Browsing by Subject "fish"

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  • Vilizzi, Lorenzo; Copp, Gordon H.; Adamovich, Boris; Almeida, David; Chan, Joleen; Davison, Phil I.; Dembski, Samuel; Ekmekçi, F. Güler; Ferincz, Árpád; Forneck, Sandra C.; Hill, Jeffrey E.; Kim, Jeong-Eun; Koutsikos, Nicholas; Leuven, Rob S. E. W.; Luna, Sergio A.; Magalhães, Filomena; Marr, Sean M.; Mendoza, Roberto; Mourão, Carlos F.; Neal, J. Wesley; Onikura, Norio; Perdikaris, Costas; Piria, Marina; Poulet, Nicolas; Puntila, Riikka; Range, Inês L.; Simonović, Predrag; Ribeiro, Filipe; Tarkan, Ali Serhan; Troca, Débora F. A.; Vardakas, Leonidas; Verreycken, Hugo; Vintsek, Lizaveta; Weyl, Olaf L. F.; Yeo, Darren C. J.; Zeng, Yiwen (Springer, 2019)
    Reviews in Fish Biology & Fisheries 29(3), 529-568
    The freshwater Fish Invasiveness Screening Kit (FISK) has been applied in 35 risk assessment areas in 45 countries across the six inhabited continents (11 applications using FISK v1; 25 using FISK v2). The present study aimed: to assess the breadth of FISK applications and the confidence (certainty) levels associated with the decision-support tool’s 49 questions and its ability to distinguish between taxa of low-to-medium and high risk of becoming invasive, and thus provide climate-specific, generalised, calibrated thresholds for risk level categorisation; and to identify the most potentially invasive freshwater fish species on a global level. The 1973 risk assessments were carried out by 70 + experts on 372 taxa (47 of the 51 species listed as invasive in the Global Invasive Species Database www.iucngisd.org/gisd/), which in decreasing order of importance belonged to the taxonomic Orders Cypriniformes, Perciformes, Siluriformes, Characiformes, Salmoniformes, Cyprinodontiformes, with the remaining ≈ 8% of taxa distributed across an additional 13 orders. The most widely-screened species (in decreasing importance) were: grass carp Ctenopharyngodon idella, common carp Cyprinus carpio, rainbow trout Oncorhynchus mykiss, silver carp Hypophthalmichthys molitrix and topmouth gudgeon Pseudorasbora parva. Nine ‘globally’ high risk species were identified: common carp, black bullhead Ameiurus melas, round goby Neogobius melanostomus, Chinese (Amur) sleeper Perccottus glenii, brown bullhead Ameiurus nebulosus, eastern mosquitofish Gambusia holbrooki, largemouth (black) bass Micropterus salmoides, pumpkinseed Lepomis gibbosus and pikeperch Sander lucioperca. The relevance of this global review to policy, legislation, and risk assessment and management procedures is discussed.
  • Lyhs, Ulrike; Björkroth, Johanna; Korkeala, Hannu (Elsevier, 1999)
    A total of 405 lactic acid bacteria (LAB) isolated from spoiled, vacuum-packaged, salted, sodium nitrite- or potassium nitrate-treated, cold-smoked rainbow trout stored at 48C or 88C were characterised and identified using a molecular method. The isolates were initially classified according to their restriction endonuclease profiles using HindIII and EcoRI restriction endonucleases and further characterised by rRNA gene restriction patterns (ribotypes). Numerical analysis of these ribopatterns was performed together with 19 reference LAB strain patterns in order to identify the isolates to species level. The strains were divided with HindIII and EcoRI ribopatterns into ten and nine clusters at the similarity level of 65% and 50%, respectively. The Leuconostoc-clusters and the Lb. sakei /Lb. curvatus-clusters formed the two main groups. Only one isolate was identified as Lactobacillus plantarum and no Carnobacterium strains were discovered. For both enzymes, the 35 isolates possessing six individual ribotypes and forming five clusters could not be identified further with the reference strains used. The relative proportion of Leuconostoc mesenteroides subsp. mesenteroides was higher in all samples stored at 48C. Most of the Leuconostoc citreum were found in the samples stored at 88C, and particularly in the nitrite-treated samples.
