Fish Fins Research Articles

A Liquid Metal Artificial Muscle.

Artificial muscles possess a vast potential in accelerating the development of robotics, exoskeletons, and prosthetics. Although a variety of emerging actuator technologies are reported, they suffer from several issues, such as high driving voltages, large hysteresis, and water intolerance. Here, a liquid metal artificial muscle (LMAM) is demonstrated, based on the electrochemically tunable interfacial tension of liquid metal to mimic the contraction and extension of muscles. The LMAM can work in different solutions with a wide range of pH (0-14), generating actuation strains of up to 87% at a maximum extension speed of 15 mm s-1 . More importantly, the LMAM only needs a very low driving voltage of 0.5 V. The actuating components of the LMAM are completely built from liquids, which avoids mechanical fatigue and provides actuator linkages without mechanical constraints to movement. The LMAM is used for developing several proof-of-concept applications, including controlled displays, cargo deliveries, and reconfigurable optical reflectors. The simplicity, versatility, and efficiency of the LMAM are further demonstrated by using it to actuate the caudal fin of an untethered bionic robotic fish. The presented LMAM has the potential to extend the performance space of soft actuators for applications from engineering fields to biomedical applications.

Body-caudal fin fish-inspired self-propulsion study on burst-and-coast and continuous swimming of a hydrofoil model

The present study examines the energy efficiency of self-propelled hydrofoils for various modes and kinematics of swimming adopted by various body-caudal fin fish. In particular, this work considers the intermittent burst-and-coast (B&C) and continuous swimming modes, and examines the effect of the undulating and/or pitching swimming kinematics, adopted by the undulating body of anguilliform fish and pitching caudal fin of carangiform and thunniform fish. Notably, B&C swimming is adopted in nature mostly by the latter class but rarely by the former. This fact forms the basis of our study on the hydrodynamics and propulsion performance for both classes of fish-inspired swimming using a NACA0012 hydrofoil model. This analysis explores a large parameter space covering undulation wavelength, 0.8≤λ*<∞, Reynolds number, 50≤Ref≤1500, and duty cycle (DC), 0.1≤DC≤1, with the DC representing the fraction of time in B&C swimming. The fluid–structure dynamics-based vortex-shedding-process is investigated, where B&C swimming results in either an asymmetric reverse von Karman (RVK) or forward von Karman vortex street, rather than a symmetric RVK vortex street observed during continuous swimming. It is demonstrated that the B&C swimming results in an energy saving, although there is a concomitant increase in the travel time. Moreover, our results show that B&C swimming is effective for carangiform and thunniform tail-like kinematics but not for anguilliform body-like kinematics of the hydrofoil. Thus, the predictions are consistent with the observed swimming behavior adopted by a fish in nature and provide input into the efficient design of unmanned underwater vehicles.

Local immune responses to two stages of Ichthyophthirius multifiliis in ginbuna crucian carp

Ichthyophthirius multifiliis is a ciliated protozoan parasite and is known to infect many freshwater teleosts. Characterizing the immune system in epithelial tissues, where the parasites penetrate and settle, is key to understanding host–parasite interactions. This study examined local immune responses in vivo to the infective stage (theront and trophont) of the parasites using intra-fin administration, which has been developed to analyze in vivo immune responses using fish fin. CD8α+ and CD4+ T-cell compositions were increased significantly in the fin cavity injected with theront or trophont antigens. The expression of GATA-3 and T-bet mRNA, which regulate differentiation of helper T-cells, was upregulated significantly in leukocytes from the trophont antigen–injected site. In contrast, the percentages of macrophages and neutrophils, which are innate immunity components, were decreased significantly in the injection sites. These results suggest that I. multifiliis antigens inhibit the migration of macrophages and neutrophils, and T-cells are the first responders to I. multifiliis. Thus, to better understand the interaction of host immunity and I. multifiliis, further studies should focus on exploring the inhibitory factors from I. multifiliis or examining innate functions of teleost T-cells.

Segmentations in fins enable large morphing amplitudes combined with high flexural stiffness for fish-inspired robotic materials.

Fish fins do not contain muscles, yet fish can change their shape with high precision and speed to produce large and complex hydrodynamic forces-a combination of high morphing efficiency and high flexural stiffness that is rare in modern morphing and robotic materials. These "flexo-morphing" capabilities are rare in modern morphing and robotic materials. The thin rays that stiffen the fins and transmit actuation include mineral segments, a prominent feature whose mechanics and function are not fully understood. Here, we use mechanical modeling and mechanical testing on 3D-printed ray models to show that the function of the segmentation is to provide combinations of high flexural stiffness and high morphing amplitude that are critical to the performance of the fins and would not be possible with rays made of a continuous material. Fish fin-inspired designs that combine very soft materials and very stiff segments can provide robotic materials with large morphing amplitudes and strong grasping forces.

