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1.
Int J Mol Sci ; 22(9)2021 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-33925039

RESUMO

The synthesis of environmentally friendly antimicrobial polymeric coatings, especially in the case of aquaculture, that inhibit the growth of bio-deposits is a very important issue that will contribute to the cost reduction of nets' cleaning process as well as the protection of the submarine wealth from the biostatic substances used so far. In the present work, the antimicrobial polymers P(SSAmC16-co-VBCHAMx) and the terpolymer P(SSAmC16w-co-VBCHAMx-co-GMAy) were synthesized, bearing quaternary ammonium compounds, electrostatically bound and covalently attached at the same polymer chain. The combination of the two types is of particular importance, as it can provide effective antimicrobial polymeric materials with self-polishing capabilities as a result of the released nature of the antimicrobial, in combination with the permanent local action of the immobilized species. The cross-linking reaction of the terpolymer P(SSAmC16w-co-VBCHAMx-co-GMAy) with the homopolymer polyacrylic acid (PAA) was tested at 120 °C in terms of the equivalent ratio between epoxy and carboxyl groups. The synthesized polymers were further used for the coating of aquaculture nets and tested in terms of antifouling efficiency in lab and scale-up conditions. Uncoated nets were also used in all applications for comparison reasons. The coated nets performed efficiently for 35 days in lab-scale and 66 days in scale-up conditions, showing a high antifouling activity in both fields compared to the uncoated nets.


Assuntos
Anti-Infecciosos/síntese química , Anti-Infecciosos/farmacologia , Incrustação Biológica/prevenção & controle , Anti-Infecciosos/química , Aquicultura/métodos , Reagentes para Ligações Cruzadas , Química Verde/métodos , Espectroscopia de Ressonância Magnética , Polímeros/síntese química , Polímeros/química , Compostos de Amônio Quaternário/síntese química , Compostos de Amônio Quaternário/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Eletricidade Estática , Propriedades de Superfície
2.
Molecules ; 26(6)2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33805599

RESUMO

Marine feed ingredients derived from cephalopods (e.g., squid) and crustaceans (e.g., krill) are commercially used to improve the palatability of shrimp diets. Increase in global demand for shrimps has resulted in overfishing of these marine organisms and is a matter of concern. Insect protein hydrolysate could be a sustainable alternative for the possible replacement of these marine feed ingredients. During this study, four formulations: diet A (control: not containing any palatability enhancer), diet B (containing squid meal and krill oil), diet C (containing 1% insect protein hydrolysate), and diet D (containing 2% insect protein hydrolysate) were tested for (1) time required by first subject to begin feeding (time to strike) and (2) palatability in Litopenaeus vannamei. Additionally, the chemical composition of all four diet formulations was also analyzed. Results indicate that all diets had similar crude composition. The major essential amino acids in all diets were leucine and lysine, whereas eicosapentaenoic acid was the major omega-3 fatty acid in all diets. There were no significant differences between the mean time to strike for all the tested formulations. Palatability of tested formulations was found in the following order: diet D > diet C > diet B = diet A (p < 0.05), indicating that addition of squid meal and krill oil has no effect on palatability in comparison to control, whereas inclusion of insect protein hydrolysates significantly improves the palatability of formulations. Palatability enhancement potential of insect protein hydrolysate could be attributed to the high free amino acid content and water solubility in comparison to squid meal.


Assuntos
Ração Animal/análise , Dípteros/química , Proteínas de Insetos/química , Penaeidae/fisiologia , Aminoácidos Essenciais/análise , Animais , Aquicultura/métodos , Proteínas de Artrópodes/química , Conservação dos Recursos Naturais , Decapodiformes/química , Dieta , Proteínas na Dieta/química , Euphausiacea/química , Preferências Alimentares , Humanos , Larva/química , Penaeidae/crescimento & desenvolvimento , Hidrolisados de Proteína/química , Solubilidade
3.
Molecules ; 26(5)2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33671085

