ABSTRACT This study describes the process of Pomacea patula catemacensis grow-out in outdoor tanks. Experimental juvenile snails (1.5-2 months old) obtained from wild breeding snails were reared using a recirculating aquaculture system (RAS). The present study focused on increasing the surface area of growth tanks to be used by snails without affecting their growth and survival by adding shelters throughout the water column, which also worked to harbor snails. Two treatments were tested; T1: shelters made with curved clay tiles, T2: curved PVC shelters, and control (without shelters) in triplicate. The stocking density was set at 420 ind m-2 in tanks with 1 m3 total volume, and the culture period was 150 days. The final weight of the snails was significantly higher in control and PVC shelter groups (9.14 ± 2.2 and 8.83 ± 2.31 g, respectively), with PVC shelters showing the highest productivity in total biomass (12.03 ± 0.86 kg tank-1, P < 0.05). Final survival (%) was not significantly different among treatments (56.49 ± 1.62 to 58.05 ± 0.62).

ABSTRACT Taurine supplementation has shown survival and feeding efficiency in larval fish development. Thus, the present study aims to evaluate the effects of adding taurine to the longfin yellowtail (Seriola rivoliana) diet for 60 days. Fish (n = 270) were distributed in three treatments: T0 without taurine, T1, and T2, supplemented with taurine at 1 and 2%, respectively. Growth performance, blood serum biochemistry, fatty acid, and amino acid profiles in skeletal muscle were evaluated. Notable improvements (P < 0.05) were observed in T1 and T2 in terms of specific growth rate (SGR) and weight gain (WG). Survival rates (SR) did not show significant differences (P > 0.05). In addition, a decrease was observed in intraperitoneal fat (IPF). Still, an increase was observed in blood parameters, including higher total protein (TP) and globulin (GLO) concentration, as well as a reduction in cholesterol (CHO) levels. Changes in fatty acid profiles were also detected in skeletal muscle with an increase in omega-3 fatty acids (EPA and DHA) and elevation in taurine concentration in T2. The results showed that adding 20 g kg-1 of taurine to the diet improved growth, skeletal muscle, and blood serum biochemistry. Therefore, the use of higher taurine concentrations is recommended in future studies to understand fully the extent of the benefits to longfin yellowtail juveniles.

ABSTRACT Penaeus vannamei, or white shrimp, is an economically significant species that dominates shrimp production and represents a rapidly growing industry. However, the culture faces challenges due to high mortality rates due to bacterial and viral diseases. Unlike vertebrates, shrimp rely solely on their innate immunity for defense against pathogens. Introducing probiotics into shrimp culture can enhance growth, survival rates, and immune responses against disease outbreaks caused by pathogenic bacteria or viruses. Common diseases affecting shrimp farms include vibriosis, white spot disease, acute hepatopancreatic necrosis and black gill disease. These diseases can cause severe infections, which lead to high mortality rates. The application of probiotics, such as Bacillus cereus, B. licheniformis, B. subtilis, Lactobacillus sp., Paenibacillus, Pseudomonas sp., Pseudoaltermonas, and yeast, either through diet or direct administration, has demonstrated positive impacts on shrimp health, including enhanced growth, increased immunostimulation, improved gut microbiota, and better water quality parameters. In recent decades, aquafeed has explored effective solutions, such as microdiets, co-feeding (combining commercial feed and probiotics), and various microdiets types, to address aquaculture disease problems. Combining microdiets containing essential nutrients with probiotics has proven to be safer than antibiotics, which can adversely affect animals and the environment. However, further studies are needed to optimize the efficiency of feeding techniques by incorporating probiotics and commercial feed for disease resistance in penaeid shrimp culture. This review discusses commercial feeds and microdiets incorporated with probiotics for P. vannamei culture for growth and disease resistance to enhancement.

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.

