Abstract Introduction: Semaprochilodus laticeps is a freshwater fish species native to the Orinoco Basin that is exploited in Colombia at two different stages of its life cycle: fry (for the ornamental trade) and adults (for the consumer market). This double exploitation of juveniles and adults raises concerns about the population stability of the species. Objective: To evaluate the sustainability of the exploitation of the species in these two life stages. Methods: 1 277 specimens of S. laticeps were sampled between June and December 2017. Population parameters were estimated from length-frequency data using ELEFAN 1 routine of the FISAT II package. Length at first maturity (Lm) and length at maximum yield (Lopt) were determined using the Froese and Binohlan equations. Virtual population analysis was performed based on Jones length cohort analysis. Results: Population parameters were as follows: K = 0.75, L∞ = 53.1 cm LE, Z = 2.92 yr-1, M = 1.24 yr-1 and F = 1.68. Lm was estimated to be 29.6 cm SL and Lopt at 33.4 cm SL. Of note, 96.3 % of the fish caught in the consumer fishery exceeded Lm and 80 % exceeded Lopt. The results of the virtual population analysis suggested that a very low proportion (0.85 %) of the population was caught as fry, possibly due to natural mortality. Conclusions: Based on the results, as no indicators of overexploitation were identified, it is recommended to continue with the dual use of S. laticeps. It is recommended to maintain the existing conservation measures, such as the closed season during the reproductive period, to ensure sustainable fishery exploitation. The results obtained can serve as a reference to analyze the situation of other species currently fished for both the ornamental (fry) and food (adult) markets.

Resumen Introducción: Semaprochilodus laticeps es una especie de pez de agua dulce originaria de la cuenca del Orinoco, explotada en Colombia en dos etapas distintas de su ciclo de vida: alevín (para el comercio ornamental) y adulto (para el mercado de consumo). Esta doble explotación de alevines y adultos genera preocupación sobre la estabilidad poblacional de la especie. Objetivo: Evaluar la sostenibilidad de la explotación de la especie en estas dos etapas de vida. Método: Entre junio y diciembre de 2017 se muestrearon 1 277 ejemplares de S. laticeps. Los parámetros poblacionales se estimaron utilizando datos de frecuencia de tallas con la rutina ELEFAN 1 del paquete FISAT II. La longitud de primera madurez (Lm) y la de máximo rendimiento (Lopt) se determinaron mediante ecuaciones de Froese y Binohlan. El análisis de la población virtual se realizó basándose en el análisis de cohorte de longitud de Jones. Resultados: Los parámetros poblacionales fueron los siguientes: K = 0.75, L∞ = 53.1 cm LE, Z = 2.92 año-1, M = 1.24 año-1 y F = 1.68. Lm se estimó en 29.6 cm SL y Lopt en 33.4 cm SL. En particular, el 96.3 % del pescado capturado en la pesquería de consumo superó Lm y el 80 % superó Lopt. El análisis de la población virtual sugirió que una fracción muy baja (0.85 %) de la población fue capturada como alevines, posiblemente atribuible a la mortalidad natural. Conclusiones: Con base en los hallazgos, al no identificarse indicadores de sobreexplotación, se recomienda continuar con el doble uso de S. laticeps. Se recomienda mantener las medidas de protección existentes, así como una veda durante el período reproductivo, para garantizar una explotación pesquera sostenible. Los resultados obtenidos pueden servir como referencia para analizar la situación de otras especies actualmente capturadas para el mercado tanto ornamental como de consumo.

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.

SIGNIFICANCE: The Freshwater Biodiversity Information System (FBIS) is a powerful, open-access platform for hosting, sharing, and analysing freshwater biodiversity data for South Africa. Platform design and functionality were strongly informed by the requirements of key data end-users and decision-makers. The platform has over 790 000 occurrence records, which are freely available to data-users and are now being converted into impact through incorporation in national decision-support tools. With better data comes better decisions, and access to a data repository like FBIS means that the monitoring, management and conservation of our freshwater ecosystems can be improved, for the long-term betterment of both people and biodiversity.

