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The Peruvian grunt Anisotremus scapularis is one of the most appreciated fish in Peruvian national markets. However, its reduced and irregular fishery is a paradigm of illegal, unreported, and unregulated fishing (IUU) in the Peruvian–Chilean coastal region. An important technological advancement has been achieved in the last decade in capture, management, nutrition, and broodstock maintenance to boost pilot experiences on the aquaculture of this species. Therefore, it is pertinent to evaluate the economic viability of this candidate species to identify cultivation bottlenecks, optimize the process, and assess the transfer feasibility of the technical know-how to interest groups. In this study, we performed a sensitivity analysis to assess how market price and production size should make its commercialization profitable. We show that the use of photovoltaic solar panels and a raw production cycle of 15 months enables profitability at a ~400 k unit farm size at a commercial market price of 6.67 USD/kg, i.e., B/C = USD 1.14. Both, time to market and market price exerted the highest influence on the value of grunt farms; whereas, a reduction of the production cycle to 12 months by seed selection, optimized rearing conditions, and nutritional diets also provides a profitable investment, i.e., NPV = USD 287,054 with an IRR = 23.71% at a discount rate of 10% and B/C = USD 1.15. These scenarios pave the way for the transfer of technological know-how to entrepreneurial initiatives in the economically depressed coastal region of the Atacama Desert.

This study aimed to identify the effects of water temperature on the rearing of the omnivorous teleost Chelon labrosus and to determine the optimal temperature for the culture of this interesting candidate for the diversification of European aquaculture. The fish (initial weight 26.81 ± 6.2 g) were held at four water temperatures (18, 22, 26 and 30 °C) in triplicate for 90 days in 100 L recirculating tanks (n = 14 / tank). The effects of said temperatures were assessed on growth, intestinal health and the digestive processes of the fish. At 18 °C, energy consumption was low, leading to a high accumulation of reserves and slow growth, a typical overwintering strategy. The best growth results were obtained at 22 °C, followed closely by 26 °C, which resulted in low energy reserves. The fact that the fish at 26 °C grew less than the ones at 22 °C while having similar energy consumption, suggested that this temperature was close to the end of the optimal range, but no signs of stress were detected. However, at 30 °C the fish had lower energy reserves but grew significantly less, which can be considered indicative of stress. Health impairment at this temperature was confirmed by the epithelial lesions found in this group. The growth and energy availability of the different groups is discussed in the light of the activities of α-amylase, pepsin and alkaline proteases. As an integration of all these results, a quadratic regression model resulting from growth values (SGR) in relation to water temperature was performed, and it allowed predicting an actual optimal water temperature of 22.8 °C for growth of C. labrosus. This is the first assessment of the optimal water temperature for the culture of C. labrosus , and it will be highly valuable for the development of its intensive culture. • Optimal water temperature for the rearing of Chelon labrosus is 22.8 °C. • Slow growth and high energy reserve accumulation were found at 18 °C. • Some stress signs started at 26 °C, and temperatures of 30 °C were proven to impair animal welfare. • No significant alterations in flesh quality were detected on the tested temperatures. [ABSTRACT FROM AUTHOR]

Crustose coralline algae (CCA) are strong settlement inducers for two exploited limpets, Patella aspera and Patella ordinaria (Patellogastropoda: Patellidae). This study evaluates CCA-conditioned seawater (CSW) as a settlement inducer for the same species through nine assays aimed at its concentration, preservation, production, and as a settlement enhancer for sub-optimal substrates. Two additional assays tested the affinity of limpet larvae to settle on CCA surfaces. Each limpet species showed specific requirements. Settlement of P. aspera was higher in CCA than in CSW, whereas the settlement of P. ordinaria was similar between CCA and CSW. Inductive properties of CSW were nullified by filtration (2.7 μm) and weakened by dilution, but little affected by different preservation methods up to 48 h (room temperature, refrigerated, and autoclave). CSW can be produced serially from different CCA assemblages and preserved frozen during several days. Each limpet species responded differently to CCA and CSW when combined with diatom biofilms. Specific strategies for post larval production are recommended. P. aspera could use CCA-coated structures as collectors designed for limpet settlers in animal production and recruits in the wild; while P. ordinaria may employ movable plates for settlement induction based on CSW. Settlers would require transport to nursery grounds for grow-out. • Coralline algae surface (CCA) attracted settlers of different limpet species. • CCA-coated structures could serve as spat collectors for limpet farming and research. • CCA-conditioned seawater (CSW) can be mass-produced, sterilized, and stored frozen. • CSW is recommended as settlement inducer for generalist limpet species. [ABSTRACT FROM AUTHOR]

