| 1. |
- Asnicar, Davide, et al.
(författare)
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Sand Goby : An Ecologically Relevant Species for Behavioural Ecotoxicology
- 2018
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Ingår i: Fishes. - : MDPI. - 2410-3888. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Locomotion-based behavioural endpoints have been suggested as suitable sublethal endpoints for human and environmental hazard assessment, as well as for biomonitoring applications. Larval stages of the sand goby (Pomatoschistus minutus) possess a number of attractive qualities for experimental testing that make it a promising species in behavioural ecotoxicology. Here, we present a study aimed at developing a toolkit for using the sand goby as novel species for ecotoxicological studies and using locomotion as an alternative endpoint in toxicity testing. Exposure to three contaminants (copper (Cu), di-butyl phthalate (DBP) and perfluorooctanoic acid (PFOA) was tested in the early life stages of the sand goby and the locomotion patterns of the larvae were quantified using an automatic tracking system. In a photo-motor test, sand goby larvae displayed substantially higher activity in light than in dark cycles. Furthermore, all tested compounds exerted behavioural alterations, such as hypo- and hyperactivity. Our experimental results show that sand goby larvae produce robust and quantifiable locomotive responses, which could be used within an ecotoxicological context for assessing the behavioural toxicity of environmental pollutants, with particular relevance in the Nordic region. This study thus suggests that sand goby larvae have potential as an environmentally relevant species for behavioural ecotoxicology, and as such offer an alternative to standard model species.
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| 2. |
- Mulokozi, Deogratias Pius, et al.
(författare)
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An ecological and economical assessment of integrated amaranth (Amaranthus hybridus) and Nile tilapia (Oreochromis niloticus) farming in Dar es Salaam, Tanzania
- 2020
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Ingår i: Fishes. - : MDPI AG. - 2410-3888. ; 5:3
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Tidskriftsartikel (refereegranskat)abstract
- Organic wastes can be recycled in an ecologically sound way in fishponds by applying integrated agriculture and aquaculture systems (IAA). This kind of waste recycling can help to protect the environment from pollution and improve fishpond yields. Additionally, IAA provides an opportunity for diversification of the output from two or more existing subsystems leading to higher overall farm economic returns. This study explored the potential application of amaranth wastes (AW) as a dietary ingredient for tilapia in a tilapia-amaranths integrated system (ITA). An experimental diet (AD) contained 10% (based on the control diet, CD) inclusion of AW collected from a nearby vegetable market. The experiments included triplicate treatments with; (i) fish fed on AD, where the pond water was used for irrigating the amaranth plants (IAA-fish), and (ii) fish fed on CD, where no pond water was used for irrigating the amaranth plants (non-IAA fish). 90 days after fish stocking, eighteen 4 m2 amaranth plots were prepared and treated with (i) tap water without fertilization (control amaranths), (ii) water from IAA-fish pond and organically fertilized (IAA amaranths), and (iii) tap water and inorganically fertilized (non-IAA amaranths). The use of AW improved the fish feed conversion ratio. The overall net income from ITA was 3.2, 2.3, 2.6, and 1.8 higher than from non-IAA amaranths, IAA-amaranths, non-IAA fish, and IAA fish sub-systems respectively.
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| 3. |
- Olsson, Jens
(författare)
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Past and Current Trends of Coastal Predatory Fish in the Baltic Sea with a Focus on Perch, Pike, and Pikeperch
- 2019
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Ingår i: Fishes. - : MDPI AG. - 2410-3888. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Coastal predatory fish are of key importance for the provisioning of ecosystem services in the Baltic Sea. Worldwide, however, there has been a general and sharp decline in predatory fish populations, in turn threatening the viability and function of marine ecosystems. On the basis of the literature, the past (data until the 2000s) and current (data until early and mid 2010s) trends in abundance of coastal predatory fish in the Baltic Sea are reviewed in this paper. Potentially important impacting factors behind the temporal development of the populations and measures to strengthen and restore them are also discussed. Available data from coastal fish monitoring programs suggest a stable or increasing abundance of coastal predatory fish as a functional group and for the species perch in the majority of areas assessed in the Baltic Sea. For pike and pikeperch, data to support assessments is scarce, but suggest substantial declines in the abundance of both species in most assessed areas. The impacting factors behind these patterns vary between species and areas, but include climate, habitat exploitation, fishing, and species-interactions in the coastal food web. Measures to restore and support coastal predatory fish communities should follow an ecosystem-based approach to management and include efforts to regulate fisheries sectors in combination with habitat protection and restoration.
