Wild Stocks Research Articles

Use of vegetable raw materials in production of vegetable - berry purees with the set organoleptic, technological properties and nutrition value

An important component of the population’s nutrition is vegetable raw material, including root vegetables. High-quality, standard raw materials are used for fresh sale in retail trade and at catering establishments; they are also laid for winter storage. However, there is a sufficient amount of substandard raw materials - in size, shape, deformation, and violation of integrity. Moreover, such raw materials have a high nutritional value. This paper presents the rationale for the recipe composition of blended types of purees using roots and wild berries. With the help of mathematical modelling, the optimum ratios of the components are determined, at which there is a high correlation between the organoleptic characteristics, technological properties and the content of biologically active substances. The results of the work make it possible to use substandard vegetable raw materials and wild berry stocks rationally. They allow wide use of new types of purees, including its use as semi-finished products for enhancing the nutritional value in the confectionery industry.

Optimal salmon lice treatment threshold and tragedy of the commons in salmon farm networks

The ectoparasite Lepeophtheirus salmonis has for decades plagued salmon aquaculture by decreasing profits and impacting wild salmon stocks. To protect migrating wild salmon stocks and avoid excessive cross-farm infections, authorities require treatments when sea lice level reach a given threshold. The treatment threshold is set to protect wild salmonid stocks but also to avoid costly lice infections on neighboring farms. Here we make a bio-economic estimation of optimal treatment thresholds. We are particularly interested in identifying conflicts between the optimal threshold of the entire system of farms and for the individual farmer. We show that isolated individual farms can maximize profit by operating with a high threshold, while the maximum profit for an entire network of farms occurs with a threshold about 0.1 gravid female lice/salmon. These findings substantiate the Norwegian policy of lowering the lice treatment threshold below 0.5 gravid lice/salmon. The results also demonstrate that too low a treatment threshold results in high treatment rates. The difference between the optimal treatment strategy of individual farmers and that for the total system demonstrates that management of salmon lice infections operates in a tragedy-of-the-commons environment, where individual farmers may have an incentive to disregard legislation at the expense of the others in the network. This means that strong enforcement is needed to achieve optimal management of salmon lice infections.

Genome-Wide Association Study of Growth and Body-Shape-Related Traits in Large Yellow Croaker (Larimichthys crocea) Using ddRAD Sequencing.

Large yellow croaker (Larimichthys crocea) is an economically important marine fish species of China. Due to overfishing and marine pollution, the wild stocks of this croaker have collapsed in the past decades. Meanwhile, the cultured croaker is facing the difficulties of reduced genetic diversity and low growth rate. To explore the molecular markers related to the growth traits of croaker and providing the related SNPs for the marker-assisted selection, we used double-digest restriction-site associated DNA (ddRAD) sequencing to dissect the genetic bases of growth traits in a cultured population and identify the SNPs that associated with important growth traits by GWAS. A total of 220 individuals were genotyped by ddRAD sequencing. After quality control, 27,227 SNPs were identified in 220 samples and used for GWAS analysis. We identified 13 genome-wide significant associated SNPs of growth traits on 8 chromosomes, and the beta P of these SNPs ranged from 0.01 to 0.86. Through the definition of candidate regions and gene annotation, candidate genes related to growth were identified, including important regulators such as fgf18, fgf1, nr3c1, cyp8b1, fabp2, cyp2r1, ppara, and ccm2l. We also identified SNPs and candidate genes that significantly associated with body shape, including bmp7, col1a1, col11a2, and col18a1, which are also economically important traits for large yellow croaker aquaculture. The results provided insights into the genetic basis of growth and body shape in large yellow croaker population and would provide reliable genetic markers for molecular marker-assisted selection in the future. Meanwhile, the result established a basis for our subsequent fine mapping and related gene study.

