Non-lethal sampling for the stable isotope analysis of the critically endangered European eel Anguilla anguilla: how fin and mucus compare to dorsal muscle.
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ABSTRACT:
SUBMITTER: Boardman RM
PROVIDER: S-EPMC9303185 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:European eel (Anguilla anguilla) is a critically endangered species requiring CITES permits for international trade. Despite the fact that no imports to Hong Kong were declared within the last 2 years, our study found that this species is still commonly sold in major supermarket chains across Hong Kong. In a COI barcoding survey of 49 retail vendors encompassing 13 brands, 9 of 13 carried A. anguilla, and 45% of all eel products available at retail outlets (n = 49) were unambiguously identified as A. anguilla. Considering the visual similarity of eel species and disproportionate amount of undeclared A. anguilla available for consumption, this finding raises urgent concerns regarding the enforcement of international CITES trade regulations. Furthermore, the prevalence of A. anguilla in supermarkets highlights how illicit wildlife products are not solely limited to specialized affluent buyers; some species have entered mainstream distribution networks for the average consumer.
| S-EPMC7056311 | biostudies-literature
Project description:Anguillid herpesvirus 1 (AngHV) is an important viral pathogen affecting eel. This study was designed to investigate the potential molecular mechanisms and immune response elicited at the protein levels in the skin mucus of AngHV-infected Anguilla anguilla. Tandem mass tag (TMT)-labelling proteomics with the liquid chromatography tandem mass spectrometry (LC-MS/MS) was used for performing quantitative identification of the proteins. In addition, the quantitative protein amount was detected by parallel reaction monitoring (PRM) analysis. A total of 3486 proteins were identified, of which 2935 were quantified. When a protein fold change was greater than 1.3 or less than 0.76, it indicated a differentially expressed protein (DEP). Overall, 187 up-regulated proteins and 126 down-regulated proteins were detected, and most of the DEPs were enriched in the CAMs pathway, intestinal immune pathway, herpes simplex virus 1 infection pathway, phagosome pathway and p53 signaling pathway. The results of the DEPs detected by PRM were highly consistent with the results of the TMT-labelled quantitative proteomic analysis. The findings of this study provide an important research basis for further understanding the pathogenesis of AngHV.
| S-EPMC9570476 | biostudies-literature
Project description:This article describes the data of raw material compositions for formulating the diet for Indonesian short-fin eel, Anguilla bicolor Anguilla bicolor McClelland, 1844 elver. The data on growth performance, survival and feed utilization of eel elver from the formulated diet test results are also presented here. Four formulated diets and one commercial feed were tested for the eel elver. The formulated diet was formulated from animal and plant based protein sources such as; fish meal, cornmeal, soybean meal, fine bran, ebi-shrimp meal, golden snail meal, bloodmeal, and tapioca flour. Vitamins and minerals were added into the diet. In addition, probiotics and papain enzyme and its combination were also included into the experimental diets to boost the growth performance, survival and feed utilization of the fish. The tested treatments were; (A) commercial diet without probiotic and papain enzyme, (B) experimental diet without probiotic and papain enzyme, (C) experimental diet with probiotic 10 ml kg-1 feed, (D) experimental diet with papain enzyme 10 g kg-1 feed, (E) experimental diet with probiotic 10 ml kg-1 + papain 10 g kg-1 feed, (F) experimental diet with probiotic 5 ml kg-1 + papain 5 g kg-1 feed. Each experimental fish group was fed on an experimental diet twice a day at 08.00 AM and 06.00 PM at feeding level of 10% body weight for 60 days. The results showed that the weight gain ranged between 4.60 g to 5.92 g, daily growth rate between 0.063 g day-1 and 0.098 g per day-1, the specific growth rate varies from 0.72% day-1 to 1.35% day-1, survival rate 50.00% to 73.33%, feed conversion ratio from 2.35 to 4.17, and feed efficiency between 41.82% to 58.98%. The best treatment was found in fish fed on the experimental diet with papain enzyme 10 g kg-1 of feed.