  • Ehrnsten, Eva; Bauer, Barbara; Gustafsson, Bo G. (2019)
    The responses of food webs to simultaneous changes in several environmental drivers are still poorly understood. As a contribution to filling this knowledge gap, we investigated the major pathways through which two interlinked environmental drivers, eutrophication and climate, affect the biomass and community composition of fish and benthic macrofauna. For this aim, we conducted a systematic sensitivity analysis using two models simulating the dynamics of benthic and pelagic food webs in the Baltic Sea. We varied environmental forcing representing primary productivity, oxygen conditions and water temperature in all possible combinations, over a range representative of expected changes during the 21st century. Both models indicated that increased primary productivity leads to biomass increase in all parts of the system, however, counteracted by expanding hypoxia. Effects of temperature were complex, but generally small compared to the other drivers. Similarities across models give confidence in the main results, but we also found differences due to different representations of the food web in the two models. While both models predicted a shift in benthic community composition toward an increased abundance of Limecola (Macoma) balthica with increasing productivity, the effects on deposit-feeding and predatory benthic groups depended on the presence of fish predators in the model. The model results indicate that nutrient loads are a stronger driver of change for ecosystem functions in the Baltic Sea than climate change, but it is important to consider the combined effects of these drivers for proper management of the marine environment.
  • Key, Timothy J.; Appleby, Paul N.; Bradbury, Kathryn E.; Sweeting, Michael; Wood, Angela; Johansson, Ingegerd; Kuehn, Tilman; Steur, Marinka; Weiderpass, Elisabete; Wennberg, Maria; Wuertz, Anne Mette Lund; Agudo, Antonio; Andersson, Jonas; Arriola, Larraitz; Boeing, Heiner; Boer, Jolanda M. A.; Bonnet, Fabrice; Boutron-Ruault, Marie-Christine; Cross, Amanda J.; Ericson, Ulrika; Fagherazzi, Guy; Ferrari, Pietro; Gunter, Marc; Huerta, Jose Maria; Katzke, Verena; Khaw, Kay-Tee; Krogh, Vittorio; La Vecchia, Carlo; Matullo, Giuseppe; Moreno-Iribas, Conchi; Naska, Androniki; Nilsson, Lena Maria; Olsen, Anja; Overvad, Kim; Palli, Domenico; Panico, Salvatore; Molina-Portillo, Elena; Quiros, J. Ramon; Skeie, Guri; Sluijs, Ivonne; Sonestedt, Emily; Stepien, Magdalena; Tjonneland, Anne; Trichopoulou, Antonia; Tumino, Rosario; Tzoulaki, Ioanna; van der Schouw, Yvonne T.; Verschuren, W. M. Monique; di Angelantonio, Emanuele; Langenberg, Claudia; Forouhi, Nita; Wareham, Nick; Butterworth, Adam; Riboli, Elio; Danesh, John (2019)
    Background: There is uncertainty about the relevance of animal foods to the pathogenesis of ischemic heart disease (IHD). We examined meat, fish, dairy products, and eggs and risk for IHD in the pan-European EPIC cohort (European Prospective Investigation Into Cancer and Nutrition). Methods: In this prospective study of 409 885 men and women in 9 European countries, diet was assessed with validated questionnaires and calibrated with 24-hour recalls. Lipids and blood pressure were measured in a subsample. During a mean of 12.6 years of follow-up, 7198 participants had a myocardial infarction or died of IHD. The relationships of animal foods with risk were examined with Cox regression with adjustment for other animal foods and relevant covariates. Results: The hazard ratio (HR) for IHD was 1.19 (95% CI, 1.06-1.33) for a 100-g/d increment in intake of red and processed meat, and this remained significant after exclusion of the first 4 years of follow-up (HR, 1.25 [95% CI, 1.09-1.42]). Risk was inversely associated with intakes of yogurt (HR, 0.93 [95% CI, 0.89-0.98] per 100-g/d increment), cheese (HR, 0.92 [95% CI, 0.86-0.98] per 30-g/d increment), and eggs (HR, 0.93 [95% CI, 0.88-0.99] per 20-g/d increment); the associations with yogurt and eggs were attenuated and nonsignificant after exclusion of the first 4 years of follow-up. Risk was not significantly associated with intakes of poultry, fish, or milk. In analyses modeling dietary substitutions, replacement of 100 kcal/d from red and processed meat with 100 kcal/d from fatty fish, yogurt, cheese, or eggs was associated with approximate to 20% lower risk of IHD. Consumption of red and processed meat was positively associated with serum non-high-density lipoprotein cholesterol concentration and