The number of people on Earth and human activities are currently taking on frightening proportions with far-reaching consequences for our planet, its biodiversity and ultimately the human race itself. Ten thousand years ago, humans represented 1% of the total biomass of all land vertebrates. The rest was made up by wild animals. Currently, humans, livestock and pets make up 99% of terrestrial vertebrate biomass, while wild animals represent only 1%. It took millennia for the human population to reach the 1 billion mark and that only by 1890. By 1960, however, the world population had grown to 3 billion. Today there are 8 billion people living on our planet. According to Population Matters, the world population will be approximately 10,4 billion by the end of this century, despite the gradual decline in the growth rate in some countries. There is only a 23% chance that the total population growth rate will tail off before 2100. The population of the 47 least developed countries is likely to triple between 2017 and 2100 to around 3 billion. There are currently 62 million people in South Africa. About 67,9% of our population (in 2021) live in urban areas. The South African population grew by 0,87% in 2023. The fertility rate is 2,30 (2023). It is estimated that by 2050 75,5 million people will be living in South Africa, with 8 out of every 10 people living in urban areas, which would significantly increase the pressure on infrastructure. The Global Footprint Network states that humans currently use the resources of 1,75 Earths. If the situation does not improve, by 2050 we would need the equivalent of three Earths to survive. More than 4 billion people will have little or no water by 2050, and South Africa even now has been classified as a "water-stressed" country. Medical science is continually contributing to more babies surviving their entry into the world and to our living increasingly longer. Life expectancy has risen from 46 years in 1950 to 73,2 years in 2023. By 2050 it will be 77 years. What can be done? Empowerment of women is important. Population growth can be curbed to a reasonable extent by giving more girls access to education. This certainly does not mean that girls or women alone should be held responsible for the current population growth, but much more will have to be done about sex education, women's rights will have to be actively promoted and there will have to be better provision and use of contraceptives. Obviously, these issues should be approached and handled with due caution. In this regard, countries such as Thailand and South Korea have, in the recent past, proved that good education may result in lower birth rates. In Africa, women with no education have an average of 5,4 children; women who completed high school an average of 2,7 children and women with tertiary education an average of 2.2. In Nigeria, every year of school attendance by girls cuts the birth rate by a tenth. In addition, intensified efforts to reform economies and societies should be considered. For the sake of the survival of the human species and the sustainability of the Earth, ecological and economic justice and the empowerment ofwomen have to be encouraged. The Millennium Project - a global participatory think tank that was founded in 1996 under the auspices of the American Council for the United Nations University, but which became independent in 2009 and has since grown into a global network of institutions and individuals - aims to improve humankind's prospects for a better future. It recommends, among other things, the following: • Support a policy aimed at improving the survival of children, responsible family planning and educational opportunities for (especially) girls. • Improve methods that will ensure skills and employment opportunities for young people, as well as care and services for the elderly. • Implement the UN's urban agenda. • Create enough smart cities where citizens with urban intelligence can help in eco-smart ways with the necessary improvements in the city. • Increase training in resilience, and improve disaster prediction and management. • Provide guidance for people about urban ecology. • Intensify research and development in saltwater agriculture (halophytes or salt plants) on coastlines to produce food for humans and animals, biofuel and pulp for the paper industry, and to absorb carbon dioxide (CO2). This will ease the pressure on freshwater agriculture. • Improve agricultural and irrigation management. • Invest in precision agriculture and aquaculture. • Reduce food losses from the "farm to the mouth" (one third or 1,3 billion tons of agricultural production is wasted in this way every year). • Establish seaweed to restore wild fish populations along coastlines. The World Bank estimates that 90% of marine life is completely depleted. • Expand the production of insects for animal feed and human diets (insects have a low environmental impact, and 2 billion people already supplement their diet with insects today). • Encourage vegetarianism. Although there are more ways to address these important global challenges, responsible family planning remains one of the most important. This is an extremely sensitive issue for many people (especially in Africa), but if it is not promoted in a humane, informed and responsible way, the sustainability of life on our planet will increasingly come under tremendous pressure in various respects.

