiotipo I, carvacrol (51.82 %) en el quimiotipo II y timol (79.62 %) en el quimiotipo III. Todos los AE de los diferentes quimiotipos de L. graveolens demostraron capacidad para inhibir el crecimiento de A. hydrophila. En particular, el quimiotipo timol obtuvo el efecto inhibitorio más fuerte contra el crecimiento bacteriano, con una concentración mínima inhibitoria (CMI) de 92.4 µg/mL y una concentración mínima bactericida (B) de 184.8 µg/mL. Los resultados sugieren que no existe un efecto sinérgico o aditivo al combinar los diferentes quimiotipos de L. graveolens. (Conclusiones) Este estudio constituye el primer reporte sobre la actividad antimicrobiana de los diferentes quimiotipos de L. graveolens contra A. hydrophila resistente a la oxitetraciclina. Los hallazgos sugieren que el quimiotipo timol podría ser un tratamiento potencial para las infecciones en la acuicultura de tilapia en Guatemala.

Resumo (Objetivo) O objetivo deste estudo foi avaliar a eficiência antimicrobiana do óleo essencial de vários quimiotipos de Lippia graveolens contra a cepa Aeromonas hydrophila resistente à oxitetraciclina, que afeta principalmente a aquicultura de tilápia (O. niloticus) na Guatemala. (Metodologia) A L. graveolens foi coletada em três setores da Guatemala, os óleos essenciais (OE) foram obtidos por hidrodestilação e caracterizados por cromatografia a gás acoplada à espectrometria de massas (GC/MS). Posteriormente, foi realizado um ensaio antimicrobianos por meio de testes de suscetibilidade de disco e diluição, e foram avaliadas as interações sinérgicas entre os diferentes quimiotipos. Cada teste foi repetido três vezes. (Resultados) A análise revelou a presença de vinte e sete compostos nos OEs obtidos dos quimiotipos, sendo os monoterpenos a classe principal. Os principais constituintes identificados foram cis-di-hidro-β- terpineol (8,84%) no quimiotipo I, carvacrol (51,82%) no quimiotipo II e timol (79,62%) no quimiotipo III. Todos os OEs dos diferentes quimiotipos de L. graveolens mostraram a capacidade de inibir o crescimento de A. hydrophila. Em particular, o quimiotipo timol obteve o efeito inibitório mais forte contra o crescimento bacteriano, com uma concentração inibitória mínima (CIM) de 92,4 μg/mL e uma concentração bactericida mínima (CBM) de 184,8 μg/mL. Os resultados sugerem que não há efeito sinérgico ou aditivo ao combinar os diferentes quimiotipos de L. graveolens. (Conclusões) Este estudo é o primeiro relatório sobre a atividade antimicrobiana dos diferentes quimiotipos de L. graveolens contra A. hydrophila resistente à oxitetraciclina. Os resultados sugerem que o quimiotipo timol pode ser um tratamento em potencial para infecções na aquicultura de tilápia na Guatemala.

Abstract (Objective) This study aimed to evaluate the antimicrobial efficacy of essential oil (EO) from diverse chemotypes of Lippia graveolens against oxytetracycline-resistant Aeromonas hydrophila, which primarily affects the tilapia aquaculture (O. niloticus) in Guatemala. (Methodology) L. graveolens were collected in three departments in Guatemala. The EO was obtained by hydrodistillation and characterized using gas chromatography and mass spectrometry (GC/MS). Subsequently, an antimicrobial assay was conducted using disk and dilution susceptibility tests and evaluation of synergistic interactions among the chemotypes. Each test was performed in triplicate. (Results) The analysis revealed the presence of twenty-seven compounds in the EO obtained from the chemotypes, with the main class being monoterpenes. The major constituents identified were cis-Dihydro-β-terpineol (8.84%) in chemotype I, carvacrol (51.82%) in chemotype II, and thymol (79.62%) in chemotype III. All EO chemotypes of L. graveolens demonstrated the ability to inhibit the A. hydrophila growth. Thymol chemotype exhibited the strongest inhibitory effect against bacterial growth, with a minimum inhibitory concentration (MIC) of 92.4 µg/mL and a minimum bactericidal concentration (MBC) of 184.8 µg/mL. Furthermore, the results suggest that there is no synergistic or additive effect when combining different chemotypes of L. graveolens. (Conclusions) This is the first report of L. graveolens chemotypes exhibiting antimicrobial activity against oxytetracycline-resistant A. hydrophila. The findings suggest that the chemotype thymol could be a potential treatment for infections in the tilapia aquaculture in Guatemala.

