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During the past decade, a lot of study has been conducted in the favor of biomimicry and its applications in our daily lives. Fish scales, specifically, are being investigated with quite a lot of detail, and there are several species which possess an impressive mechanical property when under impact loadings and these impact loadings are naturally observed on the fish scale of the prey by the sharp teeth of predator fish when under attack. Considering such a reputation of fish scales, this article provides a concise look into the structural dependability of a fish scale from a species called Arapaima Gigas, which is a freshwater fish species found in the Amazon River. [ABSTRACT FROM AUTHOR]

The utilization of biowaste fillers in the development of high-density polyurethane (PU) foams has gained significant attention due to environmental and economic benefits. This study investigates the mechanical properties of PU foams reinforced with biowaste fillers extracted from fish scales (FS) and fish scale-derived collagen (FSC). The fish scales and collagen were characterized for their composition and integrated into PU foams at various loadings. Mechanical properties such as tensile strength, hardness, and density were evaluated. ANOVA was used to analyze the mean values. Bonferroni tests were used to identify differences between the filler materials (α = 0.05). The tensile strength increases with an increase in filler content for both FS (59.48 Kpa) and FSC (65.43 Kpa). No differences were observed between FS and FSC in tensile strength. Significant differences were observed between the FS and FSC in both hardness and density (p < 0.001). The results demonstrated that both fillers enhanced the mechanical properties of PU foams, with collagen-reinforced foams showing superior performance. This suggests that collagen and fish scales can be effective biowaste fillers for developing environmentally friendly PU foams with enhanced mechanical properties. [ABSTRACT FROM AUTHOR]

The discharge of solid waste from various industrial units and its associated release of nutrient-rich wastewater affects aquatic ecosystem. Therefore the current study was undertaken to provide a first report about the adsorption potential of thermally modified fish scale adsorbents such as Dehydrated Fish scales (DFS), Fish Scale Biochar (FSB) and Activated Fish Scales (AFS) in reducing the concentration of nitrites, nitrates and ammonium ions in drain water. Prepared adsorbents were characterized with different analytical techniques such as FTIR, TGA, SEM, EDX and XRD. Adsorption capacities of adsorbents were examined as batch work by altering adsorbent dose, contact time and pH levels. Among the adsorbents, DFS exhibited significant (P < 0.05) and maximum removal percentage of nitrite (24.46%) and nitrate (26.18%) ions at 60 min contact time with 0.06 g dose level. About 33% reduction of ammonia was recorded in pH 10 using 0.12 g FSB at 60 min contact time. The experimental data fitted well with Langmuir isotherm and pseudo-second order models with maximum coefficient of determination (R2) values (> 0.95). Influence of intra-particle diffusion resistance on adsorption of pollutants showed lower R2 values (0.600–0.806) than other kinetic parameters. The thickness of boundary layer was determined (0.5—2.6 mg/g) for the prepared adsorbents. The economic feasibility of adsorbents used in this study (0.012 – 1.72 USD) was also calculated and compared with commercial activated carbon (1.82 USD). This study confirms that waste fish scales can be effectively employed as cost effective and eco-friendly adsorbents in the treatment of nitrogenous pollutants in wastewater. [ABSTRACT FROM AUTHOR]

Abstract Fish scales, considered as low-value by-products, contain peptides and hydroxyapatite that can be applied to produce peptide chelated calcium directly. This study developed a sustainable and one-pot fabrication method for the peptide-chelated calcium from fish scale hydrolysates (FSP-Ca). During pepsin hydrolysis, the releases of peptides (FSP), calcium, and phosphate from fish scales occurred simultaneously, and the chelation was also effectively performed. After a 6-h hydrolysis, the yield of FSP was 46.18%, and the dissolution rate of calcium was 49.53%. Under the optimal conditions (pH 7, chelation time of 25 min, and chelation temperature of 48 °C), a high chelation rate of 86.16% was obtained, with a calcium content of 81.8 mg/g. The results of UV absorption, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the successful chelation between FSP and calcium derived from fish scales. The –NH2, –COO–, N–H, C=O, C–H, and –OH groups in FSP participated in the formation of FSP-Ca. Graphical Abstract

Fish are the most edible protein source worldwide and generate several remnants such as scales, viscera, head, bone, and skin. Fish wastes are not disposed of properly, which adversely affects the environment, especially the water bodies where fish processing industries dispose of their waste. Fish waste mainly contains nitrogen, oil, fat, salts, heavy metals, and organic compounds, which increase the biological oxygen demand and chemical oxygen demand. Fish waste can degrade in various ways, such as physicochemical or by enzymatic action, but using microbes is an environmentally friendly approach that can provide valuable compounds such as products such as collagen, chitin, minerals, and fish protein concentrates. This review is designed to focus on the suitability of microbes as tools for fish waste degradation and the production of certain associated. This study also provides insight into the production of other compounds such as protease, chitinase, and chitin applicability of these products. After processing, fish waste as a microbial growth media for enzyme production since microorganisms synthesize enzymes such as proteases, protein hydrolysates, lipids, and chitinase, which have broader applications in the pharmaceutical, cosmetic, biomedical material, and food processing industries. [ABSTRACT FROM AUTHOR]

Chitosan (CS) can be extracted from waste fish scales through a series of chemical processes, including demineralization, deproteinization, and deacetylation. The biomaterial poly (acrylamide [AM]‐co‐acrylic acid [AA])/CS is a unique superabsorbent material synthesized through the free radical graft copolymerization method by using AM, AA, and CS powder. During synthesis, ammonium persulfate is used as an initiator, and N, N′‐methylene bisacrylamide is used as a cross‐linker. Scanning electron microscopy and Fourier transform infrared spectroscopy have been studied to know about the morphology and structure of the synthesized superabsorbent materials. The water absorbency of the material continuously increases from day 1 to day 30. The thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG) of the superabsorbent material show adequate thermal stability. The X‐ray diffraction (XRD) analysis indicates that the synthesized biomaterial is virtually amorphous in nature. The percentage of biodegradability increases with time. The encapsulation efficiency of amoxicillin drugs is around 70%, which indicates that the biomaterial is highly efficient for drug release applications. The synthesized novel biomaterial is a low‐cost, eco‐friendly, and thermally stable hydrogel that can be effectively used in drug release applications. Highlights: Chitosan (CS)‐based hydrogels are highly pH‐sensitive towards drug release.The biodegradability and swelling behavior of the synthesized biomaterial were studied by adopting a suitable methodology.The novel material formed was characterized by using Fourier transform infrared spectroscopy, TGA, and Scanning electron microscopy. The encapsulation efficiency, kinetic study, and controlled drug release behavior of the amoxicillin drug were studied in solutions of simulated gastric fluid and phosphate‐buffered saline.The material developed in this study shows good performance in controlled drug delivery, and is therefore suitable for manufacturing medical devices used in drug delivery. [ABSTRACT FROM AUTHOR]