Behavioural effects in juvenile brown trout in response to parental angling selection

Fishing that selectively captures and removes fish based on their behavioural decisions is predicted to induce evolution towards timid fish stocks. Thus, offspring behaviour should associate with parental vulnerability to angling. We examined phenotypic behavioural variation in juvenile brown trout (Salmo trutta) whose parents, representing a hatchery and a wild stock, were experimentally grouped based on their relative vulnerability to angling. The F1 offspring from highly vulnerable (HV) and low vulnerable (LV) parents were reared in common garden conditions together with a crossbred wild × hatchery reference group and tested for boldness during their first summer. Wild LV juveniles were the shyest of all fish, but not distinctly shyer than wild HV juveniles. Contradictorily, hatchery LV juveniles expressed bolder behaviour than hatchery HV juveniles. We show that angling selection may have transgenerational behavioural effects independently of size variation, but changes in behaviour can manifest differently in fish from different backgrounds. Our results partly support the earlier findings of increased angling-induced timidity in wild populations and thus call for management focus on behavioural effects of fishing.

Dnd shRNA constructs cause altered PGC migration but fail to sterilize

The release or escape of genetically modified fish from confined aquaculture facilities presents a potential risk to wild fish stocks and surrounding ecosystems. Thus, reliable biocontainment methods for aquaculture-relevant species are needed. Since physical barriers are not 100% effective, it is critical to develop reliable genetic-based methods for biocontainment. RNA interference (RNAi) could regulate gene expression and target genes that are essential for fish viability and/or reproduction. One such target gene, deadend (dnd), is required for primordial germ cell (PGC) development, migration and survival. While the use of RNAi technology has been successfully reported in C. elegans, M. musculus, and D. melanogaster, its use in zebrafish (Danio rerio) has been met with variable success. We targeted dnd using two different short-hairpin RNA (shRNA) approaches in zebrafish embryos, namely, 1) CMV-driven or a Gal4/UAS constructs with one double short-hairpin RNA stem-loop design consisting of two different target sites, and 2) CMV-driven to test two separate target sites independently flanked by the 5′ and 3′ sequences of the pri-miR-30e miRNA. The first shRNA strategy did not completely nor consistently abolish PGCs, based on vasa-expression, but low vasa expression was observed in some fish at 6 dpf. In contrast, the second shRNA strategy resulted in reduced and/or ectopic positioning of PGCs based on vasa expression at 2 and 6 dpf. However, neither strategy affected fertility in adult fish.

Ancient cattle genomics, origins, and rapid turnover in the Fertile Crescent.

Genome-wide analysis of 67 ancient Near Eastern cattle, Bos taurus, remains reveals regional variation that has since been obscured by admixture in modern populations. Comparisons of genomes of early domestic cattle to their aurochs progenitors identify diverse origins with separate introgressions of wild stock. A later region-wide Bronze Age shift indicates rapid and widespread introgression of zebu, Bos indicus, from the Indus Valley. This process was likely stimulated at the onset of the current geological age, ~4.2 thousand years ago, by a widespread multicentury drought. In contrast to genome-wide admixture, mitochondrial DNA stasis supports that this introgression was male-driven, suggesting that selection of arid-adapted zebu bulls enhanced herd survival. This human-mediated migration of zebu-derived genetics has continued through millennia, altering tropical herding on each continent.

The complete mitochondrial genome of black sea cucumber Holothuria leucospilota (Aspidochirotida holothuriidae)

The black sea cucumber, Holothuria leucospilota, is an ecologically and economically important holothuroid in China due to broader environmental adaptation and valuable pharmacological compounds. However, the wild stocks of H. leucospilota, have been declining steadily due to overexploitation in recent years. The stock enhancement programme has become an increasingly important priority. In this study, we report the complete mitochondrial genome of H. leucospilota. The mitogenome has 15,839 base pairs (57.6% A + T content) and made up of total of 37 genes (13 protein-coding, 22 transfer RNAs and 2 ribosomal RNAs), and a putative control region. The complete mitogenomes of H. leucospilota will provide useful genetic information for future conservation and management of this valuable and vulnerable species.