systolic blood pressure, and consumption of cheese was inversely associated with serum non-high-density lipoprotein cholesterol. Conclusions: Risk for IHD was positively associated with consumption of red and processed meat and inversely associated with consumption of yogurt, cheese, and eggs, although the associations with yogurt and eggs may be influenced by reverse causation bias. It is not clear whether the associations with red and processed meat and cheese reflect causality, but they were consistent with the associations of these foods with plasma non-high-density lipoprotein cholesterol and for red and processed meat with systolic blood pressure, which could mediate such effects.
  • Cotter, S. C.; Pincheira-Donoso, D.; Thorogood, R. (2019)
    Parasitic interactions are so ubiquitous that all multicellular organisms have evolved a system of defences to reduce their costs, whether the parasites they encounter are the “classic parasites” that feed on the individual, or “brood parasites” that usurp parental care. Many parallels have been drawn between defences deployed against both types of parasite, but typically, whilst defences against classic parasites have been selected to protect survival, those against brood parasites have been selected to protect the parent’s inclusive fitness, suggesting that the selection pressures they impose are fundamentally different. However, there is another class of defences against classic parasites that have specifically been selected to protect an individual’s inclusive fitness, known as “social immunity”. Social immune responses include the anti-parasite defences typically provided for others in kin-structured groups, such as the antifungal secretions produced by termite workers to protect the brood. Defences against brood parasites, therefore, are more closely aligned with social immune responses. Much like social immunity, host defences against brood parasitism are employed by a donor (a parent) for the benefit of one or more recipients (typically kin), and as with social defences against classic parasites, defences have therefore evolved to protect the donor’s inclusive fitness, not the survival or ultimately the fitness of individual recipients This can lead to severe conflicts between the different parties, whose interests are not always aligned. Here we consider defences against brood parasitism in the light of social immunity, at different stages of parasite encounter, addressing where conflicts occur and how they might be resolved. We finish with considering how this approach could help us to address longstanding questions in our understanding of brood parasitism.
  • Kumar, Eva; Koponen, Jani; Rantakokko, Panu; Airaksinen, Riikka; Ruokojärvi, Päivi; Kiviranta, Hannu; Vuorinen, Pekka J.; Myllylä, Timo; Keinänen, Marja; Raitaniemi, Jari; Mannio, Jaakko; Junttila, Ville; Nieminen, Janne; Venäläinen, Eija-Riitta; Jestoi, Marika (Elsevier BV, 2022)
    Chemosphere
    Occurrence and distribution of perfluoroalkyl acids (PFAAs), a sub-category of per- and polyfluoroalkyl substances (PFASs), is widespread in the environment. Food, especially fish meat, is a major pathway via which humans are exposed to PFAAs. As fish is an integral part of Nordic diet, therefore, in this study, several fish species, caught in selected Baltic Sea basins and freshwater bodies of Finland, were analysed for PFAAs. Perfluorooctane sulfonate (PFOS) was detected in all Baltic Sea fish samples and in >80% fish samples from freshwaters. PFOS contributed between 46 and 100% to the total PFAA concentration in Baltic Sea fish samples and between 19 and 28% in fish samples from freshwaters. Geographically, concentration ratios of PFOS to other PFAAs differed between fish from the Baltic Sea and Finnish lakes suggesting that distribution of PFAAs differ in these environments. Results were compared with current safety thresholds – environmental quality standard for biota (EQSbiota) set by the European Commission and a group tolerable weekly intake (TWI) for the sum of four PFASs (∑PFAS-4) i.e. perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonate (PFHxS) and PFOS, recommended by the European Food Authority (EFSA). EQSbiota compliance was observed for PFOS in all species except smelt caught in the Baltic Sea and also in the River Aurajoki, where smelt had migrated from the Baltic Sea for spawning. Moderate consumption of most Baltic fishes (200 g week−1) results in an exceedance of the new TWI (4.4 ng kg−1 body weight week−1) for ∑PFAS-4.
