Seawater Fish Species Research Articles

Lipid profile and health benefit of commonly consumed fresh water and sea water fish species in the population of Serbia

Background/Aim. Dietary intake of n-3 long-chain polyunsaturated fatty acids (LC-PUFA) is important in prevention and treatment of different diseases. In general population, the average intake of n-3 LC-PUFA is often significantly lower than recommended levels. Fish lipids are rich sources of these fatty acids, of which the most important are eicosapentaenoic (20:5 n-3, EPA) and docosahexaenoic (22:6 n-3, DHA) fatty acids. This study was designed to determine and compare fat, fatty acids and lipid quality indices in 10 commercial fish species available on the Serbian market, as well as relation between their price and nutritional value. Methods. Freshwater fish originated from the Danube River in the Belgrade Region, while seawater fish were mostly from the Adriatic Sea. A gas chromatography method was used to define fatty acids in 40 fish samples after lipid extraction. Cost-minimization analysis was conducted to assess the economic utility. Results. Seawater fish had a significantly higher value of flash lipid quality compared to the freshwater fish (p < 0.05). Value of hypercholesterolaemic fatty acids (OFA) for the freshwater group was 18.70 (17.40?21.30) while the seawater group had a similar range of values 18.90 (17.55?22.75). Hypocholesterolaemic fatty acids (DFA) also showed similar ranges for both groups: 68.80 (66?70.20) for freshwater and 68.40 (64.85?73.05) for seawater group. The ratio of DHA/EPA ranged from 1.8 for sardine samples and up to 10 for tuna samples, indicating that the amount of DHA in natural samples exceeds the amount of EPA in many cases. The values of atherogenic (AI) and thrombogenic index (TI) were lower than 1 for all analysed samples. Conclusion. Sardine and mackerel had the highest content of n-3 LC-PUFA and presented the least expensive sources of EPA and DHA. The low values of AI and TI obtained from studied fish indicate its benefits from a health point of view.

Valorization of By-Products from Commercial Fish Species: Extraction and Chemical Properties of Skin Gelatins.

Fish skins constitute an important fraction of the enormous amount of wastes produced by the fish processing industry, part of which may be valorized through the extraction of gelatins. This research exploited the extraction and characterization of gelatins from the skin of three seawater fish species, namely yellowfin tuna (Thunnus albacares), blue shark (Prionace glauca), and greenland halibut (Reinhardtius hippoglossoides). Characterization included chemical composition, rheology, structure, texture, and molecular weight, whereas extraction studies intended to reduce costly steps during extraction process (reagents concentration, water consumption, and time of processing), while maintaining extraction efficiency. Chemical and physical characterization of the obtained gelatins revealed that the species from which the gelatin was extracted, as well as the heat treatment used, were key parameters in order to obtain a final product with specific properties. Therefore, the extraction conditions selected during gelatin production will drive its utilization into markets with well-defined specifications, where the necessity of unique products is being claimed. Such achievements are of utmost importance to the food industry, by paving the way to the introduction in the market of gelatins with distinct rheological and textural properties, which enables them to enlarge their range of applications.

Molecular characterization of Edwardsiella tarda from different aquatic organisms using 16S ribosomal RNA and the outer membrane protein A

