Flatfish Research Articles

Complete mitochondrial genome sequence and phylogenetic analysis of the hybrid flat fish Platichthys stellatus (♀) × Platichthys bicoloratus (♂)

We report the complete mitochondrial genome of the hybrid flounder Platichthys stellatus (♀) × Platichthys bicoloratus (♂). The mitochondrial genome contained 13 protein-coding genes, 2 ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and 1 control region (D-loop), for a total length of 16,874 bp. The nucleotide composition of the heavy strand was 29.15% C, 26.99% A, 26.14% T, and 17.71% G. A maximum-likelihood phylogenetic analysis showed that the hybrid flat fish was a member of the same clade as P. stellatus (maternal inheritance). Our findings add to the extant data on the subfamily Pleuronecidae and provide insight into their molecular phylogeny and taxonomy.

Explosives leaking from dumped munition contaminate fish from German coastal waters: a reason for chronic effects?

BackgroundConventional munition dumped into the North Sea and the Baltic Sea close to the German coastline is corroding. A major concern is that biota, including fish, are negatively affected by toxic explosives leaking into marine environments. With the present study, we investigated fish living in close proximity to munition dumping sites for contamination and for signs of health impairments. The flat fish species common dab (Limanda limanda) was used as a model, since it lives in the vicinity of dumping sites and exhibits minor migratory activity. Since explosives are excreted via the bile, the bile fluids from dab were analysed. Further on we inspected the health status of the fish.ResultsDab caught in German coastal waters of the Baltic Sea and the North Sea were contaminated with explosives. Probably due to rapid metabolization, concentrations of the explosive 2,4,6-trinitrotoluene (TNT) were always below limit of detection, but its metabolites 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dinitrotoluene were detected in bile fluid up to 26.36 ng/ml and 95.91 ng/ml, respectively. Only few fish from the Baltic Sea were positive for the explosive HMX, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine with a maximum concentration of 0.89 ng/ml. Highest concentrations of TNT metabolites in bile fluid were detected in dab collected near the dumping site “Kolberger Heide” in the bay of Kiel (Baltic Sea). However, also dab from the North Sea were significantly contaminated with TNT metabolites.ConclusionsThe present study showed for the first time that fish living close to near shore munition dumping sites in the North Sea are contaminated with explosives. Various health indicators (body condition factors, externally visible fish diseases, parasites or liver anomalies) showed differences in health status between fish living in the North Sea and in the Baltic Sea, respectively. However, the health status of fish caught at the most contaminated site in the Baltic Sea was not worse compared to fish living in less contaminated areas. We conclude that fish living in the vicinity of dumping sites in the North Sea and the Baltic Sea can be significantly contaminated with explosives. However, obvious health impairments of the fish were not observed.

Environmental DNA complements scientific trawling in surveys of marine fish biodiversity

Abstract Environmental DNA (eDNA) metabarcoding is a method to detect taxa from environmental samples. It is increasingly used for marine biodiversity surveys. As it only requires water collection, eDNA metabarcoding is less invasive than scientific trawling and might be more cost effective. Here, we analysed data from both sampling methods applied in the same scientific survey targeting Northeast Atlantic fish in the Bay of Biscay. We compared the methods regarding the distribution of taxonomic, phylogenetic, and functional diversity. We found that eDNA captured more taxonomic and phylogenetic richness than bottom trawling and more functional richness at the local scale. eDNA was less selective than trawling and detected species in local communities spanning larger phylogenetic and functional breadths, especially as it detected large pelagic species that escaped the trawl, even though trawling detected more flat fish. eDNA indicated differences in fish community composition that were comparable to those based on trawling. However, consistency between abundance estimates provided by eDNA metabarcoding and trawl catches was low, even after accounting for allometric scaling in eDNA production. We conclude that eDNA metabarcoding is a promising method that can complement scientific trawling for multi-component biodiversity monitoring based on presence/absence, but not yet for abundance.