  • Toli, Elisavet A.; Noreikiene, Kristina; De Faveri, Jacquelin; Merila, Juha (2017)
    Evidence for phenotypic plasticity in brain size and the size of different brain parts is widespread, but experimental investigations into this effect remain scarce and are usually conducted using individuals from a single population. As the costs and benefits of plasticity may differ among populations, the extent of brain plasticity may also differ from one population to another. In a common garden experiment conducted with three-spined sticklebacks (Gasterosteus aculeatus) originating from four different populations, we investigated whether environmental enrichment (aquaria provided with structural complexity) caused an increase in the brain size or size of different brain parts compared to controls (bare aquaria). We found no evidence for a positive effect of environmental enrichment on brain size or size of different brain parts in either of the sexes in any of the populations. However, in all populations, males had larger brains than females, and the degree of sexual size dimorphism (SSD) in relative brain size ranged from 5.1 to 11.6% across the populations. Evidence was also found for genetically based differences in relative brain size among populations, as well as for plasticity in the size of different brain parts, as evidenced by consistent size differences among replicate blocks that differed in their temperature.
  • Lyhs, Ulrike; Korkeala, Hannu; Björkroth, Johanna (Elsevier, 2002)
    A total of 296 lactic acid bacteria (LAB) isolated from spoiled, vacuum-packaged ‘gravad’ rainbow trout stored at 3ºC and 8ºC were characterised and identified using a molecular approach. The isolates were initially grouped according to their HindIII restriction endonuclease profiles and further identified to species level using a rRNA gene restriction pattern (ribotype) identification database. Lactobacillus sakei, Lactobacillus curvatus and Carnobacterium piscicola were the three main species detected. Only one isolate was identified as Carnobacterium divergens. Most of the carnobacteria were found in the samples stored at 3ºC. The relative proportion of L. sakei was higher in the samples stored at 8ºC.
  • Braaten, Hans Fredrik Veiteberg; Akerblom, Staffan; Kahilainen, Kimmo K.; Rask, Martti; Vuorenmaa, Jussi; Mannio, Jaakko; Malinen, Tommi; Lydersen, Espen; Poste, Amanda E.; Amundsen, Per-Arne; Kashulin, Nicholas; Kashulina, Tatiana; Terentyev, Petr; Christensen, Guttorm; de Wit, Heleen A. (American Chemical Society, 2019)
    Environmental Science & Technology 2019 53 (4), 1834-1843
    Temporally (1965–2015) and spatially (55°–70°N) extensive records of total mercury (Hg) in freshwater fish showed consistent declines in boreal and subarctic Fennoscandia. The database contains 54 560 fish entries (n: pike > perch ≫ brown trout > roach ≈ Arctic charr) from 3132 lakes across Sweden, Finland, Norway, and Russian Murmansk area. 74% of the lakes did not meet the 0.5 ppm limit to protect human health. However, after 2000 only 25% of the lakes exceeded this level, indicating improved environmental status. In lakes where local pollution sources were identified, pike and perch Hg concentrations were significantly higher between 1965 and 1990 compared to values after 1995, likely an effect of implemented reduction measures. In lakes where Hg originated from long-range transboundary air pollution (LRTAP), consistent Hg declines (3–7‰ per year) were found for perch and pike in both boreal and subarctic Fennoscandia, suggesting common environmental controls. Hg in perch and pike in LRTAP lakes showed minimal declines with latitude, suggesting that drivers affected by temperature, such as growth dilution, counteracted Hg loading and food web exposure. We recommend that future fish Hg monitoring sampling design should include repeated sampling and collection of pollution history, water chemistry, fish age, and stable isotopes to enable evaluation of emission reduction policies.