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 The canonical correlation is used to correlate groups of distinct variables. The objective of this study was to use canonical correlation analysis to evaluate the interaction between water quality attributes clogging-causing and the hydraulic performance of non-pressure compensating drippers operating with dilutions of aquaculture effluent in well water. The experiment was in a completely randomized design in a split-split-plot scheme with three replicates, with five dilutions in the plots (Dilution 1: 100% aquaculture effluent; Dilution 2: 75% aquaculture effluent + 25% well water; Dilution 3: 50% aquaculture effluent + 50% well water; Dilution 4: 25% aquaculture effluent + 75% well water; and Dilution 5: 100% well water), three emitters in the sub-plots (ST (1.6 L h-1), SL (1.6 L h-1) and NJ (1.7 L h-1)), and three operating times in the sub-subplots (0, 80 and 160 hours, in which 0 hours operating time means the start of evaluations). The statistical analyses performed were correlation matrix and canonical analysis. The canonical correlation analysis indicated that when the concentrations of attributes increase, the hydraulic performance of the drippers decreases. The interaction of this group of attributes indicates that the clogging of drippers operating with the five dilutions of aquaculture effluent in well water occurs by the combined action of physical, chemical, and biological agents. The ST dripper was the least sensitive to the group of quality attributes of the dilutions, whereas the most sensitive was the SL dripper. variables cloggingcausing causing nonpressure non pressure splitsplitplot split plot replicates 1 100 2 75 25 3 50 4 5 water, , water) subplots sub 1.6 16 6 (1. h1, h1 h h-1 1.7 17 7 h-1)) subsubplots 0, (0 8 evaluations. evaluations . evaluations) increase decreases physical chemical agents 10 1. (1 h- (

RESUMO A correlação canônica é usada para correlacionar grupos de variáveis distintas. O objetivo deste estudo foi utilizar análise de correlação canônica para avaliar a interação entre atributos de qualidade da água causadores de entupimento e o desempenho hidráulico de gotejadores não autocompensantes operando com diluições de efluente de aquicultura em água de poço. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema de parcelas subsubdivididas, com três repetições, com cinco diluições nas parcelas (Diluição 1: 100% de efluente de aquicultura; Diluição 2: 75% de efluente de aquicultura + 25% de água de poço; Diluição 3 : 50% efluente de aquicultura + 50% água de poço; Diluição 4: 25% efluente de aquicultura + 75% água de poço; e Diluição 5: 100% água de poço), três emissores nas subparcelas (ST (1,6 L h-1) , SL (1,6 L h-1) e NJ (1,7 L h-1)), e três tempos de operação nas subsubparcelas (início do experimento, 80 e 160 horas, em que 0 horas de operação significa o início das avaliações). As análises estatísticas realizadas foram matriz de correlação e análise canônica. A análise de correlação canônica indicou que quando as concentrações dos atributos aumentam, o desempenho hidráulico dos gotejadores diminui. A interação desse grupo de atributos indica que o entupimento dos gotejadores que operam com as cinco diluições de efluente de aquicultura em água de poço ocorre pela ação combinada de agentes físicos, químicos e biológicos. O gotejador ST foi o menos sensível ao grupo de atributos de qualidade das diluições, enquanto o mais sensível foi o gotejador SL. distintas casualizado subsubdivididas repetições 1 100 2 75 25 50 4 5 poço, poço) 1,6 16 6 (1, h1 h h-1 1,7 17 7 h1, h-1)) 8 avaliações. avaliações . avaliações) aumentam diminui físicos biológicos 10 1, (1 h- (

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 This study aimed to evaluate the use of microalgae meal (Aurantiochytrium sp. and Nannochloropsis spp.) as a substitute for fish oil in the diet of shrimp Penaeus vannamei reared in a clear water system. In the diet of these animals, the concentration of fish oil decreased as microalgae meal was inserted, and these were used in five different substitutions: 0, 25, 50, 75, and 100%. The treatments were carried out in triplicate, and after 49 days of cultivation, the zootechnical parameters and the composition of fatty acids in the animals’ muscles were analyzed. In zootechnical performance, the shrimp obtained an average final weight of 16.59 ± 0.3 g, and the growth was approximately 1.89 ± 0.30 g week−1. In addition, feed conversion was, on average, 1.47 ± 0.28, and survival was greater than 97%. However, no significant difference was observed in these parameters. Regardless of the levels of fish oil replacement by microalgae meal, the composition of fatty acids in the shrimp muscle was ensured, as well as their quantity within groups, such as n-3 and n-6 polyunsaturated fatty acids. Thus, with the results obtained in the present study, it is suggested that it is possible to formulate a high-performance diet without any ingredients of marine origin (fish oil or fish meal), contributing to aquaculture's sustainability.