RESUMO

Seaweeds have a long history of use as food, as flavouring agents, and find use in traditional folk medicine. Seaweed products range from food, feed, and dietary supplements to pharmaceuticals, and from bioenergy intermediates to materials. At present, 98% of the seaweed required by the seaweed industry is provided by five genera and only ten species. The two brown kelp seaweeds Laminaria digitata, a native Irish species, and Macrocystis pyrifera, a native New Zealand species, are not included in these eleven species, although they have been used as dietary supplements and as animal and fish feed. The properties associated with the polysaccharides and proteins from these two species have resulted in increased interest in them, enabling their use as functional foods. Improvements and optimisations in aquaculture methods and bioproduct extractions are essential to realise the commercial potential of these seaweeds. Recent advances in optimising these processes are outlined in this review, as well as potential future applications of L. digitata and, to a greater extent, M. pyrifera which, to date, has been predominately only wild-harvested. These include bio-refinery processing to produce ingredients for nutricosmetics, functional foods, cosmeceuticals, and bioplastics. Areas that currently limit the commercial potential of these two species are highlighted.


Assuntos
Aquicultura/métodos , Misturas Complexas/química , Laminaria/química , Macrocystis/química , Alga Marinha/química , Animais , Suplementos Nutricionais , Europa (Continente) , Alimentos , Humanos , Legislação como Assunto , Preparações Farmacêuticas , Polissacarídeos/química , Proteínas/química , Controle Social Formal , Estados Unidos
4.
Appl Environ Microbiol ; 87(10)2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33674441

RESUMO

Vibrio coralliilyticus and Vibrio tubiashii are pathogens responsible for high larval oyster mortality rates in shellfish hatcheries. Bacteriophage therapy was evaluated to determine its potential to remediate these mortalities. Sixteen phages against V. coralliilyticus and V. tubiashii were isolated and characterized from Hawaiian seawater. Fourteen isolates were members of the Myoviridae family, and two were members of the Siphoviridae In proof-of-principle trials, a cocktail of five phages reduced mortalities of larval Eastern oysters (Crassostrea virginica) and Pacific oysters (Crassostrea gigas) by up to 91% 6 days after challenge with lethal doses of V. coralliilyticus Larval survival depended on the oyster species, the quantities of phages and vibrios applied, and the species and strain of Vibrio A later-generation cocktail, designated VCP300, was formulated with three lytic phages subsequently named Vibrio phages vB_VcorM-GR7B, vB_VcorM-GR11A, and vB_VcorM-GR28A (abbreviated 7B, 11A, and 28A, respectively). Together, these three phages displayed host specificity toward eight V. coralliilyticus strains and a V. tubiashii strain. Larval C. gigas mortalities from V. coralliilyticus strains RE98 and OCN008 were significantly reduced by >90% (P < 0.0001) over 6 days with phage treatment compared to those of untreated controls. Genomic sequencing of phages 7B, 11A, and 28A revealed 207,758-, 194,800-, and 154,046-bp linear DNA genomes, respectively, with the latter showing 92% similarity to V. coralliilyticus phage YC, a strain from the Great Barrier Reef, Australia. Phage 7B and 11A genomes showed little similarity to phages in the NCBI database. This study demonstrates the promising potential for phage therapy to reduce larval oyster mortalities in oyster hatcheries.IMPORTANCE Shellfish hatcheries encounter episodic outbreaks of larval oyster mortalities, jeopardizing the economic stability of hatcheries and the commercial shellfish industry. Shellfish pathogens like Vibrio coralliilyticus and Vibrio tubiashii have been recognized as major contributors of larval oyster mortalities in U.S. East and West Coast hatcheries for many years. This study isolated, identified, and characterized bacteriophages against these Vibrio species and demonstrated their ability to reduce mortalities from V. coralliilyticus in larval Pacific oysters and from both V. coralliilyticus and V. tubiashii in larval Eastern oysters. Phage therapy offers a promising approach for stimulating hatchery production to ensure the well-being of hatcheries and the commercial oyster trade.


Assuntos
Bacteriófagos , Crassostrea/microbiologia , Larva/microbiologia , Terapia por Fagos , Vibrioses/terapia , Vibrio/virologia , Animais , Aquicultura/métodos , Bacteriófagos/genética , Bacteriófagos/isolamento & purificação , Mortalidade
5.
J Fish Dis ; 44(4): 359-370, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33559228

RESUMO

Aquaculture is the fastest growing food-production sector and is vital to food security, habitat restoration and endangered species conservation. One of the continued challenges to the industry is our ability to manage aquatic disease agents that can rapidly decimate operations and are a constant threat to sustainability. Such threats also evolve as microbes acquire resistance and/or new pathogens emerge. The advent of nanotechnology has transformed our approach to fisheries disease management with advances in water disinfection, food conversion, fish health and management systems. In this review, several nano-enabled technology successes will be discussed as they relate to the challenges associated with disease management in the aquaculture sector, with a particular focus on fishes. Future perspectives on how nanotechnology can offer functional approaches for improving disinfection and innovating at the practical space of early warning systems will be discussed. Finally, the importance of "safety by design" approaches to the development of novel commercial nano-enabled products will be emphasized.