| S-EPMC7182714 | biostudies-literature
Project description:Anguillid herpesvirus 1 (AngHV) is an important viral pathogen of eel. This study was conducted to investigate the molecular mechanisms and immune response at the protein levels in the skin mucus of AngHV infected Anguilla anguilla. TMT-labelling proteomics with the liquid chromatographytandem mass spectrometry (LC-MS/MS) was used for protein quantitative identification. And the quantitative protein amount was detected by parallel reaction monitoring (PRM) analysis. A total of 3486 proteins were identified, of which 2935 were quantified. When a protein fold change greater than 1.3 or less than 0.76 was considered to indicate a differentially expressed protein (DEP), 187 up-regulated proteins and 126 down-regulated proteins were detected, and most of the DEPs were enriched in CAMs pathway, intestinal immune pathway, herpes simplex virus 1 infection pathway, phagosome pathway and p53 signaling pathway. The results of the DEPs detected by PRM were highly consistent with that of the TMT-labelled quantitative proteomic analysis results.
2023-03-10 | PXD034867 | Pride
Project description:The analysis of transcriptomes is well-established and increasingly affordable in studies at the interface of ecology and evolution. Expression analysis of thousands of genes in parallel reveals functions and pathways involved in relevant phenotypic differentiation. The application of such methods typically involves the sacrifice of the analysed organisms, which is potentially subject to ethical and legal constraints. As an alternative to lethal sampling, transcriptome analyses can be performed using small biopsies of dispensable tissues. It has to be verified, however, to what extent such results are representative of the whole organism. Here, we use a custom microarray to compare transcriptomes of tail-clip samples with those of the remaining whole-body of fire salamander larvae (Salamandra salamandra). The microarray was calibrated using target RNA to validate the performance of each probe. We varied water temperature to test whether the thermal response in gene expression can be characterized in both types of sample. A large fraction (51 %) of the differentially expressed genes showed parallel changes for both tail clips and whole bodies in response to temperature. While sets of differentially expressed were not identical, they largely belonged to the same functional categories. The gene functions thus revealed a common thermal response of larvae irrespective of the sampled tissue. This included an overexpression of mitochondrial transcripts, an expected thermal acclimatization response of ectotherms. Hence, ecological transcriptomics based on small biopsies represent an alternative to the analysis of lethally sampled tissues in situations where the sacrifice of individuals is not an option.
2015-06-20 | GSE70054 | GEO
Project description:BACKGROUND: Studies on artificial hybridization of different Anguilla species were conducted recently, i.e. female A. australis with male A. dieffenbachii, and female A. japonica with male A. anguilla. The existence of these artificial hybrids was however not demonstrated by independent genetic methods. Two species - A. anguilla and A. australis - that are phylogenetically close but have different sexual maturation times (12-25 weeks and 6-8 weeks, respectively), were expected to produce favourable hybrids for reproduction studies. RESULTS: A modification of the protocol for the reproduction of Anguilla japonica was used to produce eight-day Anguilla australis larvae, with a success rate of 71.4%. Thus ten out of 14 females produced eggs that could be fertilized, and three batches resulted in mass hatching. Hybrid larvae from female A. australis x male A. Anguilla survived for up to seven days post fertilization (dpf). The early development of the hybrid showed typical characteristics of A. anguilla tail pigmentation at 50 hours post fertilization (hpf), indicating expression of genes derived from the father. CONCLUSIONS: In this paper we describe the first production of hybrid larvae from male A. anguilla and female A. australis and their survival for up to 7 dpf. A species-specific nucleotide difference in the 18 S rDNA gene confirmed that genes from both A. australis and A. anguilla were present in the hybrids. The developmental stages of the hybrid eel embryos and larvae are described using high resolution images. Video footage also indicated a heart beat in 5-dpf larva.