  • Zidbeck, Erika (Helsingin yliopisto, 2018)
    In this Master’s thesis, microplastic (<5 mm) ingestion by coastal fish in Finland was investigated. Fish were caught at nine locations on the coast of Finland. Water samples were taken at seven locations. The research questions were: How much microplastics are there in coastal fish in Finland? Are there differences in the frequency of microplastic ingestion by fish between different locations or species? Is there a relationship between the size of the fish and the presence of ingested plastic particles? Is there a relationship between the stomach fullness and the presence of ingested plastic particles? Does the frequency of microplastic ingestion by fish correlate with the amount of microplastics in seawater in the same locations? The gastrointestinal tracts of 503 fish were analysed. Microplastics were found in 40 fish (8 %). The frequency of fish with plastic was significantly higher in Kivinokka, Helsinki than in other locations studied. No relationship was found between the size or the species of the fish and the presence of ingested plastic particles. Also, no relationship was found between the stomach fullness and plastic ingested. There was no correlation between the frequency of microplastic ingestion by fish and the amount of microplastics in seawater. The results of the thesis were compared to previous research results from the open sea areas of the northern Baltic Sea. The comparison suggests that the ingestion of microplastics is more common in coastal fish in Finland than in the open water fish in the northern Baltic Sea. This thesis provides the first published record of plastic particles in the gastrointestinal tracts of coastal fish in Finland. Long-term studies are recommended in order to confirm the results.
  • Junttila, Ville; Vähä, Emmi; Perkola, Noora; Räike, Antti; Siimes, Katri; Mehtonen, Jukka; Kankaanpää, Harri; Mannio, Jaakko (MDPI, 2019)
    Water
    The concentrations of per- and polyfluoroalkyl substances (PFASs) in the Finnish aquatic environment were measured in riverine waters and in inland, coastal and open sea fish. In addition, the PFAS load to the Baltic Sea from 11 rivers was calculated. Measurements show that PFASs, including restricted perfluorooctane sulfonic acid (PFOS), are widely present in the Finnish aquatic environment. At three out of 45 sampling sites, the concentration of PFOS in fish exceeded the environmental quality standard (EQS) of the Water Framework Directive (WFD). The annual average (AA) ∑23PFAS concentration in surface waters ranged from 1.8 to 42 ng L−1 and the concentration of PFOS exceeded the AA-EQS in three out of 13 water bodies. In European perch (Perca fluviatilis) and Baltic herring (Clupea harengus membras), the ∑PFAS concentration ranged from 0.98 to 1 µg kg−1 f.w. (fresh weight) and from 0.2 to 2.4 µg kg−1 f.w., respectively. The highest concentrations in both surface water and fish were found in waters of southern Finland. The riverine export of ∑10PFAS to the Baltic Sea from individual rivers ranged from 0.4 kg yr−1 to 18 kg yr−1. PFAS concentrations in fish of point-source-polluted sites and coastal sites were higher compared to fish of open sea or diffusely polluted sites. The PFAS profiles in surface waters of background sites were different from other sites. This study shows that PFASs are widely found in the Finnish aquatic environment. Different PFAS profiles in samples from background areas and densely populated areas indicate diverse sources of PFASs. Although atmospheric deposition has a substantial influence on PFAS occurrence in remote areas, it is not the dominant source of all PFASs to the aquatic environment of Finland. Rather, wastewaters and presumably contaminated land areas are major sources of PFASs to this aquatic environment.