Die aantal mense op aarde en hulle/ons aktiwiteite neem tans skrikwekkende afmetings aan met wydlopende gevolge vir ons planeet, biodiversiteit en uiteindelik onsself. Die moderne mens het sy teenwoordigheid op die aarde en die benutting van hulpbronne baie lank as sy onaantasbare reg gesien. Die huidige uitwerking van byvoorbeeld bevolkingsgroei en besoedeling versteur die aarde se natuurlike ritme in so 'n mate dat ons nou nie meer op 'n kitsoplossing kan hoop nie. Die mens se getalle neem teen so 'n tempo toe dat dit nie net nadelig vir die planeet is nie, maar ook vir die mensdom self. Wat kan gedoen word? Bemagtiging van vroue speel 'n belangrike rol. Dit beteken beslis nie dat meisies en vroue alleen vir die huidige bevolkingsgroei verantwoordelik gehou moet word nie. Die bevolkingsgroei kan egter in 'n redelike mate vertraag word deur veral meer meisies toegang tot onderwys en opleiding te gee - asook hul lewensomstandighede te verbeter. Ook sal daar heelwat meer aan seksopvoeding gedoen moet word, vroueregte sal daadwerklik bevorder moet word en daar sal beter voorsiening en gebruik van voorbehoedmiddels moet wees. Uiteraard moet hierdie kwessies met die nodige omsigtigheid benader en hanteer word. In hierdie verband kan onder andere Thailand en Suid-Korea genoem word wat in die onlangse verlede bewys het dat goeie onderwys geboortesyfers laat daal. In Afrika het vroue wat geen onderwys ontvang nie, gemiddeld 5,4 kinders; vroue wat hoërskool voltooi het gemiddeld 2,7 kinders en vroue wat tersiêre studie deurloop het, gemiddeld 2,2 kinders. In Nigerië sny elke jaar wat meisies skool bywoon, die geboortesyfer met 'n tiende. Hiermee saam sal daar ook verskerpte pogings moet wees om ekonomieë en samelewings te hervorm. Ter wille van die mens se voortbestaan en die volhoubaarheid van lewe op aarde moet ekologiese en ekonomiese geregtigheid, en die bemagtiging van vroue aangemoedig word.

Abstract Common duckweeds are flowering plants of the family Araceae, comprising the smallest angiosperms of the plant kingdom, a species of aquatic algae of universal distribution, found on the surface of freshwater bodies, mainly in puddles, swamps, lakes, and calm rivers. Recently, different research has been carried out on its potential and usefulness. Due to its nutritional composition, protein contribution, high fiber content and low fat and carbohydrate content, it would be an adequate input to generate products of high nutritional value, characteristics that make it interesting compared to other species. It is used as a complement to commercial diets in a wide variety of animals such as birds, ruminants, non-ruminants, crustaceans, and fish, reducing feed costs by up to 50 %. Likewise, used in remediation processes of a wide range of chemical contaminants with a high elimination rate, they can absorb some dissolved substances and provide oxygen through photosynthesis. It has been indicated that they are low cost of construction, maintenance, easy to operate, have a wide tolerance to growing conditions, are generally easy to harvest, and do not compete with farmland. In the environmental field, it is important to find alternative and innovative raw materials, even without the need to use growth media or fertilizers, however, their acceptance as a food source needs extensive research regarding their nutritional value, large-scale yield, economic market supply and analysis of antinutritive components for human food.

Resumen Las lentejas de agua son plantas con flores de la familia Aráceas, comprenden las angiospermas más pequeñas del reino vegetal, una especie de algas acuáticas de distribución universal, se encuentran en la superficie de los cuerpos de agua dulce principalmente en charcos, ciénagas, lagos y ríos calmados. Recientemente, se han llevado a cabo diferentes investigaciones sobre su potencial y utilidad. Por su composición nutricional, aporte de proteína, alto contenido de fibra y bajo contenido de grasas y carbohidratos, resultaría ser un insumo adecuado para generar productos de alto valor nutricional, características que la hacen interesante frente a otras especies. Se emplea como complemento a dietas comerciales en una gran variedad animales como aves, rumiantes, no rumiantes, crustáceos y peces, reduciendo hasta un 50 % los costos por alimentación. Así mismo, usada en procesos de remediación de una amplia gama de contaminantes químicos con alta tasa de eliminación, pueden absorber algunas sustancias disueltas y brindar oxígeno mediante la fotosíntesis. Se ha indicado bajo costo de construcción, mantenimiento, fáciles de operar, poseen amplia tolerancia a condiciones de crecimiento, facilidad general de cosecha y no compiten con las tierras de cultivo. En el ámbito ambiental es importante encontrar materias primas alternativas e innovadoras, incluso sin la necesidad de utilizar medios de crecimiento o fertilizantes, sin embargo, su aceptación como fuente de alimento necesita investigaciones exhaustivas con respecto a su valor nutritivo, rendimiento a gran escala, suministro de mercado económico y análisis de componentes antinutritivos para la alimentación humana.