Fish scales, considered as low-value by-products, contain peptides and hydroxyapatite that can be applied to produce peptide chelated calcium directly. This study developed a sustainable and one-pot fabrication method for the peptide-chelated calcium from fish scale hydrolysates (FSP-Ca). During pepsin hydrolysis, the releases of peptides (FSP), calcium, and phosphate from fish scales occurred simultaneously, and the chelation was also effectively performed. After a 6-h hydrolysis, the yield of FSP was 46.18%, and the dissolution rate of calcium was 49.53%. Under the optimal conditions (pH 7, chelation time of 25 min, and chelation temperature of 48 °C), a high chelation rate of 86.16% was obtained, with a calcium content of 81.8 mg/g. The results of UV absorption, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) confirmed the successful chelation between FSP and calcium derived from fish scales. The –NH2, –COO–, N–H, C=O, C–H, and –OH groups in FSP participated in the formation of FSP-Ca. [ABSTRACT FROM AUTHOR]

The utilization of biowaste fillers in the development of high-density polyurethane (PU) foams has gained significant attention due to environmental and economic benefits. This study investigates the mechanical properties of PU foams reinforced with biowaste fillers extracted from fish scales (FS) and fish scale-derived collagen (FSC). The fish scales and collagen were characterized for their composition and integrated into PU foams at various loadings. Mechanical properties such as tensile strength, hardness, and density were evaluated. ANOVA was used to analyze the mean values. Bonferroni tests were used to identify differences between the filler materials (α = 0.05). The tensile strength increases with an increase in filler content for both FS (59.48 Kpa) and FSC (65.43 Kpa). No differences were observed between FS and FSC in tensile strength. Significant differences were observed between the FS and FSC in both hardness and density (p < 0.001). The results demonstrated that both fillers enhanced the mechanical properties of PU foams, with collagen-reinforced foams showing superior performance. This suggests that collagen and fish scales can be effective biowaste fillers for developing environmentally friendly PU foams with enhanced mechanical properties.

Copyright of Ecoscience (Ecoscience) is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carbon dots (CDs) are a kind of novel carbon nanomaterial that has unique properties, which make them useful for various applications, and now newer types of CDs are being found. Herein, a series of easy, cost-effective, environmentally friendly and highly biocompatible one-step syntheses of fluorescent CDs were fabricated by reacting easily available aquatic waste used as the carbon source, using hydrothermal reaction. The rapid development of nanomaterials has provided unprecedented opportunities for various applications, and CDs have been widely used in pharmaceutical analysis, environmental monitoring, clinical diagnosis, medical imaging technologies and cancer treatment. Good biocompatibility is a prerequisite for the application of nanomaterials in biology, chemistry, medicine and other fields. This paper presents a systematic study of the biocompatibility and biosafety issues of the three as-synthesized CDs, including primary investigations of their cytotoxicity, cell morphology, plant imaging, apoptosis analysis and effects on embryos in zebrafish embryos. The aim of this research is to make a profound study on the biocompatibility of carbon dots and explore the application of CDs in the field of biological imaging. A series of easy, cost-effective, and environmentally friendly fluorescent carbon dots was synthesized with aquatic waste, and the biocompatibility of the three carbon dots was systematically studied. [ABSTRACT FROM AUTHOR]

The current work describes the removal efficiency of a hazardous azo dye such as Eriochrome Black T from aqueous solution using Sardina fish scales as an inexpensive biosorbent which the characterisation results indicate the presence of hydroxyapatite and collagen fibres. Various parameters that can influence the uptake, like contact time, pH, biosorbent dose were investigated, and the optimal experimental removal efficiency was found at acidic pH. The adsorption behaviour of EBT dye on both collagen and hydroxyapatite (HDA) was highlighted using Metropolis Monte Carlo (MC), radial distribution function (RDF), the density functional theory (DFT), and the electrostatic potential surface (ESP) calculations. The findings result in evidence that the EBT dye presents more capabilityto be adsorbed on the collagen than on the HDA surface mainly in an acidic medium. A good agreement between experimental and theoretical conclusions is obtained. The results illustrated that the experimental data were well followed by the pseudo-second-order kinetic and Freundlich isotherm models. Thermodynamic parameters were determined and show that the biosorption of dye was endothermic. [ABSTRACT FROM AUTHOR]

This study aims to determine the papain soluble collagen from the milkfish scale based on the yield and antioxidant activity due to treatment of extraction time and papain concentration. Papain soluble collagen (PSC) was isolated from the scales of milkfish (Chanos chanos) caught in Sidoarjo, Indonesia, with a total production of 828,372.62 tons in 2018. Independent variables of extraction time were (X1, hour) and papain concentration (X2, U/mg). Dependent variables were yield (Y1, %) and antioxidant activity (Y2, mg/L).This research used Response Surface Methodology. The result showed that the extraction time and papain concentration from 24 hours to 82 hours with papain concentration 3000 U/mg to 7000 U/mg resulted in yield 2.25% to 6.4% and antioxidant activity of 199 mg/L to 418 mg/L. The optimal condition of extraction PSC was 56.45 hours with papain concentration 5950 U/mg resulting in a yield of 6, 0%±0,012 and antioxidant activity of 258±0, 98 mg/L.