Integer Programming Application to Optimize Profit of Samarinda Special Souvenir Production


 
 
 
 Yulia's Amplang shop is one of the businesses engaged in the culinary field in the form of souvenirs typical of Samarinda City, namely Amplang. The amplang variants produced by this store include flat fish (original), shrimp, crab, squid and seaweed. Limitations and rising raw material prices make stores often experience difficulties in optimizing production profits. This study aims to determine the number of packages in one production process for each variant produced so as to obtain maximum profit. This study used the revised simplex method and then continued with the Branch and Bound Method, which is a method used to solve linear programming problems that produce solutions in integer form. From the analysis using this method, the optimal amount was obtained as many as 317 packages per production, including 144 flat fish flavors (original), 52 shrimp flavors, 34 crab flavors, 54 squid flavors and 33 seaweed flavors with the maximum profit obtained. namely Rp. 4,125,635. The application of this method resulted in an increase in profits of 5.53% or Rp. 216,103 in one production process compared to the previous company's profits.
 
 
 

First report of L1 cell adhesion molecule (L1CAM) in flat fish (Starry flounder): Molecular features and expression analysis

In this study, the starry flounder L1 cell adhesion molecule (L1CAM) sequence was obtained using next-generation sequencing, and the integrity of the sequence was verified by cloning and sequencing. First, the amino acid sequence was predicted using the cDNA sequence, and the gene was then identified through multiple sequence alignment analysis with related sequences and phylogenetic analysis. Thus, homogeneity was confirmed. The expression level of PsL1CAM (Platichthys stellatus L1CAM) mRNA in healthy starry flounder was detected in all tissues used in the experiment, and tissue- and gene-specific expression levels were confirmed. In addition, as a result of mRNA expression analysis after artificial infection with viral hemorrhagic septicemia virus (VHSV) and Streptococcus parauberis PH0710, significant expression changes and characteristics were confirmed following infection with VHSV and S. parauberis PH0710. After artificial infection with VHSV, the expression level of PsL1CAM mRNA was significantly upregulated in almost all major tissues of the starry flounder, whereas it was significantly downregulated in mucosal-associated lymphoid tissues, such as the gills and intestine. Infection with S. parauberis PH0710 significantly upregulated the expression of PsL1CAM mRNA in almost all major tissues of the starry flounder, whereas it was significantly downregulated in the heart after infection. Our results indicate that PsL1CAM may be involved in the host immune response to starry flounders.

Simultaneous detection of residues of 34 beta-lactam antibiotics in livestock and fish samples through liquid chromatography-tandem mass spectrometry.

β-Lactam is one of the widely used veterinary drugs, but simultaneous analytical methods for β-lactam on various animal foods have not been established. In this study, we aimed to detect 34 β-lactam antibiotics simultaneously in livestock samples (beef, pork, chicken, egg, and milk) by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Samples were extracted using phosphate buffer/acetonitrile or water/acetonitrile and then cleaned with 150mg of C18 and 900mg of MgSO4. The method showed acceptable recovery and repeatability of 66.1-119% and 1.5-26%, respectively. The method was employed to monitor 127 real samples from the domestic market to confirm its applicability, and no β-lactam residues were detected. It was also applied to other matrices (eel, flat fish, and shrimp) and showed acceptable recovery (62.1-120%) and repeatability (1.0-28%). The method is expected to improve the efficiency of monitoring veterinary drug residues in domestic livestock products and fishery foods.

Establishment of analysis method for the quantification of residues of halquinol and its metabolites in livestock and fishery products using liquid chromatography–tandem mass spectrometry

In this study, an analysis method was established for the quantification of residues of halquinol and its metabolites in livestock and fishery products using liquid chromatography–tandem mass spectrometry (LC–MS/MS). We selected beef, pork (muscle and fat), chicken, egg, milk, flat fish, eel, and shrimp as target samples for validation of the method owing to them being typical livestock and fishery products. Validation of the developed analysis method was performed using liquid chromatography–tandem mass spectrometry (LC–MS/MS) at three concentration levels (0.5, 1, and 2 × the maximum residue limits) following the Codex Alimentarius (CODEX) guidelines (CAC/GL 71–2009). For all samples, correlation coefficients (R2) exceeded 0.99, recoveries ranged between 75.59 and 119.36%, and coefficients of variation (CV) ranged between 1.39 and 28.66%, thus satisfying CODEX guidelines. In addition, inter-laboratory validation was conducted, and the resulting recoveries and CVs satisfied the CODEX guidelines; LOQ was established as 10 μg kg–1 for pig muscle and 5 μg kg–1 for the other samples. Therefore, the analysis method developed in this study can accurately and precisely screen for and quantify halquinol and its metabolites in livestock and fishery products.