Release of hatchery-reared brown trout (Salmo trutta) as a threat to wild populations? A case study from Austria

In spite of growing evidence pointing to ecological and genetic risks to wild fish populations, artificial propagation and stocking remain common practices for recreational fishery management. Moreover, even a cursory level of monitoring and evaluation of these risks is neglected, especially where fisheries are managed by private entities. Against this backdrop and with the goal of establishing a more integrated system of ecosystem-based management, this study aims to identify potential threats from the current practices and patterns of brown trout management in Austria. We surveyed 26 private brown trout hatchery operations in three Austrian provinces to examine and categorize the practices in the production of brown trout for stocking. Specifically, we examined the rearing practices and the “trading networks” among trout farmers for characteristics such as rearing history, operating principles, broodstock origins and maintenance, and output figures. Several risk-associated practices emerged, including introduction of brood from divergent lineages outside of Austrian watersheds, translocation and mixing of fish across major watersheds within Austria, and reinforced domestication across multiple generations of captivity. These practices jeopardize native populations by disrupting local adaptations resulting from mixing of native and non-native lineages, reducing genetic diversity within lineages from population bottlenecks, and lowering success of wild populations from domestication selection within the hatchery environment. The findings, which identify threats rather than directly measure impacts, are discussed within the context of concerns on the role of conserving intraspecific diversity for native brown trout fisheries. We conclude by suggesting the integration of ecological and genetic principles into propagation and stocking practices to achieve fishery management strategies more compatible with maintaining natural diversity and adaptive potential of brown trout in Austria.

Prevalence and genotypes of infectious salmon anaemia virus (ISAV) in returning wild Atlantic salmon (Salmo salar L.) in northern Norway.

Prevalence and genotypes of infectious salmon anaemia virus (ISAV) in returning wild Atlantic salmon (Salmo salar L.) in northern Norway.

Bivalves boost biodiversity

Bivalves boost biodiversity

Endoscopy and Cannulation as Non-Invasive Tools to Identify Sex and Monitor Reproductive Development in Arapaima gigas

The lack of tools for sex identification and assessment of gonadal development are hindering our ability to study the reproductive dysfunction of Arapaima gigas in captivity. This study initially aimed to validate a non-surgical endoscopy procedure to identify sex in juveniles and assess stage of ovary development in female broodstock under field operational conditions. Cannulation, assisted through the description of the genital anatomy, made ovarian biopsy possible to describe oocyte development from primary growth to pre-ovulation, providing a first classification scheme for oogenesis in the species including description of the micropyle morphology using scanning electron microscopy. Cannulation was also successfully performed without endoscopic guidance, which allowed monitoring of ovarian development along the reproductive season together with profiling of plasma sex steroids (17β-estradiol [E2] and 11-ketotestosterone [11-KT] in females and males, respectively). The monitoring of our study population showed females paired with males in earthen ponds sexually matured and reached oocyte maturation during the spawning season. However, since no spawning was recorded, eggs had either been resorbed or released and not fertilized by the male. Plasma E2 levels remained high in females, as expected in an asynchronous species during the spawning season with multiple batches of oocytes being recruited. Plasma 11-KT showed a tendency to decrease, suggesting a male reproductive dysfunction or the end of the reproductive season with a lack of synchronization between sexes. In conclusion, endoscopy and cannulation are tools that can be promptly applied to aid sex identification, assessment of reproductive function, and overall broodstock management in wild and captive stocks. These tools will greatly help future studies looking at the effects of environmental, social, and hormonal cues on reproductive development with the aim of developing a spawning induction protocol for the species.