Egg shells and fish scales are two abundantly available by-products from food industries which can be used as filler materials to reinforce polymer composites. The bulk of discarded chicken eggshells and fish scales are disposed of in landfills, which cause environmental issues. The present research work focuses on the water absorption, mechanical and tribological properties of epoxy composites reinforced with chicken eggshells and catla fish scale particles. Hybrid composites incorporating both fillers were also made and evaluated. Results from the water absorption tests showed that the addition of fillers decreased the water absorption of the composites than neat epoxy. Tensile and impact tests revealed that the inclusion of fillers reduced the tensile and impact strength of the composites compared to neat epoxy, but improved the tensile modulus. The hybrid composite (EFREC) showed improvement in both flexural strength and modulus in comparison to neat epoxy. Also, the results from the wear tests revealed that the addition of fillers improved the wear resistance of the composites. Among all the mechanical and wear tested composite specimens, the hybrid composite (EFREC) showed the best performance. This was also validated from the SEM images of the fracture and wear surfaces of the composites. [ABSTRACT FROM AUTHOR]

Aim of this research paper was to investigate the potential of fish scales as an adsorbent for crystal violet dye exclusion from wastewater and to optimize various adsorption parameters for maximum adsorption of dye. Parameters studied were solution pH, adsorbent dose, contact time, dye concentration, and temperature. Results showed maximum percentage degradation, i.e., 90% under optimized conditions such as pH 12 solution, 0.4 g adsorbent dose, with 40 min of exposure time and 40 ppm of dye concentration at 10 °C solution temperature. Adsorbent was characterized using FTIR, and SEM techniques to explore the functionality and to study morphology of adsorbent, respectively. Results confirmed that carboxyl, amino, phosphate, and sulfonate groups and heterogeneous adsorbent surface was accountable for crystal violet dye adsorption on fish scales. pH pzc of the fish scale was 8. Adsorption isotherms such as Langmuir, Freundlich, and D-R isotherm models were also investigated. Contact time data was applied to various kinetic models, i.e., pseudo-first order, and pseudo-second order kinetic models. Thermodynamic study was also investigated. Results confirmed that experimental data fitted well to Freundlich isotherm model ( R 2 = 0.9983) and pseudo second order kinetic model ( R 2 = 0.9970) as ARE error analysis values of these models were 1.191692 E + 06 and −160.66, respectively (lower than that of other models. Computed ΔG and ΔH values confirmed adsorption process to be spontaneous and of endothermic kind. Applicability of established procedure with tap water was 78% and regeneration percentage was 72% which showed the effectiveness of fish scales powder for removal of crystal violet dye from wastewater. [ABSTRACT FROM AUTHOR]

Objectives: Dentine hypersensitivity (DH) is a common concern in dentistry that has the potential to restrict daily activities and harm a person's quality of life. In this study, the remineralization characteristics of nano-hydroxyapatite (nHAp) extracted from waste eggshells and fish scales were comparatively assessed. Materials and methods: The extraction methods used to obtain nHAp from both fish scales and eggshells are also described. The effect of the extraction process and bio-waste source on the physicochemical characteristics of the nHAp such as Ca/P ratio, functional groups, crystallinity and phase change, and surface morphology are presented in the study. The remineralization properties were evaluated using dentine models (n = 15). A field scanning electron microscope was used to evaluate the effectiveness of the dentine tubules occlusion. The percentage occluded area for all the specimens was evaluated statistically using a one-way analysis of variance (α = 0.05). Results: The results showed that there were variations in the physicochemical characteristics of the nHAp extracted, including the crystallinity, particle size, and surface morphology, and buffering effects against citric acids. The EnHAp extracted from eggshells had higher crystallinity, superior buffering effects, and smaller particle size compared to the nHAp extracted from fish scales, making it a more favourable material for remineralization of teeth. The statistical evidence showed that there were statistically significant differences in the dentine occluding properties measured in the nHAp (p < 0.001). The highest mean % occluded area was measured with the EnHAp group. Conclusions: The findings of this study provide insights into the use of bio-waste materials for the development of sustainable and effective products for oral health care. [ABSTRACT FROM AUTHOR]

Gelatin (G) is a thermoreversible polymer produced by hydrolysis of a structural protein called collagen. Fish scales (mixed freshwater species) were subjected to hydrochloric acid (HCl), sodium hydroxide (NaOH) and both HCl and NaOH pretreatment individually, and gelatin extraction with distilled water was labeled as GA, GB and GC, respectively. The percentage yield of gelatin GB (9.6 ± 0.5%) was higher than GA (7 ± 0.2%) and GC (9 ± 1.4%). Amino acids and imino acids (proline and hydroxyproline) composition confirmed the characteristic nature of collagen. The gel strength of gelatin was affected by the pH of the extraction medium rather than the presence of imino acid composition. Extracted gelatin GA, GB and GC showed ʎmax at 230 nm indicating the peptide bond of gelatin and the presence of five amide bands I, II, III, A and B revealing the intrinsic nature of functional groups C=O, C–N, C–N, N–H and –NH3 stretching vibrations of collagen, respectively. Two diffraction peaks of 2ɵ, one sharp peak around 10° and one broad peak around 20° represent the partially crystalline nature of fish gelatin. The presence of β, α1 and α2 chain at around 200 KDa, 110 KDa and 100 KDa, respectively, confirmed the triple helix nature of the gelatin. Glass transition temperature (Tg) of gelatin GA, GB and GC at 76.3 °C, 72.9 °C and 71.4 °C, respectively, and melting temperature (Tm) of GA, GB and GC at 406 °C, 295.2 °C and 291.7 °C, respectively, were evident through thermal study. The effect of acidic and alkaline pretreatment of fish scale had displayed fibrillar pattern, evenly spaced porous nature and network-like structure of gelatin which was thermally stable up to ~ 300 °C. Hence, waste fish scales have proved to be a cost-effective and environmentally friendly alternative raw material for gelatin production paving the way for safe alternatives for biomedical application. [ABSTRACT FROM AUTHOR]

Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials. Here bioinspired magnesium composites with fish-scale-like orthogonal plywood and double-Bouligand architectures were developed by pressureless infiltration of a magnesium melt into the woven contextures of continuous titanium fibers. The composites exhibit enhanced strength and work-hardening ability compared to those estimated from a simple mixture of their constituents at ambient to elevated temperatures. In particular, the double-Bouligand architecture can effectively deflect cracking paths, alleviate strain localization, and adaptively reorient titanium fibers within the magnesium matrix during the deformation of the composite, representing a successful implementation of the property-optimizing mechanisms in fish scales. The strength of the composites, specifically the effect of their bioinspired architectures, was interpreted based on the adaptation of classical laminate theory. This study may offer a feasible approach for developing new bioinspired metal-matrix composites with improved performance and provide theoretical guidance for their architectural designs.