Assuntos
Aquicultura/métodos , Doenças dos Peixes/prevenção & controle , Peixes , Nanotecnologia/métodos , Animais
6.
Methods Mol Biol ; 2273: 263-278, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33604860

RESUMO

Tissue engineering is an elegant tool to create organs in vitro, that can help obviate the lack of organ donors in transplantation medicine and provide the opportunity of studying complex biological systems in vitro, thereby reducing the need for animal experiments. Artificial intestine models are at the core of Fish-AI, an EU FET-Open research project dedicated to the development of a 3D in vitro platform that is intended to enable the aquaculture feed industry to predict the nutritional and health value of alternative feed sources accurately and efficiently.At present, it is impossible to infer the health and nutrition value through the chemical characterization of any given feed. Therefore, each new feed must be tested through in vivo growth trials. The procedure is lengthy, expensive and requires the use of many animals. Furthermore, although this process allows for a precise evaluation of the final effect of each feed, it does not improve our basic knowledge of the cellular and molecular mechanisms determining such end-results. In turn, this lack of mechanistic knowledge severely limits the capacity to understand and predict the biological value of a single raw material and of their different combinations.The protocol described herein allows to develop the two main components essential to produce a functional platform for the efficient and reliable screening of feeds that the feed industry is currently developing for improving their health and nutritional value. It is here applied to the Rainbow Trout, but it can be fruitfully used to many other fish species.


Assuntos
Técnicas de Cultura de Células/métodos , Gelatina/química , Mucosa Intestinal/citologia , Oncorhynchus mykiss , Tecidos Suporte/química , Acrilamidas/química , Ração Animal/análise , Animais , Aquicultura/métodos , Materiais Biocompatíveis/química , Separação Celular/métodos , Células Cultivadas , Norbornanos/química , Oncorhynchus mykiss/crescimento & desenvolvimento
7.
Ecotoxicol Environ Saf ; 208: 111617, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396137

RESUMO

Nitrate (NO3-), a potential toxic nitrogenous compound to aquatic animals, is distributed in aquatic ecosystems worldwide. The aim of this study was to investigate the effects of different NO3- levels on growth performance, health status, and endocrine function of juvenile turbot (Scophthalmus maximus) in recirculating aquaculture systems (RAS). Fish were exposed to 0 mg/L (control, CK), 50 mg/L (low nitrate, LN), 200 mg/L (medium nitrate, MN), and 400 mg/L (high nitrate, HN) NO3-N for 60 d in experimental RAS. Cumulative survival (CS) was significantly decreased with increasing NO3- levels in LN, MN, and HN. The lowest CS was 35% in the HN group. Growth parameters, including absolute growth rate, specific growth rate, and feed conversion rate, were significantly different in HN compared with that in the CK. Histological survey of gills and liver revealed dose-dependent histopathological damage induced by NO3- exposure and significant differences in glutamate pyruvate transaminase and glutamate oxalate transaminase in MN and HN compared with that in the CK. The hepatosomatic index in HN was significantly higher than that in the CK. Additionally, NO3- significantly increased bioaccumulation in plasma in LN, MN, and HN compared to that in the CK. Significant decreases in hemoglobin and increases in methemoglobin levels indicated reduced oxygen-carrying capacity in HN. Additionally, qRT-PCR and enzyme-linked immunosorbent assay (ELISA) were developed to investigate key biomarkers involved in the GH/IGF-1, HPT, and HPI axes. Compared with that in the CK, the abundance of GH, GHRb, and IGF-1 was significantly lower in HN, whereas GHRa did not differ between treatments. The plasma T3 level significantly decreased in LN, MN, and HN and T4 significantly decreased in HN. The CRH, ACTH, and plasma cortisol levels were significantly upregulated in HN compared with that in the CK. We conclude that elevated NO3- exposure leads to growth retardation, impaired health status, and endocrine disorders in turbot and the NO3- level for juvenile turbot culture should not exceed 50 mg/L NO3-N in RAS. Our findings indicate that endocrine dysfunction of the GH/IGF-1, HPT, and HPI axes might be responsible for growth inhibition induced by NO3- exposure.