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| 4. |
- Pius Mmanda, Francis, et al.
(författare)
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Digestibility of local feed ingredients in tilapia Oreochromis niloticus Juveniles, determined on faeces collected by siphoning or stripping
- 2020
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Ingår i: Fishes. - : MDPI AG. - 2410-3888. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Eight locally available protein source ingredients in Tanzania were selected for assessment of apparent digestibility (AD) in tilapia Oreochromis niloticus, using faeces samples collected by siphoning or stripping. The selected protein source ingredients were Lake Victoria sardines (FM), brewers spent yeast (BSY), moringa leaves (ML), freshwater shrimp (FSH), marine shrimp (MSH), cattle blood (CB), duckweed (DW) and fish frames (FF). The AD (%) of dry matter (DM), organic matter (OM) and crude protein (CP) was unaffected (p > 0.782–0.901) by the faeces collection method (i.e., siphoning or stripping), with correlation coefficient (r) of 0.98, 0.99 and 0.93 between AD values for DM, OM and CP, respectively, following siphoning and stripping. The AD (%) of DM, OM, CP and gross energy (GE) in the test ingredients differed (p < 0.0001). The AD (%) of DM and OM was lowest in BSY and DW, followed in increasing order by ML, MSH, FF, FSH and CB. In general, the AD (%) of CP was high (>76%), but with a low value (46%) for DW. The AD (%) of GE was closely correlated (r = 0.96) with the AD of OM. In conclusion, FSH, MSH, CB, FF, BSY and ML have acceptable protein digestibility to be used in tilapia diet formulation.
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| 5. |
- Wagner, Liane, et al.
(författare)
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1H NMR-Based Metabolomics and Lipid Analyses Revealed the Effect of Dietary Replacement of Microbial Extracts or Mussel Meal with Fish Meal to Arctic Charr (Salvelinus alpinus)
- 2019
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Ingår i: Fishes. - : MDPI AG. - 2410-3888. ; 4
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Tidskriftsartikel (refereegranskat)abstract
- The effects of replacing 40% of dietary fish meal (FM) in a reference diet (REF) with either mussel meal (MM), zygomycete fungi (ZYG), extracted baker's yeast (EY), or non-extracted baker's yeast (NY) on the lipid and metabolic profile of Arctic charr (Salvelinus alpinus) were investigated. After a 14-week feeding trial, liver and muscle tissues were collected for lipid (lipid content, lipid class, fatty acid composition) and H-1 NMR-based metabolomics analyses (aqueous and chloroform phases). Lipid analyses showed that fish fed ZYG diet had lower liver lipid content and thereby 10% higher level of docosahexaenoic acid compared with REF. Metabolomics analyses showed that on the one hand fish fed NY diet affected liver metabolites (2-3 fold higher concentrations of e.g., n,n-dimethylglycine and betaine) compared with REF, while, on the other hand, the muscle metabolic fingerprint was mainly a ffected by EY. In general, a ffected metabolites (e.g., alanine, anserine, betaine, hydroxyproline, isoleucine, malonate, n,n-dimethylglycine, proline, succinate, and valine) in fish fed test diets suggested that the test meal ingredients caused mainly a response in muscle metabolism. Fish metabolism was least affected by MM, which suggests that it may be suitable to replace fish meal in Arctic charr diets.
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| 6. |
- Al Banna, MH, et al.