Genetic characterization of fish, Cynoglossus lingua Hamilton, 1822 found in Chandipur Coast of Odisha using COI and Cytochrome b genes

Aim: In this study we characterized the fish Cynoglossus lingua collected from Chandipur Coast of Odisha using the mtDNA markers cytochrome c oxidase I (COI) and cytochrome b (Cyt-b) genes. Methodology: Samples of flat fish were collected from Balaramgadi fish landing center, Chandipur sea beach, Odisha coast. The collected specimens were initially identified based on the morphology using standard taxonomic keys. Molecular characterization was accomplished through PCR amplification of COI and Cyt-b genes. The sequences were subjected to BLAST analysis and aligned using Clustal W for homology mapping. Phylogenetic status was inferred by the neighbor-joining method using MEGA v7.0. Results: The taxonomic keys and the COI and Cyt-b gene sequences identified the specimens as C. lingua. The COI and Cyt-b gene sequences showed 98% and 99% sequence similarity with C. lingua isolate FMU.CIFRI.FF-7 COI gene (GenBank accession: MN889532.1) and the C. lingua isolate FM.CIFRI.CYTB.FF-7 Cyt-b gene (GenBank accession MT362541.1), respectively. Interpretation: The study supports the reliability of combining classical taxonomic approaches with molecular analysis using COI and Cyt-b genes for the identification of C. lingua. Key words: Cynoglossus lingua, COI gene, Cytochrome b gene, DNA barcoding, Molecular taxonomy

The application of tie-down gillnet to improve the capture of blackfin flounder (Glyptocephalus stelleri) in a sustainable way

In this study, experimental fishing trials were performed to quantitatively evaluate and compare the fishing performance of trammel nets, tie-down gillnets, and single gillnets used for catching blackfin flounder. A total of eight cruises performed at depths of 100–140 m in the waters near Yangyang, Gangwon-do, Korea. Fisheries laws in Korea currently restrict the use of trammel nets due to concerns about overfishing and bycatch. Tie-down gillnets have a support line that changes their stretched height, thus increasing their catch rate, and are an attractive alternative to trammel nets or single gillnets; unmodified gillnet. Due to a lack of quantitative evaluation of their fishing performance, the performances of these three types of gillnets quantitatively compared. The number and weight of fish, particularly blackfish flounder, caught by each net under similar circumstances were compared. Our results suggest that the fishing performance of trammel nets and tie-down gillnets is much higher than that of single gillnets. Compared to single gillnets, trammel nets performed better by 2.98 times and 2.45 times, in terms of the total number and weight of fish caught, respectively, and tie-down gillnets performed better by 2.09 times and 1.97 times, respectively. In addition, the bycatch rate of tie-down gillnet for immature blackfin flounder with the total length less than 20 centimeters was similar to single gillnet; single gillnet 17.5% of immature blackfin flounder, tie-down 20% of immature blackfin flounder, trammel net 62.5% of immature blackfin flounder. Given that many flat fish such as flounders fall out of the net during the fishing process after being stuck in single gillnets, fishermen hope to use trammel nets. However, the relatively high catch rate of trammel nets likely necessitates restrictions for their use. This study suggests that tie-down gillnets are an option for sustainable fishing practice given that they perform better than single gillnet and reduce bycatch of immature blackfin flounder when compared to trammel nets.