Event Abstract Back to Event Molecular characterization of Edwardsiella tarda from different aquatic organisms using 16S ribosomal RNA and the outer membrane protein A Saurabh Dubey1, Stephen Mutoloki1, Oystein Evensen1 and Hetron M. Munang'Andu1* 1 Norwegian University of Life Sciences, Norway Edwardsiella tarda is a member of the enterobacteriaceae that infects different host species inclusive of fresh and seawater fish species. The outer surface of this bacterium is made of different antigenic components such as fimbriae and pilli that form different serovars and serotypes in different fish species and ecosystems. The major challenge in vaccine production has been to find antigens that are cross protective against a wide range of E. tarda serotypes. Definitive identification of E. tarda isolates obtained from different aquatic organisms is a prerequisite to finding antigenic proteins with cross protective abilities across different serotypes. In this study, we used the 16S ribosomal RNA (16S rRNA) to characterize isolates obtained from striped catfish (Pangasianodon hypophthalmus) of India, California perch (Hyperprosopon ellipticum) and eel (Anguilla anguilla) from Taiwan. A collection of 16S rRNA sequences of E. tarda isolates from different aquatic organisms deposited in public databanks was used in the analysis as were sequence alignments of the outer membrane protein A (OmpA) from the different aquatic organism used to explore the possibility of using this gene as a cross protective antigen against different E. tarda serotypes. By comparing the 16S rRNA sequence alignments put together in this study, our findings show significant genetic interspecies and inter-geographical variations of E. tarda isolates from different aquatic organisms in different ecosystems in the world. Furthermore. Our findings show that combining 16S rRNA bacterial identification with sequence analysis of antigenic proteins for different bacterial strains could serve as an effective strategy for identifying the most effective antigenic proteins that are cross protective against different E. tarda serotypes. However, there is need to combine these molecular characterization studies with immunization studies in fish in order to demonstrate the effectiveness of this selection criteria of antigenic proteins for use in vaccine design. These finding will be presented and discussed in detail herein. Keywords: Edwardsiella tarda, molecular characterization, 16S ribosomal RNA, outer membrane protein, Aquatic Organisms Conference: AquaEpi I - 2016, Oslo, Norway, 20 Sep - 22 Sep, 2016. Presentation Type: Oral Topic: Aquatic Animal Epidemiology Citation: Dubey S, Mutoloki S, Evensen O and Munang'Andu HM (2016). Molecular characterization of Edwardsiella tarda from different aquatic organisms using 16S ribosomal RNA and the outer membrane protein A. Front. Vet. Sci. Conference Abstract: AquaEpi I - 2016. doi: 10.3389/conf.FVETS.2016.02.00047 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 May 2016; Published Online: 14 Sep 2016. * Correspondence: Dr. Hetron M Munang'Andu, Norwegian University of Life Sciences, Oslo, Norway, hetron.m.munangandu@nord.no Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Saurabh Dubey Stephen Mutoloki Oystein Evensen Hetron M Munang'Andu Google Saurabh Dubey Stephen Mutoloki Oystein Evensen Hetron M Munang'Andu Google Scholar Saurabh Dubey Stephen Mutoloki Oystein Evensen Hetron M Munang'Andu PubMed Saurabh Dubey Stephen Mutoloki Oystein Evensen Hetron M Munang'Andu Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Effects of recombinant growth hormone on growth factor and immune component levels in the cinnamon clownfish, Amphiprion melanopus

We investigated the regulatory effects of recombinant growth hormone (rGH) on growth and immunity in an ornamental seawater fish species, the cinnamon clownfish (Amphiprion melanopus). Cinnamon clownfish received intraperitoneal injections of rGH or saline at doses of 0.1 or 1 µg/g, weekly, for 12 weeks. At the end of the experiment, the rGH injection group exhibited the greatest total length (5.3±0.3 and 5.6±0.2 cm, respectively, for the two doses). Moreover, after injection of rGH, the expression levels of pituitary GH mRNA and liver insulin-like growth factor I (IGF-I) mRNA increased significantly (by 18.9-fold and 5.7-fold, respectively), as assessed by quantitative real-time polymerase chain reaction, while the splenic levels of immunoglobulin M protein increased significantly (by 10.5-fold) as assessed by Western blot analysis. Plasma lysozyme and melatonin levels also increased by 2.1- and 1.37-fold, respectively, over those of the control group. Plasma alanine and aspartate aminotransferase levels at 12 weeks (764±46.4 and 3002±101.2 IU/l, respectively) were significantly higher than those at baseline; however, treatment with rGH decreased these values at 12 weeks (276±30.4 and 600.5±59.2 IU/l, respectively). These findings support the hypothesis that rGH plays important roles in the regulation of the GH–IGF-I axis for growth and immunity in the cinnamon clownfish.