Abstract: We present new ichthyo-archaeological evidence about the native ichthyofauna and ancient fishing practices of the human populations that inhabited Nahuel Huapi lake landscape during the late Holocene. The analysis of fish remains found at the PT1 site on Isla Victoria (Nahuel Huapi National Park, Patagonia, Argentina) allowed us to identify the lacustrine assemblage of native species that included at least 5 species. Our findings also indicate temporal variations in the frequency and diversity of species exploited at the site. Likewise, these data provide valuable insights on native landscapes, specifically in relation to aspects of biodiversity prior to the introduction of exotic species more than 100 years ago. Finally, we discuss significance of the novel and until now underappreciated records in understanding the historical role of fish in sustaining the human populations that inhabited the region, and in identifying processes of change and transformations that occurred in aquatic landscapes over time.

Resumen: En este trabajo aportamos nuevos conocimientos sobre la ictiofauna nativa y la pesca entre las poblaciones humanas que habitaron el paisaje lacustre del Nahuel Huapi durante el Holoceno Tardío a partir de evidencias ictioarqueológicas. El análisis de los restos de peces hallados en el sitio PT1 de la Isla Victoria (Parque Nacional Nahuel Huapi, Patagonia, Argentina) permitió identificar el ensamble lacustre de especies nativas presentes en el pasado que alcanzó al menos cinco especies. Los resultados indican, además, variaciones temporales en la frecuencia y diversidad de especies explotadas en el sitio. Asimismo, estos datos aportan valiosa información sobre los paisajes nativos, específicamente para conocer aspectos vinculados a la biodiversidad antes de la introducción de las especies exóticas realizada hace más de 100 años. Finalmente se discute el carácter novedoso y poco valorado de esta clase de registros tanto para comprender el rol que los peces tuvieron en la subsistencia de las poblaciones humanas que habitaron la región como para identificar procesos de cambio y/o transformaciones que ocurrieron en los paisajes acuáticos a lo largo de la historia.

Abstract 19. This study reports an episode of fish mortality occurred in the Garupá and Pindapoy Grande streams, near the confluence with the Paraná River (Garupá, Argentina). Dead and moribund fish of various species were observed floating on the water surface. Environmental parameters measured were temperature 5 °C, water temperature 15.1 (±0.6) °C, dissolved oxygen 8.7 (±1.2) ppm, pH 7.5 (±0.2), electrical conductivity 67.6 (± 8.8) mS cm-1 and mean depth of 1.7 (±1.0) m. Macroscopic examination of moribund fish revealed corneal opacity, whitish tegument, increased gill mucus, and whitish areas on gill filaments. Microscopic analysis of gills revealed severe generalized epithelial hyperplasia, lamellar fusion, congestion, and inflammatory infiltrate, particularly lymphocytes and eosinophilic granular cells. In addition, microscopic examination allowed the identification of the following ectoparasites found in gills and tegument: Chilodonella, Ichthyophthirius, Dactylogyridae and Trichodinidae, representing 98%, 1.2%, 0.6% and 0.2%, respectively. This study constitutes a novel record of wild fish mortality associated with extreme environmental conditions and parasitosis. Furthermore, our findings are significant as there are no prior reports in Argentina of epizootic cases linked to Chilodonella sp. infection in wild or farmed fish populations, being the first report of chilodonelliasis for this region.

Resumen 23. Este estudio reporta un episodio de mortandad de peces ocurrido en los arroyos Garupá y Pindapoy Grande, cerca de la confluencia con el río Paraná (Garupá, Argentina). En este tramo se encontraron flotando en la superficie del agua, peces moribundos y muertos de diferentes especies. Los parámetros medidos fueron: temperatura ambiental 5 °C, temperatura del agua 15,1 (±0,6) °C, oxígeno disuelto 8,7 (±1,2) ppm, 24. pH 7,5 (±0,2), conductividad 67,6 (± 8,8) mS cm-1 y profundidad media de 1,7 (±1,0) m. En el examen macroscópico de peces moribundos se observó opacidad corneal, tegumento blanquecino, aumento de moco branquial y áreas blanquecinas en los filamentos branquiales. El análisis microscópico de las branquias reveló hiperplasia epitelial generalizada grave, fusión laminar, congestión e infiltrado inflamatorio, particularmente linfocitos y células granulares eosinófilas. Además, el examen microscópico permitió identificar los siguientes ectoparásitos encontrados en piel y branquias: Chilodonella, Ichthyophthirius, Dactylogyridae y Trichodinidae, que representó el 98%; 1,2%; 0,6% y 0,2%, respectivamente. El presente estudio es un nuevo registro de mortandad de peces silvestres relacionada con condiciones ambientales extremas y parasitosis. Además, nuestro hallazgo aporta información valiosa, ya que en Argentina no existen registros de casos epizoóticos asociados a infección por Chilodonella sp. en poblaciones de peces silvestres o de criaderos, siendo el primer reporte de quilodonelliasis para esta región.