Copyright of Journal of Plant Production is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fish scales are usually discarded directly after the fish are slaughtered, which causes serious environmental pollution. The production of activated carbon with fish scales is one of the most effective techniques for a cheap, environmentally friendly, and high-removal adsorbent material. Activated carbon was produced from waste fish scales (Cyprinus carpio) with surface modification with H3PO4. The novel adsorbent material was used to investigate the green removal of the toxic dye methylene blue. BET, SEM, and FT-IR analyses were used to characterize activated carbons. The activated carbon surface area achieved was 758.574 m2 g-1. The effect of pH and solution concentration, which are important parameters of the adsorption, was investigated. It was found that the kinetic results of the adsorption process best fit the pseudo-second order (PSO) kinetic model and the equilibrium results best fit the Langmuir isotherm. According to the Langmuir isotherm data, the maximum adsorption capacity (qmax) was 119.04 mg g-1. The surface morphology and high adsorption capacity of activated carbon produced from fish scales are promising precursors for a novel adsorbent material. [ABSTRACT FROM AUTHOR]

In the present study, an inexpensive bioadsorbent was developed using fish scales treated by a novel alkaline heat treatment process to extract hydroxyapatite. The synthesized glutaraldehyde crosslinked Chitosan@Hydroxyapatite biocomposite was characterized by FT-IR spectroscopy, X-ray diffraction, and SEM-EDS analyses and applied as tunable biosorbent for Orange G dye. To evaluate the efficiency of adsorption, the influence of the initial pH, contact time, and initial dye concentration on the process was investigated. The highest adsorption capacity was 217.466 mg g−1, and the adsorption experimental results for OG dye molecules matched well with the pseudo-second-order and Langmuir isotherm models. Concerning the thermodynamic parameters, the ∆G and ∆H values confirm the spontaneous and exothermic character of the adsorption process. Additionally, FT-IR spectroscopy revealed that the OG adsorption occurs through hydrogen bonding and electrostatic interaction between the free hydroxyl and amino groups present on the biocomposite surface and the sulfonate groups in the OG molecules. Response surface methodology based on Box–Behnken design (RSM-BBD) was applied to optimize the effects of the main input factors to remove OG dye. An optimum OG dye removal efficiency of 92% was obtained at 12.5 mg adsorbent dose, 50 mg L−1 dye concentration, and 120 min contact time. CT-GA@HAp hybrid was successfully regenerated up to the fifth cycle, indicating that it can be used as a promising, feasible and environmentally friendly biosorbent composite. [ABSTRACT FROM AUTHOR]

Tendon-bone healing is essential for an effective rotator cuff tendon repair surgery, however, this remains a significant challenge due to the lack of biomaterials with high strength and bioactivity. Inspired by the high-performance exoskeleton of natural organisms, we set out to apply natural fish scale (FS) modified by calcium silicate nanoparticles (CS NPs) as a new biomaterial (CS-FS) to overcome the challenge. Benefit from its “Bouligand” microstructure, such FS-based scaffold maintained excellent tensile strength (125.05 MPa) and toughness (14.16 MJ/m3), which are 1.93 and 2.72 times that of natural tendon respectively, allowing it to well meet the requirements for rotator cuff tendon repair. Additionally, CS-FS showed diverse bioactivities by stimulating the differentiation and phenotypic maintenance of multiple types of cells participated into the composition of tendon-bone junction, (e.g. bone marrow mesenchymal stem cells (BMSCs), chondrocyte, and tendon stem/progenitor cells (TSPCs)). In both rat and rabbit rotator cuff tear (RCT) models, CS-FS played a key role in the tendon-bone interface regeneration and biomechanical function, which may be achieved by activating BMP-2/Smad/Runx2 pathway in BMSCs. Therefore, natural fish scale -based biomaterials are the promising candidate for clinical tendon repair due to their outstanding strength and bioactivity.

In this paper, the microstructure characteristics and mechanical properties (including nano‐indentation, tensile, and penetration behaviors) of the scales from pinecone fish (Monocentris japonica) were investigated. The M. japonica scales display a unique hierarchical structure and consist of three layers: an outer bone layer with high mineralization, an intermediate bone layer with obvious pore structures, and an inner collagen layer composed of multiple plies of collagen fibers. The hardness and indentation modulus of the three structural layers exhibit gradient changes, and decrease gradually from the outer layer to the inner layer. Tensile tests show that the tensile response and failure modes of the scales are different under dry and hydrated conditions. The dry scales have higher tensile strength (46.35 MPa) and Young's modulus (0.74 GPa), while the hydrated scales exhibit higher ultimate strain (20.18%) and toughness (4.57 MPa). Penetration tests indicate that the scales have a significantly high resistance to penetration, and increase the penetration force by more than six times compared with the descaled skin. Furthermore, the structure–property relationship of the M. japonica scales was discussed. It is found that the hard outer layer and the porous intermediate layer help to disperse the stress, and the soft inner layer containing collagen fiber plies helps to deflect the crack propagation, which are responsible for the excellent mechanical properties of the scales. The outcome of this study can provide a valuable biomimetic design inspiration for lightweight and high‐strength composite materials in engineering fields. Research Highlights: Microstructure characteristics and mechanical properties of the Monocentris japonica scales were investigated.The M. japonica scales can be divided into three layers rather than two layers.The M. japonica scales exhibited high tensile strength and penetration resistance. [ABSTRACT FROM AUTHOR]

Synthetic plastics are becoming hazardous wastes, posing a threat to environmental sustainable health; hence, they must be replaced with alternatives. This study aimed to prepare corn starch-based bioplastics using fish scale through film casting technique as an alternative to synthetic plastics. In this work, four types of bioplastic films (CSF, CSFSF1, CSFSF2, FSF) containing different percentages of fish-scale powder and corn starch were prepared. Physical and chemical properties such as texture, color, solubility in hot water, tensile strength, functional groups, and morphology of all the four types of the prepared bioplastics were analyzed. The mixture of fish-scale powder and corn starch powder in the ratio of 1:3 (CSFSF1) yielded the best results. Its average thickness is 0.0420 ± 0.001 mm, water absorption range is 55–60%, tensile strength is 6.06 ± 0.05 MPa, and thermal stability is 278.741 °C. In the biodegradability test, degradation was noticed after 7 days of treatment with organic waste. The degradation was confirmed by surface changes in the morphology and the development of Aspergillus sp. Corn starch film (CSF) exhibited the highest degradation (60%), while the fish-scales film (FSF) underwent the least degradation (28%). The produced bioplastics were prepared from eco-friendly, inexpensive, and natural materials. Thus, the present research has provided a viable alternative to synthetic plastics. [ABSTRACT FROM AUTHOR]