Tilapia and catfish are the most popular fish species in aquaponics. However, they are not well-accepted in all markets, and finding alternative species is important in order to increase the variety of food products and meet market demands. South America has several potential fish species for aquaponics systems. Encouraging the implementation of integrated aquaculture systems by providing information about the production of South American species can help to increase the supply of high-quality food and aquaculture diversification. Thus, data for five South American fish species with potential for aquaponics were compared with existing data for the main traditional warm water species in this system, tilapia and catfish. Moreover, the degree of suitability of the novel species for these systems in terms of zootechnical performance, tolerance to water quality and nutritional composition of fish flesh were discussed. The South American species considered were jundia or silver catfish (Rhamdia quelen), yellowtail lambari (Astyanax lacustris), pacu (Piaractus mesopotamicus), tambaqui (Colossoma macropomum) and snook (Centropomus spp.). Their description and the tabular comparison with the most traditional aquaponic-cultured species show they are suited for this production system. How suitable they are will depend on the system design, as well as the regional characteristics of the market where they will be produced. [ABSTRACT FROM AUTHOR]

The New Zealand aquaculture industry is based primarily on the production of Greenshell™ mussels, Chinook salmon and Pacific oysters. The industry is primed for development and is anticipating increasing its export earnings to NZ$3 billion by 2035. To achieve this target and retain its 'clean and green' image, the industry must be able to demonstrate that its practices are sustainable. Integrated multi-trophic aquaculture (IMTA) systems provide an avenue to address this challenge, with most of the work in New Zealand focusing on the integration of low trophic level high-value species such as sea cucumbers and seaweeds with mussels, providing environmental bioremediation and provision of valuable secondary products (nutraceuticals and pharmaceuticals). Ecophysiological, hydrodynamic and benthic diagenesis models have been developed to underpin this IMTA research into sustainable farming designs. However, many regulatory barriers are still in place, which together with the current lack of investment, market security for these new products and associated operational costs form the main constrains to development. Nevertheless, the recent emergence of aquaculture fora where industry, researchers, and regulators meet to discuss future research and development has invigorated interest in diversification of the sector, inclusive of IMTA within existing coastal areas and upcoming land-based and open-ocean operations. [ABSTRACT FROM AUTHOR]