P9.21: Future Liver Remnant Volume Ratio Less Than 30% Is Not A Contraindication to Living Donor Right Hepatectomy

Background: The evidence for defining a safe remnant/total volume ratio(RTVR) for in living donors undergoing right hepatectomy for living donor liver transplantation (LDLT) is still not clear yet. The current practice of arbitrarily requiring an RTVR of at least 30% is based on the experience of early studies to keep donor safety. Recently, some centers reported that extended resection with RTVR less than 30% for living donor right hepatectomy but there is no consensus has been established for future remnant liver volume (FRLV) ratio limit. Herein, we describe out center’s experience for living donor right hepatectomy with RTVR < 30% and evaluate the outcomes of living donors with RTVR < 30%. Methods: We retrospectively reviewed the outcomes of 473 living donor right hepatectomy (LDRH) which performed at our institution from January 2010 to December 2020. We performed right hepatectomy for living donors with RTVR <30% under the following criteria; 1) Age ≤40 2) Preservation of MHV 3) No or Minimal fatty changes (<15%) 4) Flat fish shaped left hemiliver 5) RTVR > 25% and FRLV/ BW ≥ 0.45. The outcomes in these extended living donors were compared with those in living donors under conventional criteria. Results: The mean RTVR in extended group was 27.1 ± 1.2 % (range, 25.1-28.9). Posthepatectomy liver failure (PHLF) occurred in 50 donors (10.6%) and most cases were grade A except one case in conventional group and no clinically significant PHLF was not evident for these extended donor group. PHLF and major complications were not more frequent in living donor group with RTVR <30%. In multivariate only the event for major complications was associated with PHLF but RTVR less than 30% was related to PHLF. To adjust for between-group differences, donors with FLR ≤30% and >30% were matched based on baseline characteristics and overall complication rates and the incidence of PHLF were not different between the two groups. Conclusion: DRH under our extended criteria could be performed safely in donors with RTVR ratio <30% under our strict criteria when no other donors are available and our extended criteria might be helpful to expand donor pools without adverse effects on donor safety.

High Throughput Screening of Antimicrobial Resistance Genes in Gram-Negative Seafood Bacteria.

From a global view of antimicrobial resistance over different sectors, seafood and the marine environment are often considered as potential reservoirs of antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs); however, there are few studies and sparse results on this sector. This study aims to provide new data and insights regarding the content of resistance markers in various seafood samples and sources, and therefore the potential exposure to humans in a global One Health approach. An innovative high throughput qPCR screening was developed and validated in order to simultaneously investigate the presence of 41 ARGs and 33 MGEs including plasmid replicons, integrons, and insertion sequences in Gram-negative bacteria. Analysis of 268 seafood isolates from the bacterial microflora of cod (n = 24), shellfish (n = 66), flat fishes (n = 53), shrimp (n = 10), and horse mackerel (n = 115) show the occurrence of sul-1, ant(3″)-Ia, aph(3′)-Ia, strA, strB, dfrA1, qnrA, and blaCTX-M-9 genes in Pseudomonas spp., Providencia spp., Klebsiella spp., Proteus spp., and Shewanella spp. isolates and the presence of MGEs in all bacterial species investigated. We found that the occurrence of MGE may be associated with the seafood type and the environmental, farming, and harvest conditions. Moreover, even if MGE were detected in half of the seafood isolates investigated, association with ARG was only identified for twelve isolates. The results corroborate the hypothesis that the incidence of antimicrobial-resistant bacteria (ARB) and ARG decreases with increasing distance from potential sources of fecal contamination. This unique and original high throughput micro-array designed for the screening of ARG and MGE in Gram-negative bacteria could be easily implementable for monitoring antimicrobial resistance gene markers in diverse contexts.

Stingray (Neotrygon orientalis) population structure based on catch data in Nusantara Fishery Port (Pelabuhan Perikanan Nusantara/PPN) Brondong, Lamongan

Stingray is a type of fish included in the Elasmobranchii class that has high economic potential. This study aims to determine the sex ratio, growth rate, length-weight relationship, condition factor, mortality and exploitation rate of stingray (Neotrygon orientalis) in PPN Brondong, Lamongan. Samples N. orientalis collected every week starting from October 1, 2019 until January 2021 and weighed in total body weight (gram) and measured in total body length (cm) then sex was identified based on macroscopic characteristics of gonads. The results showed that the sex ratio of N. orientalis was 1.4 : 1. Length growth value (K) of male and female N. orientalis are 0.0285 and 0.0233, respectively, which show a slow growth time to reach the asymptotic length (K≤ 0.5). Based on the analysis of the relationship between length and weight, the results show that b value are 1.9394 and 2.2023 in male and female N. orientalis, respectively, which means length growth rate faster than weight growth (b&lt; 3, negative allometric). N. orientalis are included in the category of flat (thin) fish with condition factor values ranging from 0.2462-3.9227. The total, natural, and fishing mortality rate were 0.395, 0.177, and 0.218, respectively. The exploitation rate is 0.551 where the value has exceeded the optimum value 0.5, which means that N. orientalis landed at the PPN Brondong, Lamongan has indicated overfishing caused by excessive fishing activity.