RESUMEN Se evaluó el engorde de tilapia (Oreochromis niloticus) en diferentes densidades (10, 20 y 30 peces/m3) dentro de jaulas flotantes dispuestas en tajamar. Se midieron las variables Ganancia de peso, Ganancia diaria de peso, Largo total, Largo estándar y Altura. Los datos se analizaron según estadística descriptiva, prueba de análisis de varianza (p<0,05) con test de Tukey al 5% de probabilidad de error para Ganancia de peso y Ganancia diaria de peso. Se halló diferencia estadísticamente significativa (p ≤ 0,05) en la Ganancia de peso y Ganancia diaria de peso, donde las Densidades 1, 2 y 3 arrojaron un promedio de 405; 339; 301 gramos y 4,5; 3,77 y 3,35 gramos, respectivamente. La Densidad 1 presentó un promedio de largo total de 30 cm, largo estándar: 25 cm, altura: 11 cm. La Densidad 2, un promedio de largo total de 29 cm, largo estándar: 24 cm, altura: 10 cm. La Densidad 3, un promedio de largo total: 27 cm, largo estándar: 22 cm, altura: 10 cm. Se recomienda la utilización de una Densidad de 10 peces/m3 para el engorde de tilapias (Oreochromis niloticus) en jaulas flotantes dispuestas en tajamar.

ABSTRACT The fattening of tilapia (Oreochromis niloticus) was evaluated at different densities (10, 20 and 30 fish/m3) within floating cages arranged in the cutwater. The variables Weight gain, Daily weight gain, Total length, Standard length and Height were measured. The data were analyzed according to descriptive statistics, analysis of variance test (p<0.05) with Tukey test at 5% probability of error for Weight gain and Daily weight gain. A statistically significant difference (p ≤ 0.05) was found in Weight Gain and Daily Weight Gain, where Densities 1, 2 and 3 gave an average of 405; 339; 301 grams and 4.5; 3.77 and 3.35 grams, respectively. Density 1 had an average total length of 30 cm, standard length: 25 cm, height: 11 cm. Density 2, an average total length of 29 cm, standard length: 24 cm, height: 10 cm. Density 3, average total length: 27 cm, standard length: 22 cm, height: 10 cm. The use of a Density of 10 fish/m3 is recommended for the fattening of tilapia (Oreochromis niloticus) in floating cages arranged in the cutwater.

ABSTRACT. This study evaluated the effects on the growth performance and physiological response (metabolism, hematology, and antioxidant capacity) of the juvenile hybrid red tilapia Oreochromis sp. (initial average weight of 2.82 ± 0.02 g) cultured in seawater with biofloc and fed commercial diets containing 25, 35 and 40% crude protein (P25, P35, and P40, respectively). After seven weeks of bioassay, fish fed P35 and P40 showed no significant differences in weight gain, specific growth rate, and condition factor. The P35 and P40 treatments showed the highest values of growth performance (SGR of 4.85 and 4.43% d-1, respectively) compared to the P25 treatment (4.3% d-1). Otherwise, fish from P35 showed lower activities for metabolic enzymes (ASAT, ALAT, GK, FBPase, G6PD, and FAS) than P40, which suggests that in P35, there was a better use of energy and protein content in the diets. On the other hand, P35 presented values similar to P40 regarding oxidative damage to lipids in the intestinal (5.62 and 5.77 nmol g-1, respectively) and muscle (4.76 and 3.93 nmol g-1, respectively) tissues, but higher than P25 in the liver (1.21 nmol g-1). Finally, the P25 diet triggered a significant decrease in erythrocyte parameters, as well as total protein and albumin in the blood plasma of the fish. In conclusion, marine biofloc allows hybrid red tilapia juveniles to be fed commercial diets with 35% crude protein without compromising their productive performance, antioxidant system, and hematological parameters.