RESUMEN Antecedentes: La biorrefinería marina es un concepto emergente en la industria que busca maximizar la utilización de los recursos naturales a través de procesos sostenibles y eficientes. Esta se enfoca en el aprovechamiento de recursos marinos en respuesta a la necesidad de encontrar alternativas a los procesos industriales tradicionales que suelen generar grandes cantidades de residuos y consumir recursos de manera no renovable. Objetivo: Realizar una revisión de la literatura científica sobre la importancia de los productos derivados de los desperdicios de la industria acuícola, con un enfoque de biorrefinería en el contexto de la realidad cubana. Desarrollo: Se realizó una búsqueda de información en la literatura científica especializada; sintetizándose lo más importante, se logró definir el concepto de biorrefinería, basado en la utilización de desechos de la industria acuícola, los productos que se obtienen de la misma, así como sus principales características y aplicaciones y se planteó la importancia y ventajas de aplicar este concepto a la realidad cubana. Conclusiones: La biorrefinería a partir de desechos de la industria pesquera, es un enfoque innovador que busca aprovechar al máximo todos sus componentes, incluidos los subproductos y desechos generados, esta estrategia está muy relacionada con los principios de economía circular y promueve la sostenibilidad de la industria.

ABSTRACT Background: The marine biorefinery is an emerging concept in the industry that seeks to maximize the use of natural resources through sustainable and efficient processes. This focuses on the use of marine resources in response to the need to find alternatives to traditional industrial processes that usually generate large amounts of waste and consume resources in a non-renewable way. Aim: Conduct a review of the scientific literature on the importance of products derived from waste from the aquaculture industry, with a biorefinery approach in the context of the Cuban reality. Development: A search for information was carried out in the specialized scientific literature; Synthesizing the most important thing, it was possible to define the concept of biorefinery, based on the use of waste from the aquaculture industry, the products obtained from it, as well as its main characteristics and applications and the importance and advantages of applying this were raised. concept to the Cuban reality. Conclusions: The biorefinery using waste from the fishing industry is an innovative approach that seeks to make the most of all its components, including the by-products and waste generated. This strategy is closely related to the principles of circular economy and promotes the sustainability of the industry.

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 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.

Abstract Introduction: Sea urchin aquaculture is a rising industry, and in consequence, there is a need to establish optimal culture parameters to ensure the health of the cultured animals. Objective: To evaluate the bacterial counts in the seawater of sea urchin (Arbacia dufresnii) aquaculture recirculating systems (RAS). Methods: The bacteriological water quality of two RAS containing sea urchins was determined. For approximately two months, weekly water samples were taken. The bacteriological quality was determined by counting total aerobic heterotrophic populations, lactic acid bacteria, enterobacterias and genus Vibrio. Physicochemical parameters were also measured. Results: There was no presence of disease or mortality. Enterobacteria and lactic acid bacteria were not detected from both RAS systems. The number of animals had an important effect on the observed difference in the count of total bacteria and Vibrio spp. In RAS 1 the maximum counts of total bacteria and Vibrio spp. were 2.8 x 105 ± 1.7 x 105 and 1.45 x 105 ± 3.6 x 104 UFC ml-1, respectively. In RAS 2 total bacteria and Vibrio spp. exhibited repetitive behavior over time influenced in part by water exchange and mainly by feeding. The results indicate that periodic water changes ensure a limited growth of bacterial strains as Vibrio and other bacteria. Conclusions: Our results suggests that the bacterial count levels recorded in this study can be used as a threshold or safety limit for Arbacia dufresnii aquaculture.