Assuntos
Aquicultura/métodos , Sistema Endócrino/efeitos dos fármacos , Linguados/crescimento & desenvolvimento , Nitratos/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Ecossistema , Sistema Endócrino/metabolismo , Brânquias/efeitos dos fármacos , Brânquias/patologia , Nível de Saúde , Fígado/efeitos dos fármacos , Fígado/patologia , Alimentos Marinhos , Hormônios Tireóideos/metabolismo
8.
Mol Biol Rep ; 48(1): 989-995, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33393004

RESUMO

Rainbow trout (Onchorhynchus mykiss) is one of the most important freshwater aquaculture fish in Iran. It is necessary to develop available molecular marker such as SNPs, which represent a useful tool in detecting adaptive signals in populations and also parentage assignment for O. mykiss. Genetic architecture of broodstock populations is important for breeding programs, as it enables decisions on broodstock screening and genomic selection. In this study, 52 novel single nucleotide polymorphism (SNP) markers for O. mykiss were discovered and validated based on transcriptome sequencing, by means of paired-end sequencing in an Illumina HiSeq 2500 platform. The SNPs were identified through liver transcriptome sequencing from fifteen samples. The observed and expected heterozygosities ranged from 0.177 to 1.000 and 0.239 to 0.638, respectively. The minimum allele frequency (MAF) ranged from 0.166 to 0.489. Among these SNP loci, twenty-two loci showed significant departures from the Hardy-Weinberg equilibrium after Bonferroni correction (p < 0.05) and significant linkage disequilibrium was found. The SNP markers identified in this research could be useful for novel studies, such as those related to associations between high-resolution molecular markers and quantitative traits studies. Moreover, these SNP markers would be used in genetic studies helping economic performance improvement and management of this species.


Assuntos
Marcadores Genéticos , Oncorhynchus mykiss/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Transcriptoma , Alelos , Animais , Aquicultura/métodos , Feminino , Frequência do Gene , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Irã (Geográfico) , Desequilíbrio de Ligação , Masculino
9.
Fish Shellfish Immunol ; 111: 140-144, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33503475

RESUMO

Innate immunity in arthropods is achieved largely through melanization which is in turn the result of the prophenoloxidase (ProPO) activation cascade; a series of biochemical reactions triggered by the immune identification of pathogen-recognition proteins (PRPs). Within this activation cascade, inactive proPO is cleaved to form the reactive enzyme phenoloxidase (PO). Methods of detecting PO are used to assess an arthropod's ability to respond to immune challenges. These detection assays have been described for some arthropods, especially those of commercial value, but none are available for Euastacus, a genus within the superfamily Parastacoidea. This study is the first step in developing a standardized protocol for the detection and quantification of PO activity in wild or captive Murray crayfish Euastacus armatus. Hemolymph extracts from 49 crayfish were assessed for PO activity using an assay measuring the conversion of l-dopa (3,4-dihydroxy-l-phenylalanine) into dopachrome. Short periods (up to 15 min) out of water did not cause any measurable change in PO activity. Phenoloxidase activity was detected in captive (n = 24, stressed) and wild (n = 25, healthy) crayfish with captive crayfish showing lower levels of PO possibly indicating immunosuppression. The proven protocol is the first of its kind to propose a standardized methodology for the detection and quantification of PO activity in Murray crayfish hemolymph as a means of determining stress.


Assuntos
Aquicultura/métodos , Proteínas de Artrópodes/análise , Astacoidea/enzimologia , Monofenol Mono-Oxigenase/análise , Animais , Feminino , Masculino
10.
J Fish Dis ; 44(6): 711-719, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33493378

RESUMO

Aeromonas salmonicida (As) is a highly heterogeneous bacterial species, and strains' host specificity has been reported. Ballan wrasse (Labrus bergylta Ascanius, 1767) is susceptible to atypical As (aAs) vapA type V and type VI in Scotland and Norway. Identification of the bacterium is achieved by culture and molecular techniques; however, the available methods used to distinguish the As types are costly and time-consuming. This paper describes the development of a PCR and a restriction enzyme assay for the detection of aAs vapA type V and type VI in ballan wrasse, respectively. Type V-specific primers were designed on conserved regions of the vapA gene, and the restriction enzyme assay was performed on the PCR products of the hypervariable region of vapA gene for the detection of type VI isolates. Amplification product was produced for type V (254 bp) and restriction bands (368 and 254 bp) for type VI isolates only. In addition, the assays detected type V and type VI isolates in spiked water samples and type V in diagnostic tissue samples. The assays are fast, specific and cost-effective and can be used as specific diagnostic tools for cleaner fish, to detect infectious divergence strains, and to manage and mitigate aAs disease outbreaks through vaccine development.