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. 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.

RESUMEN El objetivo del trabajo fue evaluar el efecto de la inclusión del ensilaje de desechos de tilapia roja (Oryctolagus cuniculus) en la dieta de conejos sobre los parámetros productivos y rendimiento económico. El estudio se realizó en Marinilla, Antioquia (Colombia), con 24 conejos machos de 2131 ± 156 g de peso inicial, distribuidos en 3 tratamientos (8 por tratamiento) de tres niveles de inclusión de ensilaje de desechos de pescado; así: T1 (control)= 0%, T2= 15% y T3= 25%, bajo un diseño completamente al azar. A cada animal se le suministró una dieta que consistía en 55 g de alimento balanceado (incluyendo el ensilado) y 120 g de forraje diario durante 42 días. Se registró el peso final, ganancia de peso total, ganancia diaria de peso, peso de la piel y la cabeza, peso de las vísceras rojas, peso de la canal caliente, rendimiento de la canal caliente, peso de la canal fría, rendimiento de la canal fría y conversión alimenticia. No se encontró diferencia estadística entre tratamientos para las variables evaluadas, lo que permitió concluir que la sustitución de alimento concentrado por ensilaje de desechos de pescado hasta en un 25% no afecta los parámetros productivos de conejos; por el contrario, representa una alternativa económica y de fácil elaboración que garantiza ganancias de peso adecuadas y rendimientos en canal idóneos.

ABSTRACT The aim of this study was to evaluate the effect of including tilapia (Oryctolagus cuniculus) waste silage in the rabbit diet on productive parameters and economic performance. The study was carried out in Marinilla, Antioquia (Colombia), with 24 male rabbits of 2131 ± 156 g of initial body weight, distributed in 3 treatments (8 per treatment) of three levels of inclusion of fish waste silage: T1 (control)= 0%, T2= 15% and T3= 25%, under a completely randomized design. Each animal was fed a diet consisting of 55 g of balanced feed (including silage) and 120 g of forage daily for 42 days. The final weight, total weight gain, daily weight gain, skin and head weight, red viscera weight, hot carcass weight, hot carcass yield, cold carcass weight, and feed conversion were recorded. No statistical difference was found between treatments for the variables evaluated, which allows to conclude that the replacement of concentrated feed with fish waste silage up to 25% does not affect the productive parameters of rabbits. On the contrary, it represents an economical and easy-to-produce alternative that guarantees adequate weight gains and ideal carcass yields.

ABSTRACT This study assesses the levels of copper (Cu), chromium (Cr), and cadmium (Cd) in wild and aquacultured Oreochromis niloticus (Tilapia), Micropogonias undulatus (Croaker), and Clarias gariepinus (Catfish) that are sold in Gwagwalada Area Council, Federal Capital Territory, Nigeria. A random sample of 500 g of each species of fish was taken from the markets in Dobi, Gwagwalada, and Zuba. The labels for the composite samples were: aquacultured catfish (Acf), aquacultured tilapia (Atf), aquacultured croaker (Acrf), wild catfish (Wcf), wild tilapia (Wtf), and wild croaker (Wcrf). Oven-dry weight and furnace procedures were used to determine the contents of moisture and ash. Wcf, Wtf, and Wcrf had moisture contents of 4.25±0.354%, 5.25±0.453%, and 4.50±0.000%, respectively, according to the results, whereas Acf, Atf, and Acrf had moisture contents of 7.01±0.230%, 7.12±0.234%, and 6.70±0.210%, respectively. For Wcf, Wtf, and Wcrf, the ash content was 1.75±0.354%, 1.64±0.231%, and 1.48±0.213%, respectively. The possible health concerns linked with the consumption of these heavy metals were determined by measuring and comparing their concentrations. The results show that various fish species accumulate metals at different rates, which could have an impact on public health because extended exposure to these toxins can cause health problems.