Natural fish scales demonstrate outstanding mechanical efficiency owing to their elaborate architectures and thereby may serve as ideal prototypes for the architectural design of man-made materials. Here bioinspired magnesium composites with fish-scale-like orthogonal plywood and double-Bouligand architectures were developed by pressureless infiltration of a magnesium melt into the woven contextures of continuous titanium fibers. The composites exhibit enhanced strength and work-hardening ability compared to those estimated from a simple mixture of their constituents at ambient to elevated temperatures. In particular, the double-Bouligand architecture can effectively deflect cracking paths, alleviate strain localization, and adaptively reorient titanium fibers within the magnesium matrix during the deformation of the composite, representing a successful implementation of the property-optimizing mechanisms in fish scales. The strength of the composites, specifically the effect of their bioinspired architectures, was interpreted based on the adaptation of classical laminate theory. This study may offer a feasible approach for developing new bioinspired metal-matrix composites with improved performance and provide theoretical guidance for their architectural designs. [Display omitted] [ABSTRACT FROM AUTHOR]

Bouligand structures are widely observed in natural materials; elasmoid fish scales and the exoskeleton of arthropods, such as lobsters, crabs, mantis shrimp and insects, are prime examples. In fish scales, such as those of the Arapaima gigas, the tough inner core beneath the harder surface of the scale displays a Bouligand structure comprising a layered arrangement of collagen fibrils with an orthogonal or twisted staircase (or plywood) architecture. A much rarer variation of this structure, the double-twisted Bouligand structure, has been discovered in the primitive elasmoid scales of the coelacanth fish; this architecture is quite distinct from “modern” elasmoid fish scales yet provides extraordinary resistance to deformation and fracture. Here we examine the toughening mechanisms created by the double-twisted Bouligand structure in comparison to those generated by the more common single Bouligand structures. Specifically, we have developed an orientation-dependent, hyperelastic, phase-field fracture mechanics method to computationally examine the relative fracture toughness of elasmoid fish scales comprising single vs. double-twisted Bouligand structures of fibrils. The model demonstrates the critical role played by the extra inter-bundle fibrils found in coelacanth fish scales in enhancing the toughness of Bouligand-type structures. Synthesis and fracture tests of 3-D printed Bouligand-type materials are presented to support the modeling and complement our understanding of the fracture mechanisms in Bouligand-type structures.

Bouligand structures are widely observed in natural materials; elasmoid fish scales and the exoskeleton of arthropods, such as lobsters, crabs, mantis shrimp and insects, are prime examples. In fish scales, such as those of the Arapaima gigas, the tough inner core beneath the harder surface of the scale displays a Bouligand structure comprising a layered arrangement of collagen fibrils with an orthogonal or twisted staircase (or plywood) architecture. A much rarer variation of this structure, the double-twisted Bouligand structure, has been discovered in the primitive elasmoid scales of the coelacanth fish; this architecture is quite distinct from “modern” elasmoid fish scales yet provides extraordinary resistance to deformation and fracture. Here we examine the toughening mechanisms created by the double-twisted Bouligand structure in comparison to those generated by the more common single Bouligand structures. Specifically, we have developed an orientation-dependent, hyperelastic, phase-field fracture mechanics method to computationally examine the relative fracture toughness of elasmoid fish scales comprising single vs. double-twisted Bouligand structures of fibrils. The model demonstrates the critical role played by the extra inter-bundle fibrils found in coelacanth fish scales in enhancing the toughness of Bouligand-type structures. Synthesis and fracture tests of 3-D printed Bouligand-type materials are presented to support the modeling and complement our understanding of the fracture mechanisms in Bouligand-type structures.

The present study was conducted to prepare the fish scales' hydroxyapatite/collagen beads (FsHA/FsCol) and characterize their biological, physical, and chemical properties. A new method was used to prepare FsHA/FsCol composite beads by infiltrating the beads of FsHA in the solution of FsCol as a green method. X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) analysis, Fourier-transform infrared (FTIR) spectroscopy analysis and energy dispersive X-ray analysis (EDX), used to evaluate the physical-chemical properties of the synthesized samples. Meanwhile, the cytotoxic and attachment studies of the FsHA/FsCol beads were used to investigate the biological features against the MG-63 human cell line. The results specified the efficiency of the new method, functional groups of FsCol were indicated to be present inside the beads of FsHA according to the XRD analysis which shows the functional peaks of FsCol. The SEM image were conformed successfully use starch as a porous agent to increasing the porous of the FsHA beads after adding 20 wt% of it. Alamar Blue assay has been used to evaluate the cytotoxicity of FsHA/FsCol beads the results were shown 87% average cell viability of the MG-63 human cell line on the beads and attached very well to the surface of the composites, indicating no toxicity being exerted by all the composites at high concentrations.

Macro‐ and microscopic characteristics of flank scales for 12 species were investigated from the Persian Gulf Coral Reefs. In Lutjanus argentimaculatus and L. russellii (family Lutjanidae), the scales of different flank regions were not different, while four characters showed variation in the scale of L. lutjanus i.e., scale shape (pentagonal, hexagonal and square), anterior margin (waved, scalloped and smooth), focus shape (circular and oblong) and focus position (postero‐central and central), displayed variation. Scale type (ctenoid) and posterior margin (transforming ctenii) did not show variation and could be considered to be specific in this family. In Epinephelus chlorostigma (family Serranidae), the scales of flank regions did not display variation, while in E. areolatus, E. diacanthus and E. radiates, the scales showed considerable variation. The most variable characters were scale shape, posterior margin and focus shape. Therefore, in fish systematics studies on the base of scale, it is particularly important to compare scales from the same flank regions. Also, some criteria such as size‐dependent alternation, ontogenetic changes and variation between flank regions, should be considered. This study supports the potential of scale morphology to help for the understanding of fish diversity in the coral reef ecosystem. [ABSTRACT FROM AUTHOR]

Studies on genetic diversity require biological material containing a reliable source of DNA that can be extracted and analyzed. Recently, non-invasive sampling has become a preferred sampling method of biological material. The suitability of a less invasive approach that involves obtaining samples by swabbing the fish skin (including live, non-anesthetized fish) should be considered. In this study, we compared the efficiency of DNA extraction, amplification, and sequencing of mtDNA fragments of two fish species Perca fluviatilis and Rutilus rutilus based on DNA collected from the scales and mucus using the modified Aljanabi and Martinez method. The results revealed a higher quality of DNA extracted from the mucus; however, the mean DNA concentration obtained from the scales of both fish species was higher. We verified the method suitable for amplification and sequencing of mtDNA fragments of both fish species using newly designed markers (D-loop, ATP6) and examined the potential risk of intraspecific cross-contamination. The DNA sequence alignment analysis revealed identical sequences attributed to the same individual when DNA, extracted from two different sources (scales and mucus), was used. We demonstrated that the quantity and quality of DNA extracted from the scales and mucus using the proposed method were high enough to carry out genetic diversity studies based on sampling of live fish with the possibility to release it after collecting samples. [ABSTRACT FROM AUTHOR]