Assuntos
Aeromonas salmonicida/isolamento & purificação , Suscetibilidade a Doenças/veterinária , Peixes , Furunculose/diagnóstico , Infecções por Bactérias Gram-Negativas/veterinária , Reação em Cadeia da Polimerase/veterinária , Mapeamento por Restrição/veterinária , Animais , Aquicultura/métodos , Suscetibilidade a Doenças/diagnóstico , Suscetibilidade a Doenças/microbiologia , Furunculose/microbiologia , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por Bactérias Gram-Negativas/microbiologia , Reação em Cadeia da Polimerase/métodos , Mapeamento por Restrição/métodos , Escócia
11.
Gene ; 776: 145351, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33333226

RESUMO

Resolving the temporal community composition of a larvae population can not only further our understanding of the regional species composition but also help us to infer the reproductive times of regional fish taxa, which can have implications on the development of effective monitoring and conservation policies for the regional fish stock. Nevertheless, correctly diagnosing the fish larvae is extremely challenging due to the paucity of diagnostic morphological characters at the species level. Based on daily larval samplings during March and October in 2018, this study combined morphological features with a DNA barcode technique to determine the species composition of fish larvae in the lower Pearl River drainage (LPR) and evaluate the spawning periods of identified species. Due to an absence of reference barcodes for LPR fishes, a DNA barcode library of adult fishes in the LPR was built for 384 individuals representing 78 morphological species. Analyses demonstrated the usability of the barcode library and uncovered many undetected mitochondrial lineages in 12 species. Morphological analyses performed on 81 temporal larval samples revealed 25 morphotypes and assigned 9 morphotypes into the species level. A total of 1624 larvae from 96 temporal larval samples were selected for molecular identification, and high quality barcoding sequences were obtained from 1391 larvae. We accurately assigned 1078 larvae to 37 species using our barcode library and published database. Among the identified species, a critically endangered species, namely, Ochetobius elongatus, and several invasive species were examined, providing a new perspective to assess the stock of regional endangered and invasive species. Furthermore, this study found high species diversity occurred primarily between May and September, and clarified the spawning periods of identified species inferred from the temporal occurrences of larvae. Above all, our study highlights the applicability to fish larval ecology to assist conservation and fishery management efforts.


Assuntos
Aquicultura/métodos , Peixes/genética , Larva/genética , Animais , China , Código de Barras de DNA Taxonômico/métodos , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genética Populacional/métodos , Filogenia , Reprodução/genética , Reprodução/fisiologia , Rios , Especificidade da Espécie
12.
Ecotoxicol Environ Saf ; 209: 111810, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33360217

RESUMO

The number of undesirable environmental impacts of fish feed has been reported widely. Although repeated fish feed exposures are more prospective to occur in water, previous studies were mostly conducted as a single exposure of fish feed. In order to fill these gaps, a 40 days incubator experiment was conducted to explore the effects of fish feed addition scenarios during the lag phase with prometryn on both Microcystis aeruginosa growth and concentrations of nutrients. The maximum algae densities in groups of single exposure were 6.0-26.2% and 8.8-74.4% higher than those in groups of double and triple exposures, respectively (P < 0.05). At the beginning of the experiment, concentrations of nutrients in groups with different feed exposure scenarios were significantly different. The pattern of nutrient limitation showed a transformation from phosphorus limitation to nitrogen limitation generally. Furthermore, the average inhibition rates of algae by prometryn in the case of a single fish feed exposure were 4.6-9.4% lower than those under double exposures, and 22.0-26.8% lower than those under triple exposures (P < 0.05). In addition, algae growth rates have been developed as a function of concentrations of consumed nutrients (R2 = 0.410-0.932). Based on the above results, we concluded that in terms of limiting algae growth multiple low-dosage additions of fish feed were considered as a better addition pattern. By optimizing feed addition scenarios, there is considerable potential to increase the environmental sustainability of aquaculture.