Resumo Ao longo das décadas, os ecossistemas ribeirinhos sofreram intensa intervenção humana, resultando em degradação e perda de habitat. Como consequência, muitas espécies de peixes tornaram-se ameaçadas, principalmente em rios onde há grande demanda de água doce. Wallago attu é um bagre de crescimento rápido pertencente à família Siluridae tem boa demanda de mercado com alto teor de proteína e valor nutricional em sua carne. Os dados foram obtidos para concentração de metal no peso corporal úmido e seco em Wallago attu selvagem. Todo o metal foi encontrado no limite permitido, conforme recomendado por diferentes organizações internacionais. O cálcio foi encontrado em maior concentração, enquanto o cádmio em menor concentração. Fe, Zn, Cu, Ni, Mn, K, Na, Ca e Mg apresentaram correlação positiva altamente significativa (P < 0,001) com o peso corporal úmido, exceto Co e Cd que apresentaram correlação não significativa (P > 0,05). Metais como Fe, Cu, Zn, Cd, Pb, K, Ca, Mg e Co apresentaram padrão alométrico negativo com o aumento do peso corporal(P < 0,001) e do comprimento total (em centímetros), exceto para Co e Cd, que indica correlação não significativa (P > 0,05). O presente estudo será útil para avaliar a toxicidade devido à presença de metais pesados para pesquisadores e diferentes organizações de River Chenab, Punjab, Paquistão. décadas humana habitat consequência tornaramse tornaram se ameaçadas doce carne selvagem permitido internacionais Fe Zn Cu Ni Mn K Na P 0,001 0001 0 001 0,05. 005 0,05 . 05 0,05) Pb corporalP centímetros, centímetros , centímetros) Chenab Punjab Paquistão 0,00 000 00 0,0 0,

Abstract Over the decades, riverine ecosystems is suffering from intense human intervention resulting in degradation and habitat loss as a consequence, many fish species become endangered, particularly in rivers where heavy demand is placed on freshwater. Wallago attu is fast growing catfish belongs to the family siluridae has good market demand having high protein content and nutritional value in it’s flesh. The data was obtained for metal concentration in wet and dry body weight in wild Wallago attu. All metal was found under permissible limit as recommended by different international organizations. Calcium was found highest, while cadmium in lowest concentration. Fe, Zn, Cu, Ni, Mn, K, Na, Ca and Mg showed highly significant (P<0.001) positive correlation with wet body weight except Co and Cd showed non-significant (P>0.05) correlation. Metals such as Fe, Cu, Zn, Cd, Pb, K, Ca, Mg and Co shown negative allometric pattern with increasing body weight concentration of Cu, Fe, Zn, Ni, Pb, Mn, Na, Ca and K showed positive relationship (P<0.001) with total length (cm), except for Co and Cd, which indicated non significant correlation (P>0.05). Present Study will helpful to assess toxicity due to presence of heavy metals for researchers and different organizations from River Chenab, Punjab, Pakistan. decades consequence endangered freshwater its it s flesh highest Fe Zn Cu Ni Mn Na P<0.001 P0001 P 0 001 (P<0.001 nonsignificant P>0.05 P005 05 (P>0.05 Pb cm, cm , (cm) P>0.05. . Chenab Punjab Pakistan P<0.00 P000 00 (P<0.00 P>0.0 P00 (P>0.0 (cm P<0.0 (P<0.0 P>0. P0 (P>0. P<0. (P<0. P>0 (P>0 P<0 (P<0 P> (P> P< (P< (P

Resumo A fração solúvel de petróleo (WSF) prejudica os organismos, porém os danos podem variar entre os níveis celular e tecidual. O objetivo do presente estudo foi avaliar o efeito agudo (24 h, 48 h e 72 h) e subcrônico (36 dias) da WSF (0%, 25% e 100%) em juvenis do peixe neotropical predador topo Hoplias aff. malabaricus. Os efeitos da WSF foram avaliados no nível molecular utilizando o ensaio do cometa e o teste do micronúcleo para o dano genômico e no nível morfológico através da identificação histológica de lesões patológicas no fígado. Em ambas exposições (aguda e subcrônica) encontramos baixos níveis de dano no DNA (< 10% de DNA na cauda do cometa) e frequência de micronúcleos não significativa em peixes expostos a WSF. As lesões mais significativas no fígado dos peixes expostos a WSF foram a vacuolização lipídica, hipertrofia e focos de necroses. Como estas lesões foram progressivas e persistentes, sua irreversibilidade pode afetar negativamente o recrutamento dos peixes, mesmo sendo um predador topo resistente.