Geometric morphometric analysis of flatfishes of Gopalpur-on-Sea, Odisha coast, India

Flat fishes are known for their uniqueness by possessing both eyes on one side of their body, either sinistral or dextral, and are an essential component of the food chain and food web. The present study reports the geometric morphometric (GM) analysis of five species of the family Bothidae, four species of the family Cynoglossidae, and four species of the family Soleidae collected from Gopalpur-on-Sea, Odisha coast to understand their shape variation. The GM analysis supplements the morpho-taxonomy to discriminate population, evident from the principal component analysis, canonical variates analysis, and discriminant function analysis. Landmarks-based GM can elaborate shape differences between species and provide a meaningful way to improve the visualization and quantification of these differences at the time of species identification.

Methodology for Evaluating the Cutting Force of Planar Technical Blades Used in Flatfish Processing

In the food industry, there are many varieties of technical blades with different contours as well as different cutting edge geometries. The evaluation of the ability of technical blades to separate (cut) animal tissues is not a simple task and is usually based on the evaluation of the cutting effects in a technological process. This paper presents a methodology for evaluating the cutting force of technical blades used in food processing. A specially made test stand with numerical control was used in the study. Its application enabled a comparison of cutting force values for four different cutting edge geometries of planar knives used in the skinning operation of flat fishes. A unique feature of the conducted research was the use of a relatively high cutting speed value of vf = 214 mm/s, which corresponded to the real conditions of this process carried out in the industry. Obtained test results allow unambiguously choosing the most advantageous variant of knife geometry from among four different variants used for the tests. The results showed a clear relationship between the cutting force value and the value of the tip angle of the blades tested: for blades with the lowest tip angle, the lowest cutting force values were obtained.

Changes in marine turbot (Scophthalmus maximus) epidermis and skin mucus composition during development from bilateral larvae to juvenile flat fish.

Alike other flat fish, marine turbot has the particularity that changes from larvae with bilateral symmetry to adult with asymmetry, in terms of the position of the eyes. As expected, the skin configuration of this species is also affected by the development and transformation suffered by fish during metamorphosis. In this context, changes in the epidermis of marine turbot were studied using conventional staining and histochemical techniques using six lectins (UEA-I, PNA, RCA-I, WGA, Con A and SBA). During development from larvae to juvenile (3-300 days post-hatching), the epidermis increased in both thickness and the number of cell layers. In fact, the simple cuboidal epithelium observed in larvae at day 3 already became stratified at days 10-12, which sequentially increase in thickness with fish development. Turbot epidermis is composed basically of four cell types: epithelial and mucous or secretory cells that are present through the development, and pigmented cells and a type that the authors described as club-like cells that appear during and post-metamorphosis. The Alcian blue-periodic acid Schiff (AB-PAS) histochemical method revealed the presence of neutral glycoconjugates in mucous and club-like cells at post-metamorphic stages of fish. Accordingly, lectin analysis showed mucous cells containing glycoproteins rich in fucose (UEA-I labelling) and glycoconjugates rich in the sequence galactose-N-acetyl galactosamine (PNA and RCA-I labelling) when this cell type appears. Interestingly, melanophores were observed in the dorsal epidermis of post-metamorphic juveniles. This type of cell contains a black-to-brown pigment that provides the skin the typical colour of this fish species. Changes in mucous coat composition were observed during fish development, which was attributed to different roles of the glycoconjugates.