Assuntos
Ração Animal , Herbicidas/toxicidade , Microcystis/efeitos dos fármacos , Prometrina/toxicidade , Animais , Aquicultura/métodos , Peixes , Microcystis/crescimento & desenvolvimento , Nitrogênio/análise , Nutrientes , Fósforo/análise , Estudos Prospectivos , Qualidade da Água
13.
Methods Mol Biol ; 2219: 1-29, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33074531

RESUMO

Cephalochordates (amphioxus) are invertebrate chordates closely related to vertebrates. As they are evolving very slowly, they are proving to be very appropriate for developmental genetics studies aimed at understanding how vertebrates evolved from their invertebrate ancestors. To date, techniques for gene knockdown and overexpression have been developed, but methods for continuous breeding cultures and generating germline mutants have been developed only recently. Here we describe methods for continuous laboratory breeding cultures of the cephalochordate Branchiostoma floridae and the TALEN and Tol2 methods for mutagenesis. Included are strategies for analyzing the mutants and raising successive generations to obtain homozygotes. These methods should be applicable to any warm water species of cephalochordates with a relatively short generation time of 3-4 months and a life span of 3 years or more.


Assuntos
Aquicultura/métodos , Anfioxos/genética , Mutagênese , Ração Animal/análise , Animais , Cruzamento , Feminino , Anfioxos/crescimento & desenvolvimento , Anfioxos/fisiologia , Masculino , Nucleases dos Efetores Semelhantes a Ativadores de Transcrição/genética
14.
Methods Mol Biol ; 2219: 49-68, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33074533

RESUMO

Here we describe methods for (a) collecting starfish during their breeding period; (b) maintaining adults with fully grown gonads in laboratory aquaria; (c) rearing fertilized eggs to brachiolaria larvae, and (d) inducing larvae to metamorphose into juveniles under laboratory conditions. Such protocols should facilitate various analyses of starfish development throughout the entire life cycle of these model organisms.


Assuntos
Asterina/crescimento & desenvolvimento , Animais , Aquicultura/instrumentação , Aquicultura/métodos , Asterina/embriologia , Desenho de Equipamento , Feminino , Larva/crescimento & desenvolvimento , Masculino , Metamorfose Biológica , Oócitos/citologia , Oogênese
15.
PLoS One ; 15(12): e0244607, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382783

RESUMO

With the worldwide demand for tropical penaeid prawn increasing in recent decades, more research on shrimp culture methods is needed to enhance efficiency and profitability for shrimp farmers. The objective of this study was to develop a technique to boost the productivity, feed efficiency, and profitability of the giant tiger prawn (Penaeus monodon). To accomplish this, a novel culture setup was established in which two benthic organisms, a filamentous green alga (Chaetomorpha sp.) and a microsnail (Stenothyra sp.), were propagated together with P. monodon post-larvae during an early culture stage and then offered to shrimp as supplementary live feeds in intensive aquaculture ponds. For the experiment, shrimp post-larvae (density: approximately 33 individuals m-2) were cultured in outdoor concrete ponds (9 × 9 × 1.2 m) under either control (fed only artificial feed, n = 3) or experimental (fed artificial feed and benthic organisms, n = 3) conditions until they reached marketable size (15 weeks). Apparent green algae consumption was 6.81 kg (8.4% green alga to total feed consumption), whereas microsnail consumption was 1.96 kg (2.4% microsnail to total feed consumption). Compared with the control group of giant tiger prawn, the experimental group showed significantly higher productivity (total number of shrimp produced: 118%; total shrimp production: 133%), feed efficiency (feed conversion ratio of artificial shrimp feed: 89%), and profitability (shrimp sales: 139%; balance between shrimp sales and costs: 146%), while labor and financial costs were kept minimal. These results can be explained by the enhanced growth of shrimp at the early stages of culture. The techniques developed in this study will help to advance the efficiency of intensive aquaculture operations for giant tiger prawn and also improve profitability for shrimp farmers.