| S-EPMC3063818 | biostudies-literature
Project description:The analysis of transcriptomes is well-established and increasingly affordable in studies at the interface of ecology and evolution. Expression analysis of thousands of genes in parallel reveals functions and pathways involved in relevant phenotypic differentiation. The application of such methods typically involves the sacrifice of the analysed organisms, which is potentially subject to ethical and legal constraints. As an alternative to lethal sampling, transcriptome analyses can be performed using small biopsies of dispensable tissues. It has to be verified, however, to what extent such results are representative of the whole organism. Here, we use a custom microarray to compare transcriptomes of tail-clip samples with those of the remaining whole-body of fire salamander larvae (Salamandra salamandra). The microarray was calibrated using target RNA to validate the performance of each probe. We varied water temperature to test whether the thermal response in gene expression can be characterized in both types of sample. A large fraction (51 %) of the differentially expressed genes showed parallel changes for both tail clips and whole bodies in response to temperature. While sets of differentially expressed were not identical, they largely belonged to the same functional categories. The gene functions thus revealed a common thermal response of larvae irrespective of the sampled tissue. This included an overexpression of mitochondrial transcripts, an expected thermal acclimatization response of ectotherms. Hence, ecological transcriptomics based on small biopsies represent an alternative to the analysis of lethally sampled tissues in situations where the sacrifice of individuals is not an option. Larvae of European Fire salamander were exposed to two different temperatures (9°C & 17°C; n(cold) = 6, n(warm) = 6, n(total) = 12). The transcriptome response to temperature was assessed based on RNA extracted from tail tips, which can be sampled without sacrificing the individual, and based on RNA extracted from the remaining whole body. Results from the analysis of both tissues were compared.
2015-06-20 | E-GEOD-70054 | biostudies-arrayexpress
Project description:This study reports on the first observation of a spontaneously matured female European eel. The 43-year-old eel, together with eleven other females, resided at an aquarium house since their capture in 2002 and stocking as glass eels in 1978. In June 2019, the girth of the belly of the female increased as a sign of oocyte maturation. The specimen had an estimated gonadosomatic index (GSI) of 47, only half of the oocytes were hydrated and matured, indicating that European eels are polycyclic batch spawners. The live eels of the cohort were still in the previtellogenic phase but their eye sizes were close to that of the matured eel. We hypothesize that substances released by other maturing and spawning fishes may have triggered puberty of the eel. This first observation, and the possibility of more eels maturing in the near future, provides a natural reference for the sexual maturation of the European eel.
| S-EPMC7012921 | biostudies-literature
Project description:In this work, we used the eel (Anguilla anguilla) as an animal model to test the hypothesis of Barr et al. (2013a,b) about the putative role of the epidermal mucosa as a phage enrichment layer. To this end, we analyzed the microbial content of the skin mucus of wild and farmed eels by using a metagenomic approach. We found a great abundance of replicating phage genomes (concatemers) in all the samples. They were assembled in four complete genomes of three Myovirus and one Podovirus. We also found evidences that ΦKZ and Podovirus phages could be part of the resident microbiota associated to the eel mucosal surface and persist on them over the time. Moreover, the viral abundance estimated by epiflorescent counts and by metagenomic recruitment from eel mucosa was higher than that of the surrounding water. Taken together, our results support the hypothesis that claims a possible role of phages in the animal mucus as agents controlling bacterial populations, including pathogenic species, providing a kind of innate immunity.
| S-EPMC4310352 | biostudies-literature
Project description:BackgroundOnce highly abundant, the European eel (Anguilla anguilla L.; Anguillidae; Teleostei) is considered to be critically endangered and on the verge of extinction, as the stock has declined by 90-99% since the 1980s. Yet, the species is poorly characterized at molecular level with little sequence information available in public databases.ResultsThe first European eel transcriptome was obtained by 454 FLX Titanium sequencing of a normalized cDNA library, produced from a pool of 18 glass eels (juveniles) from the French Atlantic coast and two sites in the Mediterranean coast. Over 310,000 reads were assembled in a total of 19,631 transcribed contigs, with an average length of 531 nucleotides. Overall 36% of the contigs were annotated to known protein/nucleotide sequences and 35 putative miRNA identified.ConclusionsThis study represents the first transcriptome analysis for a critically endangered species. EeelBase, a dedicated database of annotated transcriptome sequences of the European eel is freely available at http://compgen.bio.unipd.it/eeelbase. Considering the multiple factors potentially involved in the decline of the European eel, including anthropogenic factors such as pollution and human-introduced diseases, our results will provide a rich source of data to discover and identify new genes, characterize gene expression, as well as for identification of genetic markers scattered across the genome to be used in various applications.
| S-EPMC3012609 | biostudies-literature