Temperature appeared to be an effective factor on growth performance of diploid and triploid turbot, Scophthalmus maximus, during the early life stage

Turbot, Scophthalmus maximus, is an economically important flat fish species. Usage of triploid turbot in aquaculture and fisheries management has a potential of being advantageous due to sterility, flesh quality, and better growth. In the present study, hatchery and growth performance of diploid and triploid turbot at 16 °C and 21 °C were compared. Fertilization, hatching, and survival rates of both diploid and triploid groups were similar. Both diploid and triploid larvae exhibited similar body weight and length at the first 90 days post-hatch (dph). Weight and length of the groups reared at different temperatures were significantly differed from each other until 174 dph. At the end of the growth experiment, the mean length and weight of the triploids reared at 16 °C were significantly lower than rest of the groups, the mean length and weight of the triploids reared at 21 °C were significantly higher than the rest of the groups. The mean weight and length of the diploid groups reared at 16 °C and 21 °C were similar at the end of the experiment. Significant differences were observed between groups in terms of growth parameter indices. FCR of diploid groups were better compared to their triploid counterparts. Significant differences were detected among triploid turbot raised at different water temperatures in terms of specific growth rates, weight gain ratio, and length gain ratio. Water temperature appeared to be an important abiotic factor in grow-out phase of triploid turbot.

Biological responses and toxicopathic effects elicited in Solea senegalensis juveniles by waterborne exposure to benzo[a]pyrene

Polycyclic aromatic hydrocarbons (PAHs) are priority contaminants in coastal and estuarine ecosystems under anthropogenic pressure. Although PAHs tend to accumulate in the sediment, toxicity for benthic flat fish such as soles may be caused by PAHs released from the sediment to the water column. Within this context, the present investigation aims at recognizing toxicopathic effects elicited after waterborne exposure to benzo[a]pyrene B[a]P, a model individual PAH compound, in juvenile Solea senegalensis. Sole juveniles were exposed to various concentrations of waterborne B[a]P for 3 and 7 days. Brain, liver, gills and gonad were the target tissues selected to determine biochemical and lysosomal biomarkers, and histopathology. Biological responses and toxicopathic effects were consistent with B[a]P concentration and exposure time. From day 3, hepatic catalase inhibition indicated potential oxidative effects of B[a]P. At day 7, contaminant exposure produced hepatic glutathione-S-transferase induction at low concentrations and inhibition at higher levels, evidencing a bell-shaped response. A clear gradient in lysosomal membrane destabilisation was observed in relation with B[a]P concentrations. Histopathological lesions were more frequent at day 7 and at higher contaminant levels. It seems that environmentally relevant waterborne concentrations of B[a]P (1000 ng/l) would suffice to cause toxicopathic effects on sole juveniles in relatively short exposure times. In agreement, the Integrative Biological Response index (IBR/n) indicated a dose-dependent decline in health condition upon exposure to B[a]P (IBR/nHighB[a]P > IBR/nMidB[a]P > IBR/nLowB[a]P > IBR/nDMSO > IBR/nControl). Overall, changes in antioxidant enzymes activity, lysosomal biomarkers and gill and liver histopathology are responsive early-warning signs of health disturbance in sole juveniles exposed to waterborne PAHs.

Cytogenomics Unveil Possible Transposable Elements Driving Rearrangements in Chromosomes 2 and 4 of Solea senegalensis.

Cytogenomics, the integration of cytogenetic and genomic data, has been used here to reconstruct the evolution of chromosomes 2 and 4 of Solea senegalensis. S. senegalensis is a flat fish with a karyotype comprising 2n = 42 chromosomes: 6 metacentric + 4 submetacentric + 8 subtelocentric + 24 telocentric. The Fluorescence in situ Hybridization with Bacterial Artificial Chromosomes (FISH-BAC) technique was applied to locate BACs in these chromosomes (11 and 10 BACs in chromosomes 2 and 4, respectively) and to generate integrated maps. Synteny analysis, taking eight reference fish species (Cynoglossus semilaevis, Scophthalmus maximus, Sparus aurata, Gasterosteus aculeatus, Xiphophorus maculatus, Oryzias latipes, Danio rerio, and Lepisosteus oculatus) for comparison, showed that the BACs of these two chromosomes of S. senegalensis were mainly distributed in two principal chromosomes in the reference species. Transposable Elements (TE) analysis showed significant differences between the two chromosomes, in terms of number of loci per Mb and coverage, and the class of TE (I or II) present. Analysis of TE divergence in chromosomes 2 and 4 compared to their syntenic regions in four reference fish species (C. semilaevis, S. maximus, O. latipes, and D. rerio) revealed differences in their age of activity compared with those species but less notable differences between the two chromosomes. Differences were also observed in peaks of divergence and coverage of TE families for all reference species even in those close to S. senegalensis, like S. maximus and C. semilaevis. Considered together, chromosomes 2 and 4 have evolved by Robertsonian fusions, pericentric inversions, and other chromosomal rearrangements mediated by TEs.