Transcriptome sequencing and de novo analysis of the northern snakehead, Ophiocephalus argus

Northern snakehead, Ophiocephalus argus Cantor, is an endemic freshwater fish in China. However, wild stocks of O. argus are dwindling sharply. Further, water conservancy projects, environmental pollution and human activities have caused the decrease of wild stocks, which has attracted much attention. Here, we have investigated the genomic information of O. argus using IlluminaHiseq 4000 sequencing. The transcriptomes of O. argus were sequenced by Illumina technology. A total of 67,564 sequences from 79,500,964 paired-end reads were generated, 33,710 unigenes were annotated based on protein databases (NCBI nonredundant (NR) databases). In total, 7182 unigenes had the clusters of orthologous group (COG) classifications, 33,710 unigenes were assigned to 59 gene ontology (GO) terms. Further, a total of 21,464 simple sequence repeats (SSRs) from 67,564 unigenes and 113,518 single nucleotide polymorphism (SNP) sites among 335 Mclean reads were yielded for O. argus based on a transcriptome-wide search. The new transcriptome data which is presented in this study for O. argus will provide valuable information for gene discovery and downstream applications, such as phylogenetic analysis, gene-expression profiling and identification of genetic markers (SSRs andSNP).

The Ganges basin fish Cirrhinus mrigala (Cypriniformes: Cyprinidae): detection of wild populations stock structure with landmark morphometry

Cirrhinus mrigala es una carpa originaria del sistema fluvial del rio Ganges al norte de India, de cual no hay informacion sobre la variacion morfometrica de sus poblaciones naturales en esta cuenca. Por lo tanto, para promover la optimizacion de su manejo, se evaluo la estructura poblacional usando morfometria basada en puntos de referencia de C. mrigala. En total se midieron 381 individuos de C. mrigala, recolectados en 10 puntos de 10 rios de la cuenca del Ganges. Se utilizaron 12-puntos de referencia de sistema de redes truss para generar 66 variables morfometricas, de donde se excluyo la longitud estandar y se utilizaron 65 variables. Las medidas transformadas se utilizaron para un analisis de varianza univariado, analisis de componentes principales y analisis de funcion discriminante. El analisis de varianza mostro diferencias en todos los 65 caracteres morfometricos estudiados. Se extrajeron ocho componentes principales de los 65 caracteres, que suman el 94.1 % de la variacion. El analisis de funcion discriminante de las 65 variables produjo ocho variables discriminantes que contribuyeron en la varianza a nivel general. La primera funcion discriminante represento 37.9 %, mientras que la segunda 23.5 % de la variacion entre grupos. En el analisis de funcion discriminante, 39.1 % de lo agrupado por validacion cruzada fue correctamente clasificado en la asignacion general de individuos, lo que indica baja diferenciacion entre las poblaciones, lo que puede ser un bajo aislamiento de las poblaciones para las medidas morfometricas. Otra posible razon para la baja diferenciacion morfometrica es la existencia de un ancestro comun en el periodo prehistorico y la migracion de individuos entre rios. En el futuro, la aplicacion de marcadores geneticos moleculares junto con estudios morfometricos sera un metodo efectivo para examinar el componente genetico de la relacion fenotipica entre areas geograficas y facilitar el desarrollo de recomendaciones de manejo.

DETERMINE THE COMPETENCE OF DIFFERENT FRESH DIETS TO IMPROVE THE SPERMATOPHORE SUPERIORITY OF GIANT BLACK TIGER SHRIMP, PENAEUS MONODON (FABRICIUS, 1798)

The intention of the present study was to assess the effect of fresh natural food on spermatophore quality and analysis by the way of sperm weight, count, viability as well as the proximate analysis of offered food and shrimp brood stock. The experiment was carried out with the three following treatments; fresh squid, polychaete and beef liver up to 5 weeks. All parameters were measured by the starting of 3 rd week (15 days) and the end of the (35 days) of the experiment. Spermatophore quality was evaluated by spermatophore weight, sperm count, viability and proximate analysis of the treatment and shrimps. The content of three essential fatty acids, Arachidonic acid (AA), Eicosapentanoic acid (EPA) and Docosahexaenoic acid (DHA) from wild Penaeus monodon brood stock were evaluated in comparison with natural diet fed to P. monodon . Spermatophore of wild male brood stock contained higher levels of AA than those of artificial fed males. Polychaete has higher proportion of AA to EPA and DHA. At the end of the treatment the sperm viability and count, shrimp and spermatophore weight were significantly different among treatment and control (p<0.05). The present study concludes that the fresh squid diet is highly preferred over the diets influence on increasing the spermatophore quality, therefore use of fresh squid only is recommended for the maturation of male P. monodon brood stock. // //