  • Tokodi, Nada; Backovic, Damjana Drobac; Luji, Jelena; Šcekic, Ilija; Simic, Snežana; Đorđevic, Nevena; Dulic, Tamara; Miljanovic, Branko; Kitanovic, Nevena; Marinovic, Zoran; Savela, Henna; Meriluoto, Jussi; Svircev, Zorica (MDPI, 2020)
    Water 12 1 (2020)
    For 50 years persistent cyanobacterial blooms have been observed in Lake Ludoš (Serbia), a wetland area of international significance listed as a Ramsar site. Cyanobacteria and cyanotoxins can affect many organisms, including valuable flora and fauna, such as rare and endangered bird species living or visiting the lake. The aim was to carry out monitoring, estimate the current status of the lake, and discuss potential resolutions. Results obtained showed: (a) the poor chemical state of the lake; (b) the presence of potentially toxic (genera Dolichospermum, Microcystis, Planktothrix, Chroococcus, Oscillatoria, Woronichinia and dominant species Limnothrix redekei and Pseudanabaena limnetica) and invasive cyanobacterial species Raphidiopsis raciborskii; (c) the detection of microcystin (MC) and saxitoxin (STX) coding genes in biomass samples; (d) the detection of several microcystin variants (MC-LR, MC-dmLR, MC-RR, MC-dmRR, MC-LF) in water samples; (e) histopathological alterations in fish liver, kidney and gills. The potential health risk to all organisms in the ecosystem and the ecosystem itself is thus still real and present. Although there is still no resolution in sight, urgent remediation measures are needed to alleviate the incessant cyanobacterial problem in Lake Ludoš to break this ecosystem out of the perpetual state of limbo in which it has been trapped for quite some time.
  • Hemida, Manal B. M.; Salin, Siru; Vuori, Kristiina A.; Moore, Robin; Anturaniemi, Johanna; Rosendahl, Sarah; Barrouin-Melo, Stella Maria; Hielm-Bjorkman, Anna (2021)
    Background The increased prevalence of atopic dermatitis (AD) in dogs necessitates research in its disease etiology. Objectives To explore the association between puppyhood dietary exposures and prevalence of owner-reported allergy/atopy skin signs (AASS) after the age of 1 year. Animals Four thousand and twenty-two dogs were eligible, 1158 cases, and 2864 controls. Methods This cross-sectional hypothesis-driven observational study was extracted from the DogRisk food frequency questionnaire. Forty-six food items and the ratio of 4 major diet types were tested for their association with AASS incidence later in life. Potential puppyhood dietary risk factors for AASS incidence were specified using binary multivariable logistic regression. The model was adjusted for age and sex. Results Eating raw tripe (odds ratio, 95% confidence intervals OR, 95% CI = 0.36, 0.16-0.79; P = .01), raw organ meats (OR, 95% CI = 0.23, 0.08-0.67; P = .007), human meal leftovers, and fish oil supplements as well as eating more that 20% of the diet as raw and/or
  • McLeod, Anne; Leroux, Shawn J.; Gravel, Dominique; Chu, Cindy; Cirtwill, Alyssa R.; Fortin, Marie-Josee; Galiana, Nuria; Poisot, Timothee; Wood, Spencer A. (2021)
    Collecting well-resolved empirical trophic networks requires significant time, money and expertise, yet we are still lacking knowledge on how sampling effort and bias impact the estimation of network structure. Filling this gap is a critical first step towards creating accurate representations of ecological networks and for teasing apart the impact of sampling compared to ecological and evolutionary processes that are known to create spatio-temporal variation in network structure. We use a well-sampled spatial dataset of lake food webs to examine how sample effort influences network structure. Specifically, we predict asymptotic network properties (ANPs) for our dataset by comparing lake-specific network metrics with increasing sampling effort. We then contrast three sampling strategies - random, smallest lake to largest lake or largest lake to smallest lake - to assess which strategy best captures the regional metaweb (i.e. network of all potential interactions) network properties. We demonstrate metric-specific relationships between sample effort and network metrics, often diverging from the ANPs. For example, low sample effort can contribute to much lower and poorer estimates of closeness centralization, as compared to approximations of modularity with similar sample efforts. In fact, many network metrics (e.g. connectance) have a quadratic relationship with sample effort indicating a sampling 'sweet spot', which represents optimal sample effort for a close approximation of the ANP. Further, we find that sampling larger lakes followed by smaller lakes is a more optimal sampling strategy for capturing metaweb properties in this lentic ecosystem. Overall, we provide clear ways to better understand the impacts of sampling bias in food-web studies which may be particularly critical given the rapid increase in studies comparing food webs across space and time.