(författare)
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Nutritional Value of Dry Fish in Bangladesh and Its Potential Contribution to Addressing Malnutrition: A Narrative Review
- 2022
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Ingår i: FISHES. - : MDPI AG. - 2410-3888. ; 7:5
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Forskningsöversikt (övrigt vetenskapligt/konstnärligt)abstract
- Understanding the linkage between the nutrient composition of foods and individuals’ recommended nutrient intake is important to address malnutrition. Despite it being a traditional and popular food item in Bangladesh, the nutrient composition of dry fish has not been reviewed yet. This study used a narrative review to assess the nutrient composition of dry fish and estimated its potential contribution to addressing some common nutritional deficiencies among children and pregnant and lactating women in Bangladesh. Records were collected from different databases, including the Web of Science, Google Scholar, PubMed, ScienceDirect, Banglajol, and ResearchGate. Data were extracted from 48 articles containing 1128 entries regarding nutrient composition. Most of the nutrient analyses estimated the proximate composition, whereas vitamin, mineral, amino acid, and fatty acid compositions were scarce in the literature. We found that dry fish has high protein and mineral content and could contribute highly to meeting the recommended nutrient intake of protein, iron, zinc, and calcium for children and pregnant and lactating women. The summarized nutrient composition data could be useful for further research to observe how dry fish could be best utilized to address malnutrition in Bangladesh. This narrative review recommends that further nutrient analysis, with emphasis on vitamin, mineral, and fatty acid compositions.
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| 7. |
- Axling, Johanna, et al.
(författare)
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Boldness in Zebrafish Larvae-Development and Differences between a Domesticated Lab Strain and Offspring of Wild-Caught Fish
- 2022
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Ingår i: Fishes. - : MDPI AG. - 2410-3888. ; 7:4
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Tidskriftsartikel (refereegranskat)abstract
- Zebrafish (Danio rerio) are becoming one of the most important model organisms in behavioural neuroscience. It has been shown repeatedly that different zebrafish strains show large behavioural differences. These divergent behavioural profiles may have a genetic basis, but environmental factors and previous experience are also known to greatly affect the behavioural phenotype of zebrafish. It could be expected that behavioural differences at the larval stage should be less affected by environmental factors and experience. In the present study, we screened larvae of zebrafish of the AB strain and offspring of wild-caught zebrafish for boldness, using an open field test. In order to follow the behavioural development, we studied larvae at the age of 5-, 7-, 12- and 30-days post fertilization (dpf). Behaviour, as well as behavioural development, clearly differed between the larvae of the different strains. Wild larvae showed larger total distance moved than AB larvae, both at light and dark conditions. These differences were already present at 12 dpf but became more pronounced with age. Wild larvae had a greater variance compared to AB larvae for most of the variables. We have previously shown that bold and shy adult zebrafish differ in the brain expression of dopamine and opioid receptors. The results of the current study show that wild larvae display significantly higher brain expression of drd2b than AB larvae at 30 dpf, a difference that could be related to differences in activity. We did not detect any differences in the expression of opioid receptors.
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| 8. |
- Boussard, Annika, et al.
(författare)
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No Sex-Specific Effects of Artificial Selection for Relative Telencephalon Size during Detour Learning and Spatial Discrimination in Guppies (Poecilia reticulata)
- 2023
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Ingår i: Fishes. - 2410-3888. ; 8:11
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Tidskriftsartikel (refereegranskat)abstract
- Over recent decades, substantial research has focused on fish cognitive evolution to increase our understanding of the evolution of the enormous diversity of cognitive abilities that exists in fishes. One important but understudied aspect of cognitive evolution is sexual dimorphism in cognitive abilities. Sex-specific variation in brain region morphology has been proposed to be an important mechanism in this context. However, it is also common to find sex-specific variation in behavior and cognition without associated differences in brain morphology among the sexes. The telencephalon is the major cognitive center in the vertebrate brain and variation in telencephalon size has been associated with variation in cognition. Here, we utilize recently developed guppy artificial selection lines with ca. 10% differences in relative telencephalon size to investigate whether similar responses to selection of the size of this region may affect cognitive abilities differently in males and females. To that end, we compared two ecologically relevant aspects of cognition, detour learning and binary spatial discrimination. We tested the significance of the interaction between telencephalon size and sex, and we found no sex-specific effects of evolutionary increases in telencephalon size in the cognitive abilities tested. This study indicates that no clear cognitive sex-specific effects occur in response to rapid selection of telencephalon size. We suggest that future research on sexual dimorphism in cognitive abilities in fish could use various cognitive tests and examine telencephalic sub-regions to gain a more comprehensive understanding of their evolution.