Resumen Introducción: La acuicultura de erizos de mar es una industria en auge, y en consecuencia, existe la necesidad de establecer los parámetros de cultivo óptimos para garantizar la salud de los animales en cultivo. Objetivo: Evaluar los recuentos bacterianos en el agua de cultivo de los sistemas de recirculación acuícola (RAS) de erizo de mar Arbacia dufresnii. Métodos: Se determinó la calidad bacteriológica del agua de cultivo de dos RAS que contenían erizos de mar. Durante aproximadamente dos meses, se tomaron muestras de agua semanalmente. La calidad bacteriológica se determinó realizando recuento de las poblaciones heterótrofas aerobias totales, bacterias ácido lácticas, enterobacterias y bacterias del género Vibrio. También se midieron parámetros fisicoquímicos. Resultados: No se observaron patologías ni mortalidad. No se detectaron enterobacterias ni bacterias del ácido láctico en ninguno de los sistemas RAS. El número de animales cultivados tuvo un efecto importante en la diferencia observada en el recuento de bacterias totales y Vibrio spp. En el RAS 1 los recuentos máximos de bacterias totales y Vibrio spp. fueron 2.8 x 105 ± 1.7 x 105 y 1.45 x 105 ± 3.6 x 104 UFC ml-1, respectivamente. En RAS 2 los recuentos de bacterias totales y Vibrio spp. exhibieron un comportamiento repetitivo en el tiempo influenciado en parte por el recambio de agua y principalmente por la alimentación. Los resultados indican que los cambios periódicos de agua aseguran un crecimiento limitado de cepas bacterianas como Vibrio y otras bacterias. Conclusiones: Nuestros resultados sugieren que los niveles de recuento bacteriano registrados en este estudio pueden usarse como umbral o límite de seguridad para la acuicultura de Arbacia dufresnii.

Abstract Introduction: Short-term gametes storage is an inexpensive and simple technique that allows the use of the same batch of eggs or sperm at different times, maximizing the application of research protocols and the use of gametes in production. Arbacia dufresnii is a sea urchin species with proven aquaculture potential and already used in the nutraceutical industry. Aging of its gametes is unknown and is a needed information to scale up the production. Objective: Determine the effect of male and female gamete aging on the fertilization success of Arbacia dufresnii. This will allow optimizing the use of gametes after collection decoupling spawning from fertilization. Methods: A. dufresnii individuals were induced to spawn and gametes were kept at 12 ± 1 °C throughout each bioassay. Sperm was separated into two treatments: activated sperm in seawater (AS), and dry sperm (DS). Two bioassays were made: Bioassay 1 evaluated the effect of time on fertility by performing fertilization tests at 0 h, 24 h, 48 h, 72 h, and 96 h after spawning. Bioassay 2 evaluated the contribution of each type of aged gamete on fertility, combining aged gametes (96 h) with fresh gametes (0 h). Results: Bioassay 1: the fertilization success obtained by combining eggs (E) with AS or DS presented important differences. While the fertilization success remained acceptable (greater than 50 %) for up to 72 h using ExDS, it only remained acceptable for up to 48 h using ExAS. Bioassay 2: acceptable fertilization success was found by combining aged E (96 h) with fresh sperm, or aged DS (96 h) with fresh E, but not using aged AS with fresh E. Conclusions: The findings of this work show that fertilization success in A. dufresnii gametes remains relatively unchanged for up to 48 h after spawning when combining ExAS, and for up to 72 h when combining ExDS. However, when combining aged E or aged DS with a fresh gamete, post-collection fertilization can be extended up to 96 h. In this work, the first steps have been taken to understand the conservation time of A. dufresnii gametes with minimum intervention.