  • Konijnendijk, Nellie; Shikano, Takahito; Daneels, Dorien; Volckaert, Filip A. M.; Raeymaekers, Joost A. M. (2015)
    Local adaptation is often obvious when gene flow is impeded, such as observed at large spatial scales and across strong ecological contrasts. However, it becomes less certain at small scales such as between adjacent populations or across weak ecological contrasts, when gene flow is strong. While studies on genomic adaptation tend to focus on the former, less is known about the genomic targets of natural selection in the latter situation. In this study, we investigate genomic adaptation in populations of the three-spined stickleback Gasterosteus aculeatus L. across a small-scale ecological transition with salinities ranging from brackish to fresh. Adaptation to salinity has been repeatedly demonstrated in this species. A genome scan based on 87 microsatellite markers revealed only few signatures of selection, likely owing to the constraints that homogenizing gene flow puts on adaptive divergence. However, the detected loci appear repeatedly as targets of selection in similar studies of genomic adaptation in the three-spined stickleback. We conclude that the signature of genomic selection in the face of strong gene flow is weak, yet detectable. We argue that the range of studies of genomic divergence should be extended to include more systems characterized by limited geographical and ecological isolation, which is often a realistic setting in nature.
  • Sutela, Tapio; Vehanen, Teppo; Jounela, Pekka; Aroviita, Jukka (John Wiley & Sons, 2021)
    Ecology and Evolution 11 (15), 10457-10467
    Species–environment relationships were studied between the occurrence of 13 fish and lamprey species and 9 mainly map-based environmental variables of Finnish boreal small streams. A self-organizing map (SOM) analysis showed strong relationships between the fish species and environmental variables in a single model (explained variance 55.9%). Besides basic environmental variables such as altitude, catchment size, and mean temperature, land cover variables were also explored. A logistic regression analysis indicated that the occurrence probability of brown trout, Salmo trutta L., decreased with an increasing percentage of peatland ditch drainage in the upper catchment. Ninespine stickleback, Pungitius pungitius (L.), and three-spined stickleback, Gasterosteus aculeatus L., seemed to benefit from urban areas in the upper catchment. Discovered relationships between fish species occurrence and land-use attributes are encouraging for the development of fish-based bioassessment for small streams. The presented ordination of the fish species in the mean temperature gradient will help in predicting fish community responses to climate change.
  • Emameh, Reza Zolfaghari; Purmonen, Sami; Sukura, Antti; Parkkila, Seppo (2018)
    Foodborne parasites are a source of human parasitic infection. Zoonotic infections of humans arise from a variety of domestic and wild animals, including sheep, goats, cattle, camels, horses, pigs, boars, bears, felines, canids, amphibians, reptiles, poultry, and aquatic animals such as fishes and shrimp. Therefore, the implementation of efficient, accessible, and controllable inspection policies for livestock, fisheries, slaughterhouses, and meat processing and packaging companies is highly recommended. In addition, more attention should be paid to the education of auditors from the quality control (QC) and assurance sectors, livestock breeders, the fishery sector, and meat inspection veterinarians in developing countries with high incidence of zoonotic parasitic infections. Furthermore, both the diagnosis of zoonotic parasitic infections by inexpensive, accessible, and reliable identification methods and the organization of effective control systems with sufficient supervision of product quality are other areas to which more attention should be paid. In this review, we present some examples of successful inspection policies and recent updates on present conventional, serologic, and molecular diagnostic methods for zoonotic foodborne parasites from both human infection and animal-derived foods.