Assuntos
Ração Animal/análise , Penaeidae/fisiologia , Animais , Aquicultura/métodos , Tamanho Corporal , Clorófitas , Penaeidae/crescimento & desenvolvimento , Caramujos
16.
Bull Environ Contam Toxicol ; 105(5): 705-710, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32979082

RESUMO

Bath treatment pharmaceuticals used to control sea lice infestations in the salmonid industry, such as hydrogen peroxide (H2O2), are released directly into the environment where non-target organisms are at risk of exposure. The aim of this study was to determine the threshold concentrations for mortality of the Northern krill, Meganyctiphanes norvegica, a major component of the north Atlantic marine ecosystem. To assess the lethal effects of H2O2, we carried out a series of 1 h acute toxicity tests and assessed mortality through a 48 h post-exposure period. One-hour exposure to 170 mg/L, corresponding to 10% of the recommended H2O2 treatment, caused 100% mortality and a subsequent acute median-lethal concentration LC50 value of 32.5 mg/L. Increased mortality was observed with time in all exposed groups, resulting in successively lower LC50 values during the post-exposure period. The suggested H2O2 concentrations have the potential of causing negative effects to the Northern krill.


Assuntos
Euphausiacea/efeitos dos fármacos , Peróxido de Hidrogênio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Aquicultura/métodos , Relação Dose-Resposta a Droga , Ecossistema , Euphausiacea/crescimento & desenvolvimento , Dose Letal Mediana , Noruega , Alimentos Marinhos , Análise de Sobrevida , Testes de Toxicidade Aguda
17.
Ecotoxicol Environ Saf ; 204: 111111, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32795703

RESUMO

Bath treatment chemotherapeutants, used to control sea lice infestations in the salmonid aquaculture industry, are released directly into the marine environment around fish farms and pose a serious risk to non-target species, particularly crustaceans. Hydrogen peroxide (H2O2) is the most frequently used bath treatment chemotherapeutant on Norwegian fish farms, however, limited information is available on its toxicity to European lobsters (Homarus gammarus), a commercially important species at risk of exposure due to its distribution overlapping with salmon farm locations. The aim of this study was to investigate the lethal effects of H2O2 on pelagic (stage I-IV) larvae/post-larvae and its sub-lethal effects on the benthic stage V H. gammarus. To assess the lethal effects of H2O2, we carried out a series of 1 h toxicity tests and assessed mortality after a 24 h post-exposure period. Exposure to H2O2 was toxic to all pelagic larval stages tested, with estimated median lethal concentrations (LC50) of 177, 404, 665 and 737 mg/L for stage I, II, III and IV, respectively. These concentrations represent approximately 10, 23, 40 and 43%, of the recommended H2O2 concentrations used for delousing salmon on Norwegian fish farms, respectively. To assess the sub-lethal effects of H2O2 on H. gammarus, stage V juveniles were exposed to H2O2 at concentrations of 85, 170 and 510 mg/L for 1 h and shelter-seeking behaviour and mobility endpoints were assessed. Numerous behavioural parameters including distance travelled to shelter, time to locate shelter and the number of shelter inspections, were negatively affected in lobsters exposed to H2O2 when assessed immediately after the exposure period. However, no differences between control and exposed lobsters were detected after a 24 h post-exposure period. Our results demonstrate that short term exposures to H2O2 are lethal to pelagic H. gammarus life stages and can negatively affect the shelter seeking behaviour of benthic life stages, though these behavioural changes may be short-lived.


Assuntos
Peróxido de Hidrogênio/toxicidade , Nephropidae/fisiologia , Animais , Aquicultura/métodos , Comportamento Exploratório , Pesqueiros , Larva/efeitos dos fármacos , Dose Letal Mediana , Nephropidae/efeitos dos fármacos , Noruega , Salmão , Testes de Toxicidade
18.
PLoS One ; 15(8): e0237775, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32813739