Resumen Introducción: El almacenamiento de gametos a corto plazo es una técnica económica y sencilla que permite utilizar el mismo lote de óvulos o espermatozoides en diferentes momentos, maximizando la aplicación de protocolos de investigación y el uso de gametos en la producción. Arbacia dufresnii es una especie con probado potencial acuícola como fuente de gametos para la industria nutracéutica. Sin embargo, se desconoce el envejecimiento de sus gametos y es una información necesaria para escalar la producción. Objetivo: Determinar el efecto del envejecimiento de los gametos masculinos y femeninos en el éxito de la fecundación de Arbacia dufresnii con el fin de optimizar el aprovechamiento de los gametos después de la recolecta desincronizando el desove de la fecundación. Métodos: Se indujo el desove de individuos de A. dufresnii y los gametos se mantuvieron a 12 ± 1 °C durante cada bioensayo. El esperma se separó en dos tratamientos: esperma activado en agua de mar (AS) y esperma seco (DS). Se realizaron dos bioensayos: El Bioensayo 1 evaluó el efecto del tiempo sobre la fertilidad realizando pruebas de fecundación a las 0 h, 24 h, 48 h, 72 h y 96 h después del desove. El bioensayo 2 evaluó la contribución de cada tipo de gameta envejecida (96 h) sobre la fertilidad, combinando gametos envejecidas (96 h) con gametos frescas (0 h). Resultados: Bioensayo 1: el éxito de fecundación obtenido combinando huevos (E) con AS o DS presentó diferencias importantes. Si bien el éxito de la fecundación se mantuvo aceptable (más del 50 %) durante un máximo de 72 h con ExDS, solo permaneció aceptable hasta 48 h con ExAS. Bioensayo 2: se encontró un éxito de fecundación aceptable combinando E envejecidos (96 h) con esperma fresco, o DS envejecido (96 h) con E fresco (0 h), pero no usando AS envejecido con E fresco (0 h). Conclusiones: Los hallazgos de este trabajo muestran que el éxito de la fecundación en los gametos de A. dufresnii permanece relativamente sin cambios hasta 48 h después del desove cuando se combina ExAS, y hasta 72 h cuando se combina ExDS. Sin embargo, cuando se combina E envejecido o DS envejecido con un gameto fresco, el tiempo entre la recolección y la fecundación puede extenderse hasta 96 h. En este trabajo se han dado los primeros pasos para entender el tiempo de conservación de los gametos de A. dufresnii con mínima intervención.

Abstract Introduction: The aquaculture industry is constantly growing, registering a global production of almost 88 million tonnes by 2020. This industry brings environmental problems if its effluents are not properly treated. In 2020, the first technology-based company of CONICET was established in Argentine Patagonia whose purpose is the aquaculture production of the green sea urchin, Arbacia dufresnii to develop a range of nutraceutical products. Its cultivation system entails a commitment to sustainability since its creation, and yet it generates effluents with high levels of nitrates and phosphates. Objective: Given this scenario, and valuing bioremediation as a water treatment tool, the use of marine microalgae as phytoremediating agents of aquaculture effluent is proposed in this work. Methods: The microalgae Chaetoceros gracilis, Navicula sp., Tetraselmis suecica, Rhodomona salina, Nanochloropsis galvana and Cylindrotheca closterium were use; which are used as food for sea urchins larvae in the production process. An experiment was designed that compares the microalgal growth and the removal capacity of nutrients in the effluent in contrast to the artificial culture medium currently used in the production cycle. Results: It is possible to remedy the aquaculture industry’s effluent by employing the selected microalgae, with a percentage of removal efficiency of 100 % of the nitrate and an average removal efficiency percentage of 50 % for all the microalgae tested. Likewise, significantly higher microalgal biomass values were obtained when the culture was carried out in the effluent the culture in the artificial environment. Conclusions: The advances in research provided in this work show that it is possible to take advantage of a discard to cultivate microalgae, even improving microalgal productivity for use as food, reducing the costs involved in the microalgal production sector by changing the use of the type of current culture medium (F/2) for that from a current discard. These advances, if scaled and validated, can improve industry sustainability standards within the framework of a circular economy.