Environmental characteristics of mangrove forest as a reference for development of mud Crab Scylla serrata cultivation: A case study in Mojo Village, Ulujami, Pemalang

Mud carb is one of the fisheries commodities that has a high economical value. Production of mud carb still depends on the wild stock for the seed, while the production from aquaculture sector has not been well established yet. Aquasilviculture is one of the options to develop aquaculture sector for this commodity in mangrove forest. This research aims to analyze and evaluate environment parameters that affected mud crab production in mangrove forest ecosystem at Mojo village, Ulujami, Pemalang. This research was conducted based on the survey method. The result from physical-chemistry analysis of the water in mud crab habitat showed that the most affecting factor in mud crab production was salinity. The production of mud crab tends to be high in salinity level between 21-25 g/L. From this result, site selection with stable water salinity should be considered for the development of mud crab aquasilviculture.

Phenotypic and community consequences of captive propagation in mosquitofish

Abstract Captive propagation can lead to phenotypic change in fish populations, but the broader community‐level consequences of captive phenotypes remain largely unknown. We investigate the degree to which captive propagation alters the phenotypes and ecological roles of fish stocked into wild communities. We focus on captive propagation of western mosquitofish (Gambusia affinis) for biocontrol, which represents one of the largest scale production efforts for any fish released into the wild. Captive propagation in mosquitofish consistently generated novel mixtures of morphological and behavioural traits that deviate from those of wild populations. A mesocosm experiment showed that mosquitofish from captive propagation facilities differ from wild fish in their effects on aquatic community structure by shifting their consumption to less‐mobile, benthic prey. Synthesis and applications. Captive‐propagated and translocated wild fish stocks not only differ in phenotype, but can have substantially different ecological effects on the communities into which they are introduced. Therefore, captive propagation programmes involving continual release should expand their concerns beyond altered phenotypes and fitness to include whether propagated fish actually provide the intended ecological roles and services associated with their wild counterparts. Infusions of wild alleles and captive environments that mimic wild conditions are recommended strategies to retain the desired ecological role of captive‐propagated fish.

Inbred zebrafish lines: A genetic repository for zebrafish researchers

Genetically uniform strains/inbred strains of animals are used in experiments that demand minimal genetic background variability and highly reproducible results. Modern genomic research is heavily dependent on inbred strains and they are widely used for identification of quantitative loci that affect evolutionarily and biomedically important traits, dissection of gene-gene and gene environmental interaction patterns, toxicity studies, immunology, reverse genetics, cancer research, etc. In mice, over 450 inbred strains have been described and in medaka over 13 inbred strains have been established. Owing to its numerous attributes zebrafish, Danio rerio, is one of the widely studied vertebrate model organisms, but comparable zebrafish inbred strains are not available to the scientific community. This is because of early onset of inbreeding depression causing high mortality of embryos and larvae and biased sex ratio that have been reported from earlier attempts to produce inbred lines. At CZeBraG-Centre for Zebrafish Breeding and Genetics Research facility of ICARCIFE, the inbred lines of zebrafish are being developed. The strategy followed is intense inbreeding coupled with strong positive selection for selected traits. The base population consisted of three wild stocks of zebrafish collected from rivers of North East India. Using nested mating design 84 families were produced in F1 generation and 46 inbred families were produced in F2 generation. Genetic parameters for growth traits like body weight and standard length were estimated. The overall heritability for body weight and standard length was estimated using animal model and found to be 0.43 ± 0.05 and 0.36 ± 0.04 respectively. Fecundity was also recorded but showed no significant variation among stocks. Inbreeding depression was studied by comparing the population means for body weight and standard length of F1 and F2 generation. The analysis suggested there was no inbreeding depression. Genetic monitoring of zebrafish is conducted using microsatellite markers. New PCR primers were designed for 20 selected microsatellite loci with high stringency. High Resolution Melting Curve analysis was used for genotyping individual zebrafish. In addition to developing inbred lines the centre is also maintaining the wild zebrafish stocks and has commenced supply of pedigreed zebrafish for researchers. In future zebrafish of known inbred levels (12.5 to 50% and above) can be supplied. Currently, the CZeBraG can house about 10000 adults, with separate facility for holding individual fish.