Water pollution is one of the most serious environmental issues facing the world, including India. The present study mainly focuses on removal of major pollutant from agriculture wastewater that is responsible for eutrophication in water, that is, phosphates. Fish scales and Hami‐melon peels were used as adsorbents in this investigation. Numerous studies are carried out for how effective adsorbents are at removing the pollutant phosphate. Equilibrium studies, thermodynamic studies, kinetic studies, and isotherm studies are all variations of these types of investigations. According to investigations, both the adsorbents of 0.2% concentration at 165 rpm with pH 6 and a constant temperature of 30°C can successfully remove 95%–97% of phosphate. The initial concentration of the pollutant was also varied from 30 to 70 ppm and the pH is varied from 3 to 9 which showed the maximum adsorption occurred in the range of 5–7. Additionally, contact time varied at an intervals of 10 min to determine the optimum contact time and was found to be 140 min. The uptake capacities 24.15 mg/g for fish scales as adsorbent whereas 23.94 mg/g for Hami melon peels as adsorbent. The isotherm studies showed that Langmuir isotherm fits well where second order kinetics is suited based on kinetic studies. The thermodynamic studies showed that fish scales and Hami melon peels are suitable to remove phosphates since the adsorption occurred is spontaneous and the reaction is endothermic in nature. [ABSTRACT FROM AUTHOR]

In this paper, the preparation of polypeptides and the synthesis of polypeptide metal chelates from American red fish（Sciaenops ocellatus ）scales were studied and optimized. Polypeptides were prepared from the scales of American red fish. The molecular weight of the peptides was analyzed by gel chromatography. Polypeptide metal chelates were synthesized by water system method and the metal chelating rate was determined by EDTA complexometric titration method. L9(34) orthogonal test was used to optimize the processing conditions of polypeptide metal chelates. The binding of polypeptide to metal was verified by detecting polypeptide and metal chelate by infrared spectroscopy. The molecular weight of polypeptide was about 1~6 kDa by gel chromatography analysis. The preparation conditions of polypeptide zinc chelate were obtained by orthogonal experiment, that is, the mass ratio of zinc chelate was 2:1, pH5.5, temperature 55℃, time 60 min. The optimal chelating conditions were mass ratio 2:1, pH6.0, temperature 35℃ and time 55 min. Under the optimized condition, the chelate ratio of zinc and copper were 78.21% and 91.24% respectively. The infrared absorption spectra showed that Zn2+, Cu2+ and -NH2 were successfully combined. The results showed that the chelation rate was significantly improved under the condition of this process, and it was rich in metal ions, low cost and promising market prospect, which would be conducive to the high-value application of marine fishery processing by-products and promote the technological upgrading of fishery processing industry.

Here, experiments and analysis revealing the unique defense mechanisms of the coelacanth, a lobe-finned fish termed a “living fossil”, are reported, as it was considered to be extinct until 1938, but extant for 400 million years. This defense is provided by primitive elasmoid scales having a rare double-twisted Bouligand structure of lamellae which provides extraordinary resistance to deformation without failure. Distinct from other elasmoid scales, the collagen fibrils in the coelacanth fish scales form bundles which are embedded in a matrix comprising fibers arranged perpendicular to the layered (double-twisted Bouligand) structure that provide added rigidity and resistance to deformation. Using in situ synchrotron small-angle X-ray scattering during uniaxial tensile testing, the deformation mechanisms of the collagen are identified in terms of fibril stretching, reorientation, sliding, bending, and delamination. The unique structure of the coelacanth scales, distinct from modern elasmoid scales such as the carp, provides a variety of mechanisms to arrest cracking, making it an outstanding damage-tolerant material to resist predator attacks.

In the present study, the biosorptive potential of Cyprinus carpio scales for the removal of Fe, Mn, and Zn ions from real acidic mine drainage (AMD) generated at the Rosia Montana gold mine (Romania) was explored for the first time. The collected AMD solution is very acidic, and the concentrations of Fe, Mn, and Zn ions exceed more than 34 to 56 times the disposal standards imposed by legislation. Batch adsorption experiments were carried out to study the effect of the sorbent dosage, sorbent particle size, pH, and contact time on the adsorption performance of the fish scales. Before and after the adsorption process, the biosorbent was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (SEM-EDX). In the investigated experimental conditions, about 100%, 87.1%, and 100% of Fe, Mn, and Zn ions were removed from the AMD after 240 min of contact with the finest-grained Cyprinus carpio scale samples using a solid:liquid ratio of 20:1 (g:L). The adsorption data were analyzed using the pseudo-first order, pseudo-second order, intraparticle diffusion rate, and Elovich equations. The adsorption process was found to follow the pseudo-second-order kinetic model. The maximum adsorption capacities of the fish scales were about 2.46 mg/g for Mn and 0.85 mg/g for Zn ions, respectively. Aside from their significant efficiency in the removal of metals from AMD, Cyprinus carpio scales also have the potential to neutralize the acidic wastewater. Thus, the removal process of metal ions from AMD is ruled by a complex mechanism, including adsorption and iron precipitation. The recycled scales are still able to remove the metal ions from AMD with a better performance during the first regeneration cycle. Based on the obtained results, it might be assessed that the low-cost biowaste of Cyprinus carpio scales have great potential and could be effectively used for the remediation of real acidic mine drainage from a sustainable perspective. [ABSTRACT FROM AUTHOR]

Nanotechnology deals with the new facets of materials described as nanomaterials which have interesting attributes like large surface area to volume ratio compared to its native form. The goal of this study was to prepare chitosan nanomaterial and Amphotericin B conjugated chitosan nanomaterial from the chitosan polymer extracted from the fish scales. Generally, the rise of antibiotic resistant microorganisms demanded large scale exploitation of these polymeric nanomaterials. The limitations of standard Amphotericin B in terms of its instability issues, poor water solubility, and toxicities are solved by conjugating the drug with pure chitosan nanomaterial. The physicochemical characterization of the fabricated nanomaterials was analyzed using SEM-EDAX, FTIR, XRD, UV–Visible spectroscopy. The mean particle size of CS NM and AmB-conjugated CS NM was found to be 2.5 µm and 0.19 µm. Both nanomaterials are spherical shaped and highly stable. In vitro antifungal susceptibility testing using Candida parapsilopsis showed a dose dependent fungicidal activity by both nanomaterials. The antifungal activity was accessed. Additionally, the antibiofilm activity of the prepared nanomaterials was also examined. From the current study Amphotericin B conjugated chitosan nanomaterial manifested a superior antifungal activity compared to the parent nanomaterials. [ABSTRACT FROM AUTHOR]