Resumen Introducción: La industria acuícola está en constante crecimiento, registrando una producción mundial de casi 88 millones de toneladas para el año 2020. Esta industria trae consigo problemas ambientales si sus efluentes no son debidamente tratados. En el 2020, se constituyó la primera empresa de base tecnológica del CONICET en la Patagonia Argentina cuyo propósito es la producción acuícola del erizo verde de mar, Arbacia dufresnii con la finalidad de elaborar una gama de productos nutracéuticos. Su sistema de cultivo conlleva un compromiso de sustentabilidad desde su creación, y sin embargo genera efluentes con niveles altos de nitratos y fosfatos. Objetivo: Ante este escenario, y valorizando la biorremediación como herramienta de tratamiento de aguas, se propone en este trabajo la utilización de las microalgas marinas como agentes fitorremediadores del efluente acuícola. Métodos: Se utilizaron las microalgas Chaetoceros gracilis, Navicula sp., Tetraselmis suecica., Rhodomona salina., Nanochloropsis galvana y Cylindrotheca closterium, las cuales son usadas como alimento de las larvas del erizo en el proceso productivo. Se diseñó un experimento que compara el crecimiento microalgal y la capacidad de remoción de los nutrientes en el efluente en contraste con el medio de cultivo artificial actualmente usado en el ciclo productivo. Resultados: Es posible remediar el efluente de la industria acuícola mediante las microalgas seleccionadas, con porcentaje de eficacia de remoción del 100 % del nitrato y un porcentaje de eficacia de remoción promedio de 50 % para todas las microalgas testeadas. Asimismo, se obtuvieron valores de biomasa microalgal significativamente mayores cuando el cultivo fue realizado en el efluente respecto del cultivo en el medio artificial. Conclusiones: Los avances en investigación proporcionados en este trabajo ponen de manifiesto que es posible el aprovechamiento de un descarte para cultivar las microalgas, incluso mejorando la productividad microalgal para su uso como alimento, disminuyendo los costos involucrados en el sector de producción microalgal cambiando el uso del tipo de medio de cultivo actual (F/2) por el proveniente de un descarte. Estos avances si son escalados y validados, pueden mejorar los estándares de sustentabilidad de la industria en el marco de una economía circular.

Abstract Introduction: Even though only a few species are considered to be dangerous, pests or vectors, the majority of invertebrates produce a feeling of aversion in humans. This has contributed to the delay in the development of ethical considerations as regards this group in contrast with vertebrates, with the exception of cephalopods. Objective: In the present study, we provide an overview of the current situation on animal ethics and welfare in order to contribute to the development of a framework for ensuring invertebrate welfare. Methods: Today, animal welfare is multidisciplinary in nature to a very high degree as it includes ethology, physiology, pathology, biochemistry, genetics, immunology, nutrition, cognitive-neural, veterinary medicine, and ethics. Animal welfare is a complex concept, difficult to achieve successfully from one perspective. Results: As a consequence, we propose to include the five domains (nutrition, environment, health, behaviour and mental state) along with the three conceptions (basic health and functioning, affective state and natural living), as well as the 5R Principle (Replace, Reduction, Refinement, Respect and Responsibility) in seeking to achieve a comprehensive welfare state. Conclusions: We consider that in both research and animal production, the individual and collective ethical concerns coexist and, in fact, the main moral concern to account for is the collective one and that, within that collective view, the individual moral concern should be applied with responsibility and respect for the individual. Finally, we propose a practical example of invertebrate welfare production in sea urchin aquaculture with the aim of including animal production of invertebrates in this important discussion.

Resumen Introducción: Aunque sólo unas pocas especies son consideradas peligrosas, plagas o vectores, la mayoría de los invertebrados producen un sentimiento de aversión en el ser humano. Esto ha contribuido al retraso en el desarrollo de consideraciones éticas respecto a este grupo en comparación con los vertebrados, a excepción de los cefalópodos. Objetivo: En el presente trabajo, proporcionamos una visión general de la situación actual en materia de ética y bienestar animal con el fin de contribuir al desarrollo de un marco para garantizar el bienestar de los invertebrados. Métodos: Hoy en día, el bienestar animal es de naturaleza multidisciplinaria en un grado muy alto, ya que incluye etología, fisiología, patología, bioquímica, genética, inmunología, nutrición, cognitivo-neural, medicina veterinaria y ética. El bienestar animal es un concepto complejo, difícil de lograr con éxito desde una sola perspectiva. Resultados: Como consecuencia, proponemos incluir los cinco dominios (nutrición, ambiente, salud, comportamiento y estado mental) junto con las tres concepciones (Salud básica y funcionamiento, estado afectivo y vida natural), así como el Principio 5R (Reemplazar, Reducir, Refinar, Respetar y Responsabilidad) en la búsqueda de alcanzar un estado de bienestar integral. Conclusiones: Consideramos que tanto en la investigación como en la producción animal coexisten las preocupaciones éticas individuales y colectivas y, de hecho, la principal preocupación moral a dar cuenta es la colectiva y que, dentro de esa visión colectiva, se debe aplicar la preocupación moral individual. con responsabilidad y respeto por la persona. Finalmente, proponemos un ejemplo práctico de producción de bienestar de invertebrados en la acuicultura de erizos de mar con el objetivo de incluir la producción animal de invertebrados en esta importante discusión.