Study of Carbon Stock Potential and Carbon Absorption on Pamonean Land of Mentawai Community at Siberut Island

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New insights from nuclear and mitochondrial markers on the genetic diversity and structure of the Indian white shrimp Fenneropenaeus indicus among the marginal seas in the Indian Ocean

Genetic variation in wild stocks of a major commercial shrimp, Fenneropenaeus indicus, from the marginal seas in the Indian Ocean was analysed using polymorphic microsatellite loci and mitochondrial COI gene. The average observed heterozygosity (Ho = 0.44 ± 0.02) and the expected heterozygosity (He = 0.73 ± 0.01) were high across loci and populations indicating high microsatellite variation. Pairwise FST and Bayesian clustering indicated the occurrence of four genetically distinct stocks out of the eight sampled populations with implications for specific management approaches. Mantel test for isolation by distance proved that genetic differentiation is not related to geographic distance between populations. Mitochondrial COI sequence analysis showed concordant differentiation pattern as well indicated the relevance of COI in population genetics of shrimps. Pairwise ɸST and phylogenetic and Bayesian analyses revealed four distinct clades, as observed with nuclear markers. Divergence time analysis revealed the origin and initial divergence of F. indicus corresponds to late Miocene and divergence to phylogroups in the Pleistocene. BSP analysis presented a long stable population size with a slight decrease in the late Pleistocene and gradually expanded to the current status. The information here will be useful in commercial shrimp breeding and selection programmes and management of natural stocks of Indian white shrimp.

Governing the recreational dimension of global fisheries

Fisheries provide food. In industrialized nations, the overwhelming portion of seafood comes from a small number of commercial fishers and increasingly aquaculture (1). Fisheries also contribute to leisure and recreation. In developed nations, 1 in 10 people fishes for pleasure, amounting to at least 220 million recreational fishers worldwide (2, 3)—more than 5 times the number of commercial capture fishers (1). This means that the vast majority of people fishing today do so recreationally (Fig. 1). For too long, the considerable importance and impacts of recreational fisheries have been ignored. Image credit: Florian Mollers (photographer). And yet, for too long, the considerable importance and impacts of recreational fisheries have been ignored. Policymakers and managers need to acknowledge and address the recreational fisheries sector, rethink management objectives and schemes, involve recreational fishers in decision-making processes, incentivize sustainable angler behavior, and improve data collection and monitoring. Recreational fisheries deserve to be considered on equal footing with commercial fisheries, particularly in mixed coastal fisheries. Although commercial capture fisheries globally harvest about 8 times the fish biomass caught by recreational fisheries (4), in many localities recreational landings now rival or even exceed the biomass removals by commercial fisheries. In inland waters in the temperate zone, recreational anglers are now the predominant users of wild fish stocks (5), and recreational fishers have become prevalent in many coastal and marine fisheries (6, 7). Globally, recreational fishers catch about 47 billion individual fish per year, of which more than half are released alive (4), either because of harvest regulations or in response to personal ethics (8). Despite high release rates, fishing for food is a strong motive and justification for recreational fisheries (9). Beyond nutritional benefits, recreational fisheries provide a range of psychological, social, educational, and economic benefits to fishers and society that are … [↵][1]2To whom correspondence should be addressed. Email: arlinghaus{at}igb-berlin.de. [1]: #xref-corresp-1-1