In search of alternative and sustainable sources of collagenous materials for biomedical applications, the scales of five Mediterranean fish species—fished in high tonnage in the Mediterranean region since they represent popular choices for the local diet—as well as those of the Atlantic salmon for comparison purposes, were comparatively studied for their acid- and pepsin-soluble collagen content. Fish scales that currently represent a discarded biomass of no value could be efficiently exploited for the production of a high added-value biomaterial. The isolated collagenous materials, which showed the typical electrophoretic patterns of type I collagen, were morphologically and physicochemically characterized. Using scanning electron microscopy the fibrous morphology of the isolated collagens was confirmed, while the hydroxyproline content, in conjunction with infrared spectroscopy and X-ray diffraction studies verified the characteristic for collagen amino acid profile and its secondary structure. The acid- and pepsin-soluble collagens isolated from the fish scales were blended with the bioactive sulfated marine polysaccharide ulvan and polyethylene oxide and electrospun to afford nanofibrous scaffolds that could find applications in the biomedical sector. [ABSTRACT FROM AUTHOR]

Nano-hydroxyapatite (nHAp) as a bio-filler used in PLA composites was prepared from fish by acid deproteinization (1DP) and a combination of acid-alkali deproteinization (2DP) followed by alkali heat treatment. Moreover, the PLA/nHAp composite films were developed using solution casting method. The mechanical and thermal properties of the PLA composite films with nHAp from different steps deproteinization and contents were compared. The physical properties analysis confirmed that the nHAp can be prepared from fish scales using both steps deproteinization. 1DP-nHAp showed higher surface area and lower crystallinity than 2DP-nHAp. This gave advantage of 1DP-nHAp for use as filler. PLA composite with 1DP-nHAp gave tensile strength of 66.41 ± 3.63 MPa and Young's modulus of 2.65 ± 0.05 GPa which were higher than 2DP-nHAp at the same content. The addition of 5 phr 1DP-nHAp into PLA significantly improved the tensile strength and Young's modulus. PLA composite solution with 1DP-nHAp at 5 phr showed electrospinnability by giving continuous fibers without beads. [ABSTRACT FROM AUTHOR]

The aim of the study was to investigate the accumulation of cadmium in the scales of Prussian carp (Carassius gibelio B.) as an indicator tissue of water contamination by cadmium. The study was carried out on 70 mature Prussian carp, which were placed in three 300L tanks. The fish were exposed to cadmium dissolved in water at a concentration of 0.0, 0.4 or 4.0 mg L-1 for a period of 84 days. After 42 and 84 days of exposure, 10 fish were randomly sampled from each tank. The fish were decapitated and all their scales were collected. The scales were rinsed and each was then carefully sectioned into an inner part and an outer part, removing the outermost growth ring, which most likely included scale increment from the exposure period. Cadmium concentration in the samples was then measured using the atomic absorption method. The analysis of the results showed that the concentration of cadmium in the scales increased with the duration of exposure and was significantly higher in the outer growth rings. The accumulation of cadmium in this part of the scales was correlated with the dose of cadmium and the duration of exposure. The results obtained confirmed the hypothesis that the concentration of cadmium in the outermost growth rings of fish scales reflects the most recent status of environmental contamination by this metal. Scales, which - unlike other tissues such as the liver and muscle - can be sampled non-lethally, seem to be an excellent bioindicator of environmental contamination by heavy metals. [ABSTRACT FROM AUTHOR]

The waste generated by the global fishing industry, such as fish scales, is mostly considered useless and discarded in a disorderly and/or unplanned way in inappropriate places, posing serious risks to both the environment and human health. This study proposes the use of fish scales in combustion processes as an alternative for such residues and to avoid their exposure in urban areas. Combustion experiments were conducted in a drop tube furnace (DTF), and the factors temperature, residence time, and sample particle size were investigated. The main atmospheric pollutants (CO, NO, CO2, and SO2) and the residues generated from the combustion processes were characterized by FTIR, EDS and ICP-OES analyses, and SEM images. The samples showed better performance at 1100 °C and 500 -ms residence time, when the burnout reached 96%, and particle size greater than 300-μm and 300-ms residence time led to the worst combustion performance (24.45% burnout), with the highest CO and NO peaks, indicating incomplete combustion of the fish scales. The analysis of the residues revealed total decomposition of the organic matter at temperatures above 700 °C and formation of hydroxyapatite. According to the DTF results, the use of fish scales in firing processes is a viable treatment of the residues, generating energy and avoiding environmental problems caused by inadequate disposal. [ABSTRACT FROM AUTHOR]

The mineralization process of the osseous layer, which is highly calcified in vivo, was successfully imitated by the immersion process of the decalcified fish scales in simplified simulated body fluid (SSBF). An alkali treatment was used to modify the native collagen in the decalcified Tilapia fish scale. After the alkali treatment, the mineralization was facilitated in SSBF. The XRD patterns and SEM-EDS observation results demonstrated that the externally-mineralized layers by the immersion process were highly similar to the osseous layer containing lower-crystalline hydroxyapatite, suggesting that the simple biomimetic precipitation process was developed. [ABSTRACT FROM AUTHOR]

Only 2.5% of the world's water is fresh, despite the fact that water covers approximately 70% of the planet. This water is used for several recreational purposes and gets polluted by wastewater disposal directly into freshwater bodies. Effluents dispersed into water bodies could be from various sources like industries, households, and agricultural activities. These effluents comprise heavy metals and chemical wastes directly released into water bodies without treatment and could include major contaminants like nitrates, nitrites, ammonia and phosphates. The present study mainly focuses on removal of four significant pollutants from agriculture wastes, i.e., nitrates, nitrites, ammonia, and phosphates. These pollutants are removed using adsorbents via a process known as adsorption. Adsorbents used in the study are fish scales and neem leaves. Several studies have been carried out to measure the efficiency of adsorbents in the removal of contaminants. These studies include equilibrium studies, kinetic studies and isotherm studies. Based on a complete analysis and results obtained, 95% to 99% of contaminants can be removed effectively with an adsorbent dosage of 0.4g (0.2 g of fish scale and 0.2 g of neem leaves powder), optimum pH of 6 and at 303K constant temperature. The dosage variance stems from changing the dosages of two adsorbents in three ways, i.e., by taking both adsorbents in equal dosages, and increasing the dosage of one adsorbent compared to the other and vice versa. The contact time varied from 0 to 140min and the Initial concentration of pollutants has also been varied from 30 to 70 mg/L. In addition to the above variations, thermodynamic studies were also done, and based on the negative values of ΔG and positive value of ΔH and ΔS, it is evident that the reaction of novel adsorbent (combination of fish scales and neem leaves) is spontaneous and endothermic. HIGHLIGHTS Agricultural wastewater pollutants causing eutrophication is one of the reasons for polluting the river bodies.; These pollutants, i.e. nitrates, nitrites, ammonia and phosphates, were treated by integrating two waste materials, fish scales and neem leaves, as single adsorbent.; About 95% to 99% of contaminants could be removed from the considered pollutant concentration.; Kinetic and isotherm studies were also included in the study.;