Abstract Introduction: Care towards nutrition is essential for the quality of a sustainable aquaculture product. Since the balance in food affects the growth and production of gametes. The circular economy is made possible through the use of discarded materials. Objective: The aim of this research was to study the fatty acid composition and metabolic pathways in the gametes of Arbacia dufresnii, with a focus on the implications of incorporating shrimp byproducts into aquaculture feeds. Methods: Four different treatments were designed to maintain optimal nutritional quality, particularly in lipids and proteins, based on previous studies. The fatty acid profiles of the feeds and gametes were analyzed by using gas-chromatography, and statistical analyses were conducted to determine significant differences. Results: Significant differences were observed in the abundance (%) of omega-3 (ω-3) and omega-6 (ω-6) fatty acids. The (ω-3) metabolic pathway was more pronounced in the gametes of wild animals and those fed with the experimental feeds. In contrast, the (ω-6) metabolic pathway was less relevant in these groups. The (ω-3) /(ω-6) ratio was highest in the gametes of wild animals. Feeds enriched in fatty acids enhanced their bioaccumulation in the gametes reaching higher concentrations than wild animals. The availability of fatty acids in foods allowed their bioaccumulation in gametes, with concentrations equal to or higher than those observed in animals in their natural environment for certain fatty acids. Conclusions: Incorporating shrimp byproducts in aquaculture feeds demonstrated a promising strategy for resource utilization and organic input generation. The fatty acid composition in the gametes of A. dufresnii was influenced by the diet, highlighting the potential of balanced feeds to enhance the bioaccumulation of essential fatty acids. These findings provide valuable insights for the development of sustainable aquaculture practices and the production of nutritionally enriched seafood products.

Resumen Introducción: El cuidado hacia la nutrición es fundamental para la calidad de un producto acuícola sostenible. Ya que el balance en los alimentos afecta el crecimiento y producción de los gametos. A partir del aprovechamiento de materias de descarte se posibilita la economía circular. Objetivo: El objetivo de este estudio fue investigar la composición de ácidos grasos y las vías metabólicas en los gametos de Arbacia dufresnii, centrándose en las implicaciones de la incorporación de subproductos de camarones en los alimentos de acuicultura. Métodos: Se diseñaron cuatro tratamientos diferentes para mantener una calidad nutricional óptima, especialmente en lípidos y proteínas, basándose en estudios previos. Se analizaron los perfiles de ácidos grasos de los alimentos y los gametos mediante cromatografía de gases, y se realizaron análisis estadísticos para determinar diferencias significativas. Resultados: Se observaron diferencias significativas en la abundancia (%) de ácidos grasos omega-3 (ω-3) y omega-6 (ω-6). La vía metabólica de (ω-3) fue más pronunciada en los gametos de los animales en su entorno natural y aquellos alimentados con los piensos experimentales. Por el contrario, la vía metabólica de (ω-6) tuvo menos relevancia en estos grupos. La relación (ω-3) /(ω-6) fue más alta en los gametos de los animales en su entorno natural. La disponibilidad de ácidos grasos en los alimentos permitió su bioacumulación en los gametos, con concentraciones iguales o superiores a las observadas en los animales en su entorno natural para ciertos ácidos grasos. Conclusiones: La incorporación de subproductos de camarones en los alimentos de acuicultura demostró ser una estrategia prometedora para la utilización de recursos y la generación de insumos orgánicos. La composición de ácidos grasos en los gametos de A. dufresnii fue influenciada por la dieta, destacando el potencial de los alimentos balanceados para mejorar la bioacumulación de ácidos grasos esenciales. Estos hallazgos brindan información valiosa para el desarrollo de prácticas sostenibles en acuicultura y la producción de productos marinos enriquecidos nutricionalmente.