Characterization of alpha-2-macroglobulin from groupers

Alpha-2-macroglobulin (α-2-M) is a protease inhibitor broadly present in the plasma of vertebrates and invertebrates, and is an important non-specific humoral factor in defence system of the animals. This study conducted the immuno-analysis and mass spectrometric analysis methods to investigate the characteristics of the protease inhibitor, α-2-M, among groupers and related species. Rabbit antiserum to the purified α-2-M of Epinephelus coioides was used in different immunological methods to determine the immune cross-reactions of the α-2-M in samples. Plasma of Epinephelus bruneus, Epinephelus fuscoguttatus, Epinephelus lanceolatus, and Epinephelus quoyanus exhibited high protease inhibitory activities by BAPNA-trypsin assay. To purify the α-2-M protein, plasma protein of grouper E. coioides was first precipitated by using PEG 6000, then Blue Sepharose 6 Fast Flow, DEAE Sephacel, Con A Separose 4B and Phenyl Sepharose High Performance columns were used on FPLC system for purification. The molecular mass of grouper plasma α-2-M was determined as a 180 kDa protein on non-reduced SDS-PAGE. In addition, it was determined as 97 and 80 kDa protein on reduced SDS-PAGE. Enzymatic and chemical deglycosylation of glycogen revealed that the contents of glycogen in 97 and 80 kDa subunits were 12.4% and 15%, respectively, and were all belonging to N-linked type.Only one precipitation arc was visualized in all plasma of Epinephelus spp. using the rabbit antiserum to the purified α-2-M of E. coioides, on crossed immunoelectrophoresis (CIE) gels. The plasma of Epinephelus spp. and seawater fish species showed stronger responses than freshwater fish species while that of other animal species showed no response by dot-blot assay. One single band was detected on Native PAGE-Western blotting assay, one single 180 kDa band was detected on non-reduced SDS-PAGE-Western blotting, and four bands (80, 97, 160, 250 kDa) were detected on reduced SDS-PAGE when various grouper plasma was performed respectivity. However, no band was detected using plasma from the freshwater fish species and other animal species. Thus, further indicates that the protein structure of α-2-M of Epinephelus spp. was closely related among seawater fish species. In addition the identity of the two subunits was identified using LC/MS/MS which was similar to α-2-M of grass carp (Ctenopharyngodon idella) and bluegill sunfish (Lepomis macrochirus) on the protein hit.

A novel respirometer for online detection of metabolites in aquaculture research: Evaluation and first applications

In this study we describe a novel flow-through respirometer with automated and semi-continuous detection of key water variables. The recirculating aquaculture system was designed to house aquatic organisms in culture-like conditions and allow long-term, high-precision measurements. Nine respirometry tanks (250L in volume each) housed animals, and a tenth (without animals) acted as a reference tank. A single measurement unit made sequential measurements of each tank to eliminate the problem of sensor variation associated with multi-probe setups. The accuracy of the analyzers in relation to measurement range was: O2=1%; CO2<1%; NH3=2%; temperature ≤ 0.25%; and pH±0.01. Dissolved CO2 was measured using air–water equilibration coupled with non-dispersive infrared detection of carrier gas, and NH3 was quantified using a reagent-based assay and spectophotometric autoanalyzer. Though expensive and not common in aquaculture or physiology research, these two automated metabolite analyzers could operate in both fresh and seawater, and offered high precision and accuracy. We report on the performance of these instruments for aquaculture research in two trials using a freshwater (rainbow trout, Oncorhynchus mykiss) and seawater fish species (turbot, Scophthalmus maximus). One of the main constraints imposed by the sequential measurement of multiple tanks was the measurement frequency of each tank. In the aforementioned system, NH3 analyzes took the longest (12min), followed by CO2 (7min), O2 (6min), and pH (3min).

Complete Genome Sequence of the European Sheatfish Virus

Viral diseases are an increasing threat to the thriving aquaculture industry worldwide. An emerging group of fish pathogens is formed by several ranaviruses, which have been isolated at different locations from freshwater and seawater fish species since 1985. We report the complete genome sequence of European sheatfish ranavirus (ESV), the first ranavirus isolated in Europe, which causes high mortality rates in infected sheatfish (Silurus glanis) and in other species. Analysis of the genome sequence shows that ESV belongs to the amphibian-like ranaviruses and is closely related to the epizootic hematopoietic necrosis virus (EHNV), a disease agent geographically confined to the Australian continent and notifiable to the World Organization for Animal Health.