Abstract The high plasma glucose induced in glucose metabolism disorders leads to the non‐enzymatic glucose‐dependent modification (glycation) of type 1 collagen, which is an essential component of bone tissue. The glycation of proteins induces the formation of advanced glycation end‐products, such as carboxymethyl arginine, which is preferentially generated in glycated collagen. However, the effect of advanced glycation end‐product formation on the characteristics of type 1 collagen remains unclear due to the lack of suitable in vitro experimental systems analyzing type 1 collagen. Here, we show that the glycation of type 1 collagen can be analyzed in vitro using a goldfish‐scale bone model. Our study using these scales provides evidence that the advanced glycation end‐product formation in type 1 collagen induced by glyoxal, the carboxymethyl arginine inducer, facilitates the crosslinking of type 1 collagen, decreasing both its strength and flexibility.

This work investigates the possibility of using scales of sea bass Dicentrarchus labrax as a low-cost material for the adsorptive removal of methylene blue (MB) cationic dye in aqueous solutions. The physical–chemical characterizations of fish scales in natura (FS-in natura) revealed through thermogravimetry that they are composed of inorganic (hydroxyapatite) and organic (collagen) phases in relatively similar amounts. Spectroscopy analyses show that the interactions of MB with FS-in natura occur mainly in the organic phase layer of the adsorbent. The effects of initial MB concentration (5.0 × 10–4 and 5.0 × 10–3 mol L−1) and temperature (25–55 °C) on the adsorption efficiency of FS-in natura were evaluated. FS-in natura at MB concentration (5.0 × 10–3 and 5.0 × 10–4 mol L−1) exhibited the maximum adsorption capacities of 2.2 × 10–3 mol g−1 at 25 °C and 2.8 × 10–5 mol g−1 at 55 °C, respectively. The pseudo-second-order model represented the adsorption kinetics well, and the equilibrium isotherm data were better correlated using the Langmuir equation. The newly developed neural model demonstrated a high predictive capacity with an R-value greater than 0.99 and reduced values for mean squared error, root mean squared error, and mean absolute error equal to 0.003, 0.055, and 0.0348, respectively. The genetic algorithm was used to optimize the experimental conditions of the process. In conclusion, the sea bass scales have promising prospects as a low-cost alternative material for removing cationic dyes from aqueous solutions. [ABSTRACT FROM AUTHOR]

In this work, camel bone biowaste and fish scales were used as a source for the production of hydroxyappatite. Hydroxyapatite (HAP) was extracted from fish scales (FS) and camel bone meal (CBM) using the alkaline heat treatment method. The HAP prepared was analyzed by different characterization techniques such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transformation Infrared spectroscopy (FTIR), Energy Dispersive X-ray spectroscopy (EDS) and Brunauer-Emmett-Teller (BET) analysis. The HAP developed from FS and CBM biomaterials was used as a highly effective green adsorbent to eliminate bisphenol A (BPA) from water. The pseudo-second-order and Langmuir models were well fitted with the kinetic and adsorption isotherm data, with a maximum adsorption capacity of 74.128 and 89.828 mg/g, respectively for FS and CBM. The BPA adsorption on FS and CBM were optimized by the surface response methodology and the Box Behnken Design (RSM@BBD). The optimal factors were obtained to be for FS (% Removal = 83.51%), an adsorbent dose of 1.375 g/L, C i of 5 mg/L and contact temp 115.6 min and for CBM (% Removal = 79.38%) were an adsorbent dose of 1.1 g/L, C i of 6.99 mg/L and contact temp 106.3 min. [ABSTRACT FROM AUTHOR]

Abstract Each year, millions of hatchery‐reared sea‐run brown trout Salmo trutta L. (the sea trout) juveniles are released into the natural environment in the Atlantic region. The aim of this work was to investigate the growth responses of sea trout to changing temperature conditions and to compare the growth plasticity between wild and hatchery‐reared fish. Scales were collected from sea trout in a selected river flowing into the southern Baltic Sea. We analyzed the scale increment widths as a proxy of somatic growth and investigated the interannual variabilities and differences in growth between fish groups (wild and hatchery‐reared). We used mixed‐effects Bayesian modeling and ascribed the variances in growth to different sources. Furthermore, we developed indices of interannual (2003–2015) growth variation in the marine and freshwater phases of the life cycle of the fish and analyzed the relationships between trout growth and temperature. Temperature positively affects fish growth, regardless of the origin of the fish. We observed stronger relationships between fish growth and temperature conditions in the marine phase than in the freshwater phase. Additionally, wild sea trout are characterized by stronger responses to temperature variability and higher phenotypic plasticity of growth than those of the hatchery‐reared individuals. Therefore, wild sea trout might be better suited to changing environmental conditions than hatchery‐reared sea trout. This knowledge identifies possible threats in management actions for sea trout with an emphasis on ongoing climate change.

Atractosteus spatula has been described as a living fossil (having existed for 100 Myr), retaining morphological characteristics of early ancestors such as the ability to breathe air and survive above water for hours. Its highly effective armour consists of ganoid scales. We analyse the protective function of the scales and identify key features which lead to their resistance to failure. Microstructural features include: a twisted cross-plied mineral arrangement that inhibits crack propagation in the external ganoine layer, mineral crystals that deflect cracks in the bony region in order to activate the strength of mineralized collagen fibrils, and saw-tooth ridges along the interface between the two scale layers which direct cracks away from the intrinsically weak interface. The macroscale geometry is additionally evaluated and it is shown that the scales retain full coverage in spite of minimal overlap between adjacent scales while conforming to physiologically required strain and maintaining flexibility via a process in which adjacent rows of scales slide and concurrently reorient.