Spotted wolffish Anarhichas minor reproduction in captivity is dependent on in vitro fertilization. However, low sperm volume with relatively low cell concentration and the lack of gametes synchronization (simultaneous availability of mature eggs and sperm) represent a challenge for the industry. Thus, the development of protocols for sperm storage are crucial. Four sequential experiments were conducted to optimize a sperm cryopreservation protocol for this species. First, three different cryoprotectants (DMSO; 1, 2-propanediol; and methanol) at different concentrations (5, 10, and 20%) were tested for their toxicity. No significant differences (p > 0.05) were detected between the control samples and cryoprotectants at concentration up to 10% DMSO, 10% propanediol, and 20% methanol in terms of motility parameters. Second, using the highest non-toxic concentrations of cryoprotectants, sperm was cryopreserved in 0.5 mL straws, at different distances from the liquid nitrogen (1.5, 2.5, 4.5, and 7.5 cm) that correspond to different freezing rates. Motility parameters after freezing/thawing decreased for all the cryoprotectants (p < 0.001), however, methanol had the lowest protective capacity while DMSO the highest. Afterwards, two different thawing rates (1 min at 5 °C; and 25 s at 10 °C) were tested using only 10% DMSO and 10% propanediol. Both for the DMSO and propanediol, there were no significant differences (p > 0.05) between the two thawing rates. The best results were obtained using 10% DMSO. Finally, the fertilization capacity of cryopreserved sperm (10% DMSO and thawed at 5 °C for 1 min) was tested against fresh sperm using two spermatozoa:egg ratios and 4 h gametes contact time. The ratio of eggs with normal cell cleavage, abnormal cleavage or undeveloped were counted at the 2–4 cell stage. Cryopreserved sperm showed lower fertilization capacity at a concentration of 5 × 104 spermatozoa:egg compared with fresh sperm (p < 0.001). At a concentration of 5 × 105 spermatozoa:egg, similar fertilizations rates to the fresh sperm were obtained. The presence of the cryoprotectant DMSO during the 4 h contact time did not affect the fertilization rate or the percentage of embryos with abnormal cleavage (p > 0.05). To cryopreserve spotted wolffish sperm it is recommended to use 10% DMSO, loaded in 0.5 mL straws, freeze at a height between 4.5 (−14.05 °C/min) and 7.5 cm (−5.9 °C/min) from liquid nitrogen for 10 min and thaw for 1 min at 5 °C (177.9 °C/min). In vitro fertilization with cryopreserved sperm should be performed with a concentration of at least 5 × 105 spermatozoa per egg. • The most efficient cryoprotectant for spotted wolffish is 10% DMSO. • The best freezing and thawing conditions are 4.5 or 7.5 cm from LN 2 and 1 min at 5 °C. • For fertilization, 5 × 105 spermatozoa:egg of cryopreserved sperm should be used. [ABSTRACT FROM AUTHOR]

Megabalanus azoricus giant barnacles are the most traditional seafood of the Azores archipelago (NE Atlantic). This valuable commercial species has been highly exploited in the past and it is considered one of the key species for the development of aquaculture in the region. Despite the importance for conservation and aquaculture there is still a lack of basic information about M. azoricus genetic diversity and population structure. Here we used seven microsatellites markers to analyse 300 samples collected at six out of nine islands of the Azores archipelago, including also different locations from a single island, to provide information on the scale of genetic diversity and population structure of this species. Parameters like heterozygosity, allelic richness and effective number of alleles indicated a high genetic diversity and variability among islands. Pairwise comparisons and PCoA analysis on F ST and Jost's D EST showed significant and evident differentiation among sampling locations. Additionally, AMOVA allocates a small (6.02%) but statistically significant portion of the variance to the among Island level revealing also a weak resolution (1.87%) at finer scale. Additionally Monte Carlo resampling methods indicated the most likely sources of the recruits were the local or adjacent populations. Genetic risks associated with the giant barnacle potential production scheme should be taken into account in a future management plan delimiting, as precautionary measure, this culture at a single island or at groups of islands here identified. Moreover a monitoring strategy should be implemented with the aim to evaluate possible changes in genetic parameters of native populations. [ABSTRACT FROM AUTHOR]