Wolf Dietary Diversity in an Island Archipelago

Photo 1. Alexander Archipelago wolf (Canis lupus ligoni), Southeast Alaska, USA. This subspecies of wolf inhabits a vast island archipelago that is naturally fragmented by steep terrain and expanses of ocean. These elements contribute to variation in species distribution and assemblages between island and mainland areas of this region. Photo credit: Bjorn Dihle. Photo 2. An Alexander Archipelago wolf foraging in the intertidal zone, Pleasant Island, Alaska, USA. Despite the near absence of ungulates, wolves continued to occupy this small island (49 km2) during our study period. Marine mammals were the most prevalent diet category for wolves on Pleasant Island, with sea otters (Enhydra lutris) dominant and Stellar sea lions (Eumetopias jubatus) and harbor seals (Phoca vitulina) in small proportions. Photo credit: Bjorn Dihle. Photo 3. An Alexander Archipelago wolf after successfully acquiring a flat fish, Glacier Bay National Park and Preserve, Alaska, USA. Access to marine environments can provide a wider variety of forage species, with marine mammals, fish, and marine invertebrates available in the intertidal zone. Increased consumption of these species could be advantageous for wolves because of reduced handling times and risk, allowing wolves to forage individually. Photo credit: Jessie Klump. Photo 4. Alexander Archipelago wolf-tracks in the intertidal zone, Southeast Alaska, USA. Photo credit: Gretchen H. Roffler. Photo 5. The author (G. H. Roffler) collecting wolf scat samples, Bartlett River, Glacier Bay National Park and Preserve, Alaska, USA. Previous research efforts have described wolf diets by visual identification of prey remains in scat. This work demonstrates use of a novel method (DNA metabarcoding of fecal prey remains) that has improved the capacity to identify species and is applied here to 860 wolf scats collected during 2010–2018 across 12 Southeast Alaskan study sites. Photo credit: Natalie Dawson. These photographs illustrate the article “Metabarcoding of fecal DNA shows dietary diversification in wolves substitutes for ungulates in an island archipelago” by Roffler, G. H., J. M. Allen, A. Massey, and T. Levi. Ecosphere. https://doi.org/10.1002/ecs2.3297

The Role of Observation-Measurement Methods in the Surface Characterization of X39Cr13 Stainless-Steel Cutting Blades Used in the Fish Processing Industry.

In the modern fish processing industry, flat fishes play an important role. They are processed into a final product in the form of a fillet during the skinning operation, which is carried out on machines operating in automated production lines. These machines are usually equipped with a single planar cutting blade or a few of such blades. The high-efficiency skinning and industrial conditions cause rapid wear of the cutting edge of the blade, which is detrimental to the quality of the final product. One of the forms of renewing the cutting ability of these types of tools is the regeneration carried out with the use of precise traverse surface grinding. The results of this process must be carefully verified for determining its correctness and possible optimization of its parameters. The main goal of this article was to characterize the usefulness of a number of observational and measuring methods to evaluate the results of the technical blade regeneration process. In this work, a number of contemporary observation–measurement methods such as optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), optical profilometry (OP), and angle-resolved scattering (ARS), supported by image processing and analysis techniques, were analyzed. The authors focused on presenting the role of the abovementioned methods in the surface characterization of planar cutting blades made of X39Cr13 chromium martensitic stainless steel before and after the technological operation of flat-fish skinning. Additionally, the surface condition after the regeneration process carried out using the five-axis CNC (computerized numerical control) grinding machine was also assessed. Numerous results of surface observations, elemental composition microanalysis, high-accuracy surface microgeometry measurements, and quantitative and qualitative analysis confirming the possibility of using the proposed methods in the presented applications are presented.