  • Lyhs, Ulrike; Björkroth, Johanna; Hyytiä, Eija; Korkeala, Hannu (Elsevier, 1998)
    The spoilage flora of vacuum-packaged, salted, cold-smoked rainbow trout fillets, with or without the addition of nitrate or nitrite, stored at 4°C and 8°C, was studied. Of 620 isolates, lactic acid bacteria were the major fraction (76%), predominating in all samples of spoiled product. However, the phenotypical tests used were insufficient to identify the lactic acid bacteria to the species level. Gram-positive, catalase-positive cocci, Gram-negative, oxidase-negative rods and Gram-negative, oxidase-positive rods were found in 6%, 16% and 2% of the samples, respectively. Of 39 Gram-positive, catalase-positive cocci, 29 were identified as staphylococci and 10 as micrococci. Eighty-five isolates were found to belong to the family Enterobacteriaceae, with 45 of those being Serratia plymuthica. Eleven isolates from the nitrate treated samples stored at 8°C were identified as Pseudomonas aeruginosa. The occurrence of P. aeruginosa and staphylococci in the nitrate-containing samples, stored at 8°C, may cause problems with respect to the safety of the product. The types of lactic acid and other bacteria in the spoilage flora were generally reduced by the addition of nitrate or nitrite to fillets.
  • Van Steenberge, Maarten W.; Vanhove, Maarten P. M.; Manda, Auguste Chocha; Larmuseau, Maarten H. D.; Swart, Belinda L.; Khang'Mate, Faustin; Arndt, Allan; Hellemans, Bart; Van Houdt, Jeroen; Micha, Jean-Claude; Koblmueller, Stephan; Roodt-Wilding, Rouvay; Volckaert, Filip A. M. (2020)
    Aim The formation history of Africa's current river basins remains largely unknown. In order to date changes in landscape and climate, we studied the biogeography of the African freshwater fish with the largest natural distribution. We also validated biogeographical units. Location Continental Africa. Taxon Clarias gariepinus sl. Methods We investigated mitochondrial cytb sequences of 443 individuals from 97 localities, using a haplotype network and a genetic landscape analysis. We inferred a dated phylogeny using maximum likelihood and Bayesian inference approaches and reconstructed ancestral areas with S-DEC and S-DIVA models. Microsatellite genotyping complemented the mitochondrial approach in the Congo basin, where the latter revealed complex patterns. Results Limited differentiation is found in northern and south-western Africa, and sharp genetic differentiation in the continent's east and centre. Populations with affinities to neighbouring basins occur at the edges of the Congo province. High diversity exists in the south of the Congo basin. The Zambezi province is partitioned into eastern, central and western sectors. In the east, specimens were related to those from the Congo. In the west, they were similar to Southern representatives. Phylogenetic inference placed the origin of C. gariepinus in the East Coast, with intraspecific diversification starting around the Great Lakes. These events occurred ca. 4.8-1.65 and 2.3-0.8 MYA respectively. Main conclusions Clades of C. gariepinus sl. show a clear geographical signature. The origin of C. gariepinus in the East Coast and diversification around the Great Lakes coincided with the periods of increased aridity. Low genetic differentiation in northern and southern Africa may result from connectivity during recent periods of higher rainfall. In contrast to other widespread African freshwater fish, colonization rather than extinction seemed to mediate distribution patterns. This can be explained by a high ecological tolerance. We highlight the species' suitability to study landscape and climate evolution at various scales.
  • Voigt, H.-R. (Karolinum-Nakladatelstvi Univerzity Karlovy, 2000)