Evidence is presented supporting the technical and economic possibilities of giant barnacle Austromegabalanuspsittacus (Molina, 1782) culture, one of the main alternatives for diversifying aquaculture in Chile. Spat collection from the wild varied between different sites in the north and south of the country and according to type of artificial collector. Growth also varied between sites (greater in the north), technological systems (greater in tubular systems) and depths (greater at 4 m). Average commercial size in the national market was reached over a period between 18 and 24 months. A long-line can produce between 7 to 10 gross ton during this period, therefore average annual fisheries production can be reached with only 10 to 30 long-lines, in an area of 1 to 3 ha. There is demand for this resource in the external market, particularly in the Japanese market, either as product similar to "fujit subo" (Balanus rostratus), or as a new resource; the relationship between production costs and price determines that giant barnacle culture has commercial potential. Economic indicators for cultured giant barnacle were as follows: net present value (NPV): US$ 490,000; internal rate of return (IRR): 32%; discounted payback period (DPBP): 4 years. Results obtained suggest the natural bank repopulation option, and the development of mass cultures. Giant barnacle culture is based on biological characteristics that differentiate it from other crustaceans species, as well as simple and economic production technologies and favourable economic projections on external markets.Se presentan evidencias de las posibilidades técnicas y económicas del cultivo del cirripedio gigante o "picoroco", Austromegabalanus psittacus (Molina, 1782). Esta especie es una de las principales alternativas para la diversificación de la acuicultura en Chile. La captación de semilla desde el ambiente varió entre distintos sitios del norte y sur del país y según el tipo de colector artificial. El crecimiento también varió entre localidades (mayor en el norte del país), el tipo de sistema (mayor en sistemas tubulares) y profundidad (mayor a 4 m). La talla comercial promedio del mercado nacional se alcanzó entre 18 y 24 meses. Un long-line puede producir entre 7 y 10 ton brutas en ese periodo, por lo que la producción promedio anual por pesquería se puede alcanzar con sólo 10 a 30 long-lines, en un área de 1 a 3 ha. Existe demanda de este recurso en el mercado externo particularmente en el mercado japonés sea como símil del "fujit subo" (Balanus rostratus) o como recurso nuevo; las relaciones de costos de producción y precios indican que tienen potencialidades en cultivos comerciales. Los indicadores económicos para el picoroco congelado proveniente de cultivo fueron los siguientes: el valor actualizado neto (VAN) es de U$490.000; la tasa interna de retorno (TIR) es de 32% y el periodo de recuperación (PR) es de cuatro anos. Los resultados obtenidos sugieren la opción de repoblamiento de bancos naturales y también para el desarrollo de cultivos masivos. El cultivo del picoroco se basa en características biológicas que lo diferencian de otras especies de crustáceos, además de tecnologías de producción sencillas y baratas y sus proyecciones económicas en mercados externos.

The aim of this review is to provide an update of Seriola spp. farming in the world, excluding yellowtail (S. quinqueradiata), and to identify strengths and weaknesses of these species as candidates for aquaculture diversification in different areas of the world. Farmed Seriola species other than yellowtail are yellowtail kingfish (S. lalandi) in Japan and Australia, longfin yellowtail (S. rivoliana) in the United States, greater amberjack (S. dumerili) in Japan, the Mediterranean and more recently Vietnam, and Pacific yellowtail (S. mazatlana) in North and Central America. Candidate countries for Seriola spp. farming development are China (although there are no published production statistics to date), New Zealand and the Canary Islands. The main bottlenecks for further expansion of Seriola spp. farming appear to be disease impact, lack of genetic improvement programs, and incomplete knowledge of nutrient requirements. Extensive experience from Japan, where the success of Seriola spp. farming has been based on an integrated system between producer associations, research institutes and central government, it is clear that the aforementioned technical bottlenecks need to be addressed within a framework of medium-term public policies supporting aquaculture development. [ABSTRACT FROM AUTHOR]

Evidence is presented supporting the technical and economic possibilities of giant barnacle Austromegabalanus psittacus (Molina, 1782) culture, one of the main alternatives for diversifying aquaculture in Chile. Spat collection from the wild varied between different sites in the north and south of the country and according to type of artificial collector. Growth also varied between sites (greater in the north), technological systems (greater in tubular systems) and depths (greater at 4 m). Average commercial size in the national market was reached over a period between 18 and 24 months. A long-line can produce between 7 to 10 gross ton during this period, therefore average annual fisheries production can be reached with only 10 to 30 longlines, in an area of 1 to 3 ha. There is demand for this resource in the external market, particularly in the Japanese market, either as product similar to "fujit subo" (Balanus rostratus), or as a new resource; the relationship between production costs and price determines that giant barnacle culture has commercial potential. Economic indicators for cultured giant barnacle were as follows: net present value (NPV): US$ 490,000; internal rate of return (IRR): 32%; discounted payback period (DPBP): 4 years. Results obtained suggest the natural bank repopulation option, and the development of mass cultures. Giant barnacle culture is based on biological characteristics that differentiate it from other crustaceans species, as well as simple and economic production technologies and favourable economic projections on external markets. [ABSTRACT FROM AUTHOR]