Abstract Petroleum water soluble fraction (WSF) impairs organisms, but damages may vary among cell and tissue levels. The aim of the present study was to evaluate the acute (24 h, 48 h, 72 h) and subchronic effects (36 days) of WSF (0%, 25% and 100%) in juveniles of the Neotropical top predator fish Hoplias aff. malabaricus. The effects of WSF were evaluated at a molecular level using the comet assay and micronucleus test for genome damage; and at a morphological level through histological identification of liver pathologic lesions. In both acute and subchronic exposure we found low levels of DNA damage (< 10% of comet tail) and non-significant frequency of micronucleus in WSF exposed fish. The most significant liver lesions in WSF exposed fish were fatty vacuolization, hypertrophy and focal necrosis. Since these tissue injuries were progressive and persistent, their irreversibility may negatively affect fish recruitment, even in a such resistant top predator.

Resumo Durante o presente estudo, o estresse oxidativo mediado pelo cobre (Cu) foi medido que induziu danos ao DNA por concentração nos tecidos de peixes, Catla catla (14,45 ± 1,24g; 84,68 ± 1,45mm) (Hamilton, 1822). Os alevinos foram retidos em 5 grupos por 14, 28, 42, 56, 70 e 84 dias do período de exposição. Eles foram tratados com 2/3, 1/3, 1/4 e 1/5 (T1-T4) de 96h de concentração letal de cobre. Os controles foram executados junto com todos os tratamentos para as mesmas durações. Uma significativa (p <0,05) concentração dependente do tempo e da dose de Cu foi observada nas brânquias, fígado, rim, músculos e cérebro de C. catla. Entre os órgãos, o fígado apresentou uma concentração significativamente maior de cobre, seguido por guelras, rins, cérebro e músculos. O acúmulo de cobre nesses órgãos causou uma variação significativa nas atividades das enzimas viz. superóxido dismutase (SOD), catalase (CAT) e peroxidase (POD). A atividade de SOD variou significativamente em resposta ao tempo de exposição de Cu como 56> 70> 42> 84> 28> 14 dias, enquanto a atividade de CAT exibiu uma relação inversa com o aumento na concentração de Cu. A atividade POD mostrou um aumento significativo com um aumento na duração da exposição ao Cu. O ensaio do cometa exibiu dano significativo ao DNA induzido por Cu nos eritrócitos periféricos de C. catla. Entre as quatro concentrações de exposição, 2/3 do LC50 (T1) causou danos significativamente maiores aos núcleos em comparação com o controle. O aumento da atividade de POD e SOD, bem como uma diminuição na atividade de CAT em resposta ao Cu, demonstra o envolvimento de um mecanismo protetor contra espécies reativas de oxigênio (ROS), enquanto o aumento de ROS resultou em maior dano ao DNA. Esses marcadores moleculares mencionados acima podem ser usados de forma eficiente para o biomonitoramento de ambientes aquáticos e conservação da ictiofauna comestível.

Abstract During present study, the copper (Cu) mediated oxidative stress was measured that induced DNA damage by concentrating in the tissues of fish, Catla catla (14.45±1.24g; 84.68±1.45mm) (Hamilton,1822). Fish fingerlings were retained in 5 groups for 14, 28, 42, 56, 70 and 84 days of the exposure period. They were treated with 2/3, 1/3, 1/4 and 1/5 (T1-T4) of 96h lethal concentration of copper. Controls were run along with all the treatments for the same durations. A significant (p < 0.05) dose and time dependent concentration of Cu was observed in the gills, liver, kidney, muscles, and brain of C. catla. Among organs, the liver showed a significantly higher concentration of Cu followed by gills, kidney, brain, and muscles. Copper accumulation in these organs caused a significant variation in the activities of enzymes viz. superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD). The SOD activity varied significantly in response to the exposure time of Cu as 56 > 70 > 42 > 84 > 28 > 14 days while CAT activity exhibited an inverse relationship with the increase in Cu concentration. POD activity showed a significant rise with an increase in Cu exposure duration. Comet assay exhibited significant DNA damage in the peripheral erythrocytes of Cu exposed C. catla. Among four exposure concentrations, 2/3rd of LC50 (T1) caused significantly higher damage to the nuclei compared to control. Increased POD and SOD activity, as well as a decrease in CAT activity in response to Cu, demonstrates the involvement of a protective mechanism against reactive oxygen species (ROS), whereas increased ROS resulted in higher DNA damage. These above-mentioned molecular markers can be efficiently used for the biomonitoring of aquatic environments and conservation of edible fish fauna.