Simple Extraction and Rapid HPLC Method for Tocopherol Analysis in Marine and Fresh-water Fish Species

A rapid high-performance liquid chromatographic (HPLC) method with simple extraction procedure for the determination of tocopherols in seafood was developed. A continuous isocratic elution system was used for the analysis with a mixture of acetonitrile and methanol. Tocopherols were identified by comparison of retention times and peak area values with standard of α-, β-, γ- and δ-tocopherols. The HPLC technique used showed good performance parameters (linearity r2 = 0.9999, and relative standard deviation (RSD) ≤ 12.38%). The total recoveries for each tocopherol were 99.7, 99.9, 99.8 and 99.7% for α, β, γ- and δ, respectively. This method was then applied to freshwater and seawater fish species to detect their tocopherol contents. Significant differences (P < 0.05) were observed in the content of tocopherol among fish species. The highest content was obtained from shrimp (81.3 mg/kg), while the lowest was found for whiting (9.8 mg/kg).

Fatty acid profiles and fat contents of commercially important seawater and freshwater fish species of Turkey: A comparative study

The fat content and fatty acid compositions of edible muscle of commercially important seawater and freshwater fish species were investigated. The fatty acid compositions of seawater fish species were found to be 25.5–39.4% saturated (SFA), 13.2–29.0% monounsaturated (MUFAs) and 25.2–48.2% polyunsaturated acids (PUFAs), whereas the fatty acid compositions of freshwater fish from Lake Seyhan consisted of 28.0–34.6% saturated (SFA), 10.7–22.7% monounsaturated (MUFAs) and 23.2–43.7% polyunsaturated acids (PUFAs). The proportions of n3 PUFAs of seawater fish (ranging from 22.6 for waker to 44.2% for blue fish) were higher than those of n3 PUFAs of freshwater fish (ranging from 11.5% for North African catfish to 28.4% for zander). However, the levels of n6 PUFAs of seawater fish (ranging from 0.43% for blue fish to 14.4% for sea bass) were lower than those of n6 PUFAs of freshwater fish (ranging from 5.27% for kutum to 16.8% for tench). The results showed that fatty acid profiles of most freshwater fish are basically comparable to those of seawater fish as sources of PUFAs.

Sperm motility in fishes. I. Effects of temperature and pH: a review

Sperm motility is a key factor in allowing us to determine semen quality and fertilizing capacity. Motility in semen is mainly controlled by K+ in salmonids, and probably also in sturgeons, and by osmotic pressure in other freshwater and seawater fish species, but other factors, such as concentration of surrounding metabolites and ions (Ca2+, Mg2+, etc.), pH and temperature also influence motility characteristics. In the present study, we have mainly reviewed and summarized the effects of temperature and pH on the motility of spermatozoa in three fish species: salmonids, cyprinids and sturgeons. Data in the literature show that motility, fertilizing ability and velocity of spermatozoa, as well as the duration of the motility period, depend on the temperature of the assay medium and also of that of the brood fish holding tank. In contrast, the pH of the swimming medium, and thus the intracellular pH of spermatozoa, has less influence on sperm motility parameters in cyprinids, salmonids and sturgeons.

The immune system of sea bass, Dicentrarchus labrax, reared in aquaculture

The sea bass Dicentrarchus labrax is one the most important seawater fish species of south Europe and Mediterranean aquaculture, and studies on its immune system are important for both scientific and applied purposes. In this paper, we summarise the results obtained in studies of the immune system in this species, and present original data on cell-mediated acquired immune response.

汚染物質毒性評価のための指標海産魚選定

In order to evaluate toxicities of pollutants to seawater fish, we examined suitable fishes for acute toxicity test. Larvae and juveniles of seven seawater fish species which are easy to rear or collect, were exposed to cadmium (Cd) and fenitrothion (MEP) for 96 hours.While we could not calculated 72 and 96h LC50 of larvae because of their mortality of control over 10% after 48 hours, all early juveniles showed incipient LC50s or 96h LC50s. Based on the incipient LC50 or 96h LC50, the order of the LC50 of each fish to the pollutants were the following.1) Cd: C. dolichognathus >G. punctata >A. schlegeli >M. cephalus >E. japonica >P. major2) MEP : C. dolichognathus >M. cephalus, P. olivaceus >G. punctata >P. major >A. schlegeliThe red sea bream (P. major) showed the lower incipient LC50s of Cd and MEP in 163mg and 510mg body weights, respectively. Based on the sensitivity to the pollutants by incipient LC50 or 96h LC50 and its availability, the early juvenile of red sea bream is considered the best among the fishes examined for acute toxicity test.