RESUMO

Nile tilapia, Oreochromis niloticus is the third most commonly farmed finfish species in the world, accounting for nearly 5% of global aquaculture production. In the past few decades much of the success of this species has been attributed to the development and distribution of Genetically Improved Farmed Tilapia (GIFT). Despite the increasing availability of GIFT, the productivity of small-scale farming remains highly variable, particularly in developing nations. Commercial fish-feed pellets can increase fish farm productivity; however, many small-scale farmers rely on other means of feeding fish due to the high cost and limited availability of commercial fish feed pellets. Therefore, understanding how locally-sourced feeds affect the production of GIFT is an important step towards improving feeding practices, particularly for farmers with low financial capital. This study used stable isotope analysis (SIA) and 16S rRNA gene sequencing to compare the effects of a locally-sourced vegetable-based diet and commercial pellet-based diets on the relative condition, nutrient assimilation patterns and gastrointestinal microbiota of GIFT. GIFT fed a locally-sourced diet were smaller, and in a significantly poorer condition than those fed with commercial fish feeds. SIA showed no differences in dietary carbon between the two diets; however, δ13C, poor fish condition and the abundance of specific bacterial taxa (of such as Fusobacteria) were correlated. SIA revealed that GIFT fed locally-sourced diets that predominantly consisted of vegetables were significantly enriched in δ15N despite a perceived lack of dietary protein. This enrichment suggests that GIFT fed a locally-sourced diet may be supplementing their diet via cannibalism, a behaviour representative of poor farming practice. Overall this study highlights the need to increase the availability of suitable GIFT feeds in developing nations. The development a low-cost feed alternative could improve the success of small-scale GIFT farmers in PNG, increasing both food and income security within the region.


Assuntos
Ração Animal , Animais Geneticamente Modificados/metabolismo , Aquicultura/métodos , Ciclídeos/metabolismo , Microbioma Gastrointestinal/fisiologia , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/microbiologia , Aquicultura/economia , Aquicultura/organização & administração , Canibalismo , Ciclídeos/genética , Ciclídeos/microbiologia , DNA Bacteriano/isolamento & purificação , Suplementos Nutricionais/economia , Eficiência Organizacional/economia , Fazendas/economia , Fazendas/organização & administração , New South Wales , Nutrientes/metabolismo , RNA Ribossômico 16S/genética
19.
J Vis Exp ; (160)2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32628172

RESUMO

Oikopleura dioica is a planktonic chordate with exceptional filter-feeding ability, rapid generation time, conserved early development, and a compact genome. For these reasons, it is considered a useful model organism for marine ecological studies, evolutionary developmental biology, and genomics. As research often requires a steady supply of animal resources, it is useful to establish a reliable, low-maintenance culture system. Here we describe a step-by-step method for establishing an O. dioica culture. We describe how to select potential sampling sites, collection methods, target animal identification, and the set-up of the culturing system. We provide troubleshooting advice based on our own experiences. We also highlight critical factors that help sustain a robust culture system. Although the culture protocol provided here is optimized for O. dioica, we hope our sampling technique and culture setup will inspire new ideas for maintaining other fragile pelagic invertebrates.


Assuntos
Aquicultura/métodos , Urocordados , Animais , Feminino , Masculino
20.
Sci Rep ; 10(1): 12224, 2020 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-32699383

RESUMO

Piscirickettsia salmonis is the causative agent of piscirickettsiosis, a disease with high socio-economic impacts for Chilean salmonid aquaculture. The identification of major environmental reservoirs for P. salmonis has long been ignored. Most microbial life occurs in biofilms, with possible implications in disease outbreaks as pathogen seed banks. Herein, we report on an in vitro analysis of biofilm formation by P. salmonis Psal-103 (LF-89-like genotype) and Psal-104 (EM-90-like genotype), the aim of which was to gain new insights into the ecological role of biofilms using multiple approaches. The cytotoxic response of the salmon head kidney cell line to P. salmonis showed interisolate differences, depending on the source of the bacterial inoculum (biofilm or planktonic). Biofilm formation showed a variable-length lag-phase, which was associated with wider fluctuations in biofilm viability. Interisolate differences in the lag phase emerged regardless of the nutritional content of the medium, but both isolates formed mature biofilms from 288 h onwards. Psal-103 biofilms were sensitive to Atlantic salmon skin mucus during early formation, whereas Psal-104 biofilms were more tolerant. The ability of P. salmonis to form viable and mucus-tolerant biofilms on plastic surfaces in seawater represents a potentially important environmental risk for the persistence and dissemination of piscirickettsiosis.


Assuntos
Biofilmes/crescimento & desenvolvimento , Piscirickettsia/crescimento & desenvolvimento , Infecções por Piscirickettsiaceae/microbiologia , Animais , Aquicultura/métodos , Linhagem Celular , Chile , Doenças dos Peixes/microbiologia , Genótipo , Rim Cefálico/microbiologia , Piscirickettsia/genética , Salmo salar/microbiologia
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