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| 9. |
- Chupani, Latifeh, et al.
(författare)
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Water Hardness Alters the Gene Expression Response and Copper Toxicity in Daphnia magna
- 2022
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Ingår i: Fishes. - : MDPI. - 2410-3888. ; 7:5
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Tidskriftsartikel (refereegranskat)abstract
- The influence of water hardness on copper (Cu) toxicity in Daphnia magna was studied using gene expression analysis. Exposing D. magna to Cu in water with increasing levels of hardness decreased the acute toxicity. Hardness did not affect the predicted Cu complexation. After 24 h, D. magna showed an increased level of genes related to metal homeostasis (mt) following exposure to 25 mu g Cu/L in hard water. Daphnids in soft and medium water responded to 25 mu g Cu/L by upregulation of antioxidant defense and mt genes, revealing oxidative stress as a mechanism of Cu toxicity in D. magna. D. magna exposed to 25 mu g Cu/L in soft water did not survive for 96 h. In contrast, those exposed to 25 mu g Cu/L in medium and hard water survived for 96 h with significantly higher levels of mt genes. The genes related to oxidative damage (heat shock protein and glutathione S-transferase) in these groups did not deviate from control levels, indicating the protective effect of hardness. Metallothionein genes were upregulated at 17 mu g Cu/L at both 24 h and 96 h. The expression of catalase and ferritin increased in this group in soft and hard water at 96 h. The protective effect of hardness (in the tested range) on survival was also observed at a concentration of 25 mu g/L. The results suggest metallothionein (A and B), catalase, and ferritin genes, as potential biomarkers for copper exposure in D. magna regardless of hardness.
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| 10. |
- Erlandsson, Ann, 1968-, et al.
(författare)
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Using qPCR to Identify Potential Effects of Thermal Conditions during Embryogenesis on Mitochondrial DNA Copy Number in Juvenile Brown Trout Salmo trutta
- 2024
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Ingår i: Fishes. - : MDPI. - 2410-3888. ; 9:4
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Tidskriftsartikel (refereegranskat)abstract
- Changes in the number, structure, and function of mitochondria during the early life stages of animals can play an important role for an organism's metabolic rate, growth, and health. Previous studies have shown that juvenile brown trout (Salmo trutta) subjected to elevated temperatures during the embryonic stage respond phenotypically with a reduced metabolic rate. The aim of this study was to explore if embryonic temperature affects the mitochondria content of young brown trout and as such explains the previously found differences in metabolic rates. Here, we optimize a quantitative PCR (qPCR) method for the mitochondria cytochrome c oxidase subunit I gene, and then use the method as a proxy for mitochondrial DNA content. We hypothesize that young trout subjected to elevated temperatures during the embryonic stage respond phenotypically with a reduced mitochondrial DNA content. To test this hypothesis, we subjected brown trout to either control ambient (4.4 +/- 1.5 degrees C) or elevated temperatures (7.1 +/- 0.6 degrees C) during embryogenesis. Subsequently, we extracted DNA from liver and white muscle tissue of juvenile brown trout from the two different incubation temperature treatments and successively optimized qPCR for mitochondrial DNA. We found that the amount of mitochondria DNA in liver tissue was 18 times higher than in white muscle tissue, but there was no significant difference in mitochondria content in liver or muscle tissue between brown trout exposed to elevated and ambient control temperatures during embryogenesis. We conclude that reduced metabolic rate is not likely associated with mitochondria DNA content. We also suggest that qPCR is a simple and cost-effective method to quantify mitochondria DNA in frozen and partly degraded tissue from different treatment groups and a useful proxy for identification of differences in mitochondria number.
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