The croaker Cilus gilberti is an important coastal food fish in Chile and Peru, and is being considered as a target marine species for diversification of Chilean aquaculture. In order to optimize culture, responses to density and potential environmental rearing conditions must be examined. Stocking density (SD) is an important factor for cultivation-related economic viability, because inappropriate SD is frequently associated with an increase of size heterogeneity, modification of social interactions and reduction of flesh quality. In addition, drastic decreases in dissolved oxygen are one of the major recurrent environmental stress factors in the area of choice for C. gilberti farming in the north of Chile, thus studies on responses to hypoxia and their associations with SD are required. Therefore, in this study, C. gilberti juveniles prior to stocking into grow-out pens were maintained for 120 days at three different stocking densities: 15 kg/m3 (LSD), 25 kg/m3 (MSD) and 35 kg/m3 (HSD), and then exposed to an acute hypoxia event. Biometric parameters, flesh quality, blood and liver biochemical parameters, and molecular markers of growth performance and stress responses were analyzed. Surprisingly, the highest body weight gain occurred in fish held at the highest density. In terms of growth-related genes, levels of growth hormone mRNA were not different between stocking densities, but liver insulin-like growth factor 1 (IGF-1) mRNA levels increased with SD and were the highest in the HSD group. There were no differences in flesh proximate composition. Similarly, glucose, lactate and HSP70 levels measured to assess chronic stress were not different among densities. There was a notable increase in lactate levels of fish in the HSD group in response to acute hypoxia, which suggests a greater reliance on anaerobic glycolysis by this group. In conclusion, results suggest that C. gilberti juveniles tolerate high stocking densities (at least 35 kg/m3) without generating chronic stress or decreasing their capacity to respond to acute hypoxia; and high SD would be preferable due to better growth. Although present results are promising, further research is needed to continue with the standardization of the SD that will allow the best productive yield of this new fish species for Chilean aquaculture. • C. gilberti growth and IGF-1 mRNA levels increased with stocking density. • Stocking density did not affect flesh proximate composition. • High stocking density did not induce physiological chronic stress response. • High stocking density did not affect the capacity to respond to acute hypoxia. • C. gilberti juveniles can be maintained at high stocking in extensive pond systems. [ABSTRACT FROM AUTHOR]

Eight different experimental substrates were tested on Paracentrotus lividus competent larvae in order to evaluate their potential for inducing metamorphosis and enhance survival after recruitment. Two benthic diatoms species, Nitzschia laevis (NL) and Halamphora coffeaeformis (HC), were selected according to their capacity to adhere and to form strong biofilms. They were tested in monocultures and in a mixed biofilm (MIX) that was also tried in combination with Gamma-Aminobutyric Acid, involved in triggering some invertebrate metamorphosis (MIX + GABA). Histamine (HIS) was also used as a treatment according to the high metamorphosis rates that have been recorded for this compound on other sea urchin species. Finally, a natural microphytobenthic biofilm (NATURAL) and oyster shells particles colonized by epiphytic diatoms (SHELL) were sampled from the mud of a refining oyster pond. Batches of 21 days-old larvae were placed on each experimental substrate and their effect was compared to a negative control of filtered sea water (without any treatment; FSW). Metamorphosis rate was daily recorded in each treatment. The sea urchin larvae on substrates NL, NATURAL, GABA + MIX and SHELL showed significantly higher metamorphosis rates than larvae on the other treatments (P < 0.001), reaching more than 90% in 72 h. Survival rate was assessed at 10 days post-metamorphosis in these four treatments. No difference was observed between them in terms of metamorphosis rate or survival rate (more than 60% for the four experimental substrates). Results demonstrate that the transition from planktonic larvae to benthic juvenile could be promoted through diatom-based biofilms. These substrates represent efficient metamorphosis inducers for P. lividus larviculture but we suggest to use preferably N. laevis biofilms in order to promote practical and safe solutions for farmers. • The study aims to choose substrates of easy and cheap application for sea urchin recruitment. • Eight different substrates have been tested to study their effect on metamorphosis and post-settlement survival rates. • Diatoms-based biofilms sampled from oyster ponds are appropriate substrates, enhancing metamorphosis and survival rates. • We preferably suggest the use of Nitzschia laevis as its culture allow farmers to implement quality controls. [ABSTRACT FROM AUTHOR]