RESUMEN El objetivo del presente estudio fue determinar la prevalencia de monogeneos (Cichlidogyrus sp) en tilapia (Oreochromis niloticus) de estadio juvenil en el distrito de la Banda de Shilcayo, región San Martín, Perú. Se colectaron 180 tilapias procedentes de seis piscigranjas de peso y longitud promedio de 37.4 g y 9.56 cm, respectivamente. Se tomaron muestras de tegumento, branquias e intestinos. Se determinó una prevalencia de 76.1% de monogeneos, abundancia de 3.27 monogeneos/pez, intensidad media de 4.28 monogeneos/pez infectado e índice de dispersión de 0.75. Se colectaron 590 parásitos monogeneos del género Cichlidogyrus sp provenientes solo de branquias (100%). No se determinó relación entre la ubicación de los monogeneos dentro de los cuatro arcos branquiales, ni con peso, longitud de los peces y cantidad de monogeneos (p<0.05). Asimismo, las características fisicoquímicas del agua (temperatura, oxígeno, pH, CO2 y amonio) de las piscigranjas se mantuvieron dentro de los rangos normales.

ABSTRACT The aim of the present study was to determine the prevalence of monogeneans (Cichlidogyrus sp) in juvenile stage tilapia (Oreochromis niloticus) in the Banda de Shilcayo district, San Martín region, Peru. In total, 180 tilapias were collected from six fish farms with an average weight and length of 37.4 g and 9.56 cm, respectively. Samples of tegument, gills and intestines were taken. A prevalence of 76.1% of monogeneans, abundance of 3.27 monogeneans/fish, average intensity of 4.28 monogeneans/infected fish and dispersion index of 0.75 was determined. In the study, 590 monogenean parasites of the genus Cichlidogyrus sp were collected only from gills (100%). No relationship was determined between the location of the monogeneans within the four gill arches, nor with weight, length of the fish and number of monogeneans (p<0.05). Likewise, the physicochemical characteristics of the water (temperature, oxygen, pH, CO2 and ammonia) of the fish farms remained within normal ranges.

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.

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.

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 El objetivo del estudio fue aislar, caracterizar e identificar la bacteria Shewanella algae a partir de muestras de órganos internos de tilapias (Oreochromis niloticus) enfermas, las cuales estuvieron cultivadas con tecnología biofloc en Lima, Perú; además, se describieron los cambios histopatológicos provocados por el patógeno. Se muestrearon 85 tilapias que presentaron signos clínicos de enfermedad como exoftalmia, melanosis y nado errático. Se aislaron siete cepas bacterianas las cuales fueron caracterizadas a través de pruebas bioquímicas y confirmadas como S. algae mediante la técnica de PCR y secuenciamiento del gen RNAr 16S. Las cepas mostraron susceptibilidad antibiótica a florfenicol, ácido nalidíxico, gentamicina, flumequina, kanamicina y sulfatrimetoprim. Los hallazgos histopatológicos fueron hiperplasia interlamelar, epicarditis, miocarditis, enteritis, necrosis en estómago y congestión en diversos tejidos.

ABSTRACT The aim of this study was to isolate, characterize and identify the Shewanella algae bacteria from internal organ samples of diseased tilapia (Oreochromis niloticus), which were cultivated using biofloc technology in Lima, Peru; In addition, the histopathological changes caused by the pathogen were described. In total, 85 tilapias were sampled that presented clinical signs of disease such as exophthalmia, melanosis and erratic swimming. Seven bacterial strains were isolated, which were characterized through biochemical tests and confirmed as S. algae using the PCR technique and sequencing of the 16S rRNA gene. The strains showed antibiotic susceptibility to florfenicol, nalidixic acid, gentamicin, flumequine, kanamycin and sulfamethoxazole trimethoprim. The histopathological findings were interlamellar hyperplasia, epicarditis, myocarditis, enteritis, necrosis in the stomach and congestion in various tissues.

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.

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.