Resumo A salinidade é um dos parâmetros ambientais mais críticos em relação à fisiologia dos peixes, modificando a ingestão de alimentos e o desempenho de crescimento em muitas espécies. O presente estudo investigou os efeitos de diferentes níveis de salinidade no desempenho de crescimento, alimentação e sobrevivência de jovens espécies de robalos asiáticos Lates calcarifer, as quais foram criadas sob salinidade 0 (T1), 5 (T2), 22 (T3), 36 (T4) e 42 (T5) ppt. Aproximadamente 830 indivíduos de peixes com peso médio de 1,24 ± 0,52 g foram distribuídos aleatoriamente (166 peixes / tanque) em cinco tanques de concreto (cada tanque tinha 30 × 6 × 4 pés (9,1 x 1,8 x 1,2 metros), com volume de 19,12 litros) por 40 dias. Os peixes foram inicialmente alimentados com uma dieta contendo 42% de proteína bruta a uma taxa de 6% do seu peso corporal por dia. Os resultados mostraram que o nível de salinidade teve um efeito significativo no ganho de peso (GP), ganho de peso médio diário (GPMD), taxa de crescimento específico (TCE), taxa de conversão alimentar (TCA), taxa de sobrevivência (TS), biomassa total e índices de saúde (p < 0,05). O maior GP (39,11 ± 1,49 g), GPMD (1,00 ± 0,12 g), TCE (8,74 ± 0,03% d-1) e o menor TCA (0,96 ± 0,20) foram observados com o tratamento T3, que foi significativamente superior em comparação com os outros tratamentos (p < 0,05). Entre os índices de saúde, os maiores índices hepatossomáticos e viscerossomáticos foram encontrados no tratamento T3, significativamente superior do que os demais grupos (p < 0,05). Não foram encontradas diferenças significativas entre os tratamentos quanto à TS (p > 0,05), mas a TS máxima (98,89 ± 0,0%) foi observada nos tratamentos T3 e T2. O nível máximo de proteína bruta (19,99 ± 1,4%) foi encontrado na composição bioquímica dos corpos dos jovens robalos asiáticos no grupo T3. A regressão polinomial de segunda ordem mostrou que a salinidade de 20 ppt é ótima para o melhor crescimento do robalo asiático. Assim, o presente estudo recomenda salinidade de 20 a 36 ppt para o cultivo comercial de robalo asiático em sistema de aquicultura fechado.

Abstract Salinity is one of the most critical environmental parameters regarding fish physiology, modifying food intake and growth performance in many fish species. The present study has investigated the effects of different salinity levels on growth performance, feeding and survival of Asian seabass Lates calcarifer juveniles. Asian seabass juveniles were reared at 0 (T1), 5 (T2), 22 (T3), 36 (T4), and 42 (T5) ppt salinity. Approximately eight hundred thirty fish individuals with an average weight of 1.24±0.52 g were randomly distributed (166 fish/Tank) in 5 concrete tanks (each tank 30×6×4 ft, volume 19,122 L) for forty days. Juveniles were initially fed 42% crude protein-containing diets at a rate of 6% of their body weight per day. The results showed that salinity level had a significant effect on the weight gain (WG), average daily weight gain (ADWG), specific growth rate (SGR), feed conversion ratio (FCR), survival rate (SR), total biomass and health indices (p<0.05). The highest WG (39.11±1.49 g), ADWG (1.00±0.12 g), SGR (8.74±0.03% d-1) and lowest FCR (0.96±0.20) were observed with T3 treatment, which was significantly higher compared to other treatment groups (p<0.05). Among the health indices, the highest hepatosomatic index and viscerosomatic index were found with T3 treatment, significantly higher than the other groups (p<0.05). No significant differences were found among the treatments in terms of survival rate (p>0.05), but the maximum survival rate (98.89±0.0%) was observed in the T3 and T2 treatments. The maximum level of crude proteins (19.99±1.4%) was found in the whole-body biochemical composition of Asian seabass juveniles in the T3 treatment group. The second-order polynomial regression showed that 20 ppt salinity is optimum for the best growth of Asian seabass. Thus, the present study recommends 20 to 36 ppt salinity for the commercial farming of Asian seabass under a closed aquaculture system.

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 infecção por micobactérias não tuberculosas é uma das doenças bacterianas crônicas mais comuns em peixes ornamentais de aquário e parece estar diretamente relacionada a práticas de manejo estressantes. Além disso, também representa potencial zoonótico. Aqui, apresentamos o isolamento e a caracterização de micobactérias não tuberculosas de peixes-anjo de água doce doentes (Pterophyllum scalare) em São Paulo, Brasil. Foram avaliadas nove fêmeas reprodutoras descartadas com sinais de doença. Os peixes exibiam letargia, perda de apetite, caquexia, úlceras cutâneas e exoftalmia. Na necropsia, quatro peixes apresentaram granulomas macroscópicos no baço. Mycobacterium chelonae, M. fortuitum, M. gordonae, M. intracellulare e M. peregrinum foram isolados e identificados por análise de restrição por PCR de hsp65. A análise histopatológica revelou lesões microscópicas compatíveis com micobacteriose, e o bacilo de Mycobacterium foi observado pela coloração de Ziehl-Neelsen. Notavelmente, todas as espécies de Mycobacterium identificadas neste estudo já foram relatadas em pacientes humanos; portanto, animais doentes podem ser uma fonte de infecção para pessoas que manipulam peixes e aquários.

Abstract Nontuberculous mycobacteria infection is one of the most common chronic bacterial diseases in ornamental aquarium fish and appears to be directly related to stressful husbandry practices. Furthermore, it also represents zoonotic potential. Here we present the isolation and characterization of non-tuberculous mycobacteria from diseased freshwater angelfish (Pterophyllum scalare) in São Paulo, Brazil. Nine discarded breeding females with signs of disease were evaluated. The fish exhibited lethargy, loss of appetite, cachexia, skin ulcers, and exophthalmia. At necropsy, four fishes presented macroscopic granulomas in the spleen. Mycobacterium chelonae, M. fortuitum, M. gordonae, M. intracellulare and M. peregrinum were isolated and identified by hsp65 PCR restriction analysis. Histopathological analysis revealed microscopic lesions compatible with mycobacteriosis, and Mycobacterium bacillus were observed by Ziehl-Neelsen stain. Notably, all Mycobacterium species identified in this study have already been reported in human patients; therefore, diseased animals may be a source of infection for people who handle fish and aquariums.

Resumo Ligula intestinalis é um parasita cestódeo que acomete peixes de água doce em diversos países do mundo. O presente estudo visa revelar a diversidade filogenética, genética e de haplótipos das sequências do gene mt-CO1 enviadas ao banco de dados do NCBI de diferentes países, por meio de análise in-silico. As sequências gênicas de 105 mt-CO1 (371 pb) de L. intestinalis obtidas do NCBI foram utilizadas para análises bioinformáticas. As sequências foram submetidas a análise filogenética e de haplótipos. Como resultado da análise de haplótipos de L. intestinalis, 38 haplótipos foram obtidos de 13 países diferentes. Hap24 constituiu 44,76% da rede de haplótipos obtida. Mudanças nos nucleotídeos entre os haplótipos ocorreram em 1-84 pontos diferentes. A China e a Turquia apresentam os maiores valores do índice de fixação (Fst), 0,59761, enquanto o menor (-0,10526) foi encontrado entre a Rússia e a Turquia. Este estudo fornece uma linha de base para futuros estudos em larga escala sobre epidemiologia, aspectos ecológicos, padrão de distribuição, dinâmica de transmissão e dispersão populacional de L. intestinalis em todo o mundo.

Abstract Ligula intestinalis is a cestode parasite that affects freshwater fish in different countries of the world. The current study aims to reveal the phylogenetic, genetic and haplotype diversity of mt-CO1 gene sequences sent to the NCBI database from different countries by using in-silico analysis. The 105 mt-CO1 (371 bp) gene sequences of L. intestinalis obtained from NCBI were used for bioinformatics analyses. Sequences were subjected to phylogenetic and haplotype analysis. As a result of the haplotype analysis of L. intestinalis, 38 haplotypes were obtained from 13 different countries. Hap24 constituted 44.76% of the obtained haplotype network. Changes in nucleotides between haplotypes occurred at 1-84 different points. China and Turkey have highest fixation index (Fst) values of 0.59761, while the lowest (-0.10526) was found between Russia and Turkey. This study provides a baseline for future studies on extensive scale on the epidemiology, ecological aspects, distribution pattern, transmission dynamics and population dispersion of L. intestinalis worldwide.