Using fin ray chemistry to discriminate hatchery reared juvenile age-0 Persian sturgeons by their origin in the Southern Caspian Sea region using split stream ICP-MS/MC ICP-MS

Trace elements integrated into fish fin rays from the ambient environment may represent a permanent record of the environmental conditions that an individual has experienced throughout its lifetime. Fish from hatcheries used for stocking may therefore carry a natural intrinsic tag of their origin, which can be then later used for assessing the efficiency of stocking measures. This study investigated the potential of the elemental and strontium isotope (n(87Sr)/n(86Sr)) composition of fin rays of juvenile Persian sturgeons (Acipenser persicus) to determine their origin. Water and pectoral fin ray samples of twenty age-0 juvenile Persian sturgeons were collected from the largest hatcheries in the east and west of the Southern Caspian Sea region. The elemental content and the Sr isotope ratio in water were determined by (multi collector) inductively coupled plasma mass spectrometry ((MC) ICP-MS), while the elemental content in fin rays (Ba, K, Mg, Mn, Na, Sr) together with the Sr isotope ratio were determined using laser ablation split stream ICP-MS/MC ICP-MS. The elemental composition of Al, B, Ba, Ca, Cu, Fe, Ga, Li, Mg, Mn, Mo, Na, Pb, Rb, Sr, Tl, U and Zn and the Sr isotope ratio of water differed between the investigated hatcheries from the east and west of the Southern Caspian Sea region. Fin rays reflected the elemental (Sr, Ba and Mn) and the Sr isotope composition of pool water of their hatchery of origin. A factor analysis yielded one main factor (high in Sr content and in the n(87Sr)/n(86Sr) ratio and low in Ba and Mn content) discriminating fin ray samples between sites explaining 86 % of the variation. A discrimination analysis by cross-validated classification yielded 100 % correct assignments of fin ray samples to the hatchery sites using all different parameter combinations. These results suggested that the Sr, Ba Mn elemental and Sr isotope composition of fin rays can be used for the determination of the source hatchery of stocked fish. This represents a valuable tool for evaluation restocking measures of Persian sturgeons in the Southern Caspian Sea region.

Development of the Pectoral Lobed Fin in the Australian Lungfish Neoceratodus forsteri

The evolutionary transition from paired fins to limbs involved the establishment of a set of limb muscles as an evolutionary novelty. In parallel, there was a change in the topography of the spinal nerves innervating appendicular muscles, so that distinct plexuses were formed at the bases of limbs. However, the key developmental changes that brought about this evolutionary novelty have remained elusive due to a lack of data on the development of lobed fins in sarcopterygian fishes. Here, we observed the development of the pectoral fin in the Australian lungfish Neoceratodus forsteri (Sarcopterygii) through synchrotron radiation X-ray microtomography. Neoceratodus forsteri is a key taxon for understanding the fin-to-limb transition due to its close phylogenetic relationships to tetrapods and well-developed lobed fins. At the onset of the fin bud in N. forsteri, there is no mesenchyme at the junction between the axial body wall and the fin bud, which corresponds to the embryonic position of the brachial plexus formed in the mesenchyme in tetrapods. Later, concurrent with the cartilage formation in the fin skeleton, the fin adductor and abductor muscles become differentiated within the surface ectoderm of the fin bud. Subsequently, the girdle muscle, which is homologous to the tetrapod serratus muscle, newly develops at the junction between the axial body wall and the fin. Our study suggests that the acquisition of embryonic mesenchyme at the junction between the axial body wall and the appendicular bud opened the door to the formation of the brachial plexus and the specialization of individual muscles in the lineage that gave rise to tetrapods.

Effects of gradual flexibility and trailing edge shape on propulsive performance of pitching fins

This paper addresses hydrodynamic performance of fins regarding their trailing edge convexity–concavity and flexibility distribution. The effects of trailing edge convexity–concavity on propulsive performance and vortex dynamics were investigated experimentally utilizing time-resolved particle image velocimetry and force sensors. It was found that the convex trailing edge shape always outperforms the concave shape. Wake contracting by the bent shape of the trailing edge vortex of a convex trapezoidal form resulted in higher thrust and efficiency. The results also showed that the rounded edges of fish fins did not provide additional hydrodynamic advantages. Furthermore, we found that a gradually flexible fin delivered better propulsive performance over a uniformly flexible fin. The hydrodynamic performance of the flexible fins depended on the strength and relative positions of the trailing edge vortexes shed by each fin, which were affected by the flexible deformations of the fins. In the lower Reynolds number operation (approaching, but below the first resonant mode), the fins with larger camber produced a stronger momentum footprint especially considering the far wake elements, while in the higher Reynolds number range due to resonant deformation the extent of trailing edge excursion became dominant in affecting the propulsive performance. The results showed that gradually flexible fins can improve the performance of future watercraft.

Learning from nature for healthcare, energy, and environment

Learning from nature for healthcare, energy, and environment

Longfin causes cis-ectopic expression of the kcnh2a ether-a-go-go K+ channel to autonomously prolong fin outgrowth.

Organs stop growing to achieve a characteristic size and shape in scale with the body of an animal. Likewise, regenerating organs sense injury extents to instruct appropriate replacement growth. Fish fins exemplify both phenomena through their tremendous diversity of form and remarkably robust regeneration. The classic zebrafish mutant longfint2 develops and regenerates dramatically elongated fins and underlying ray skeleton. We show longfint2 chromosome 2 overexpresses the ether-a-go-go-related voltage-gated potassium channel kcnh2a. Genetic disruption of kcnh2a in cis rescues longfint2, indicating longfint2 is a regulatory kcnh2a allele. We find longfint2 fin overgrowth originates from prolonged outgrowth periods by showing Kcnh2a chemical inhibition during late stage regeneration fully suppresses overgrowth. Cell transplantations demonstrate longfint2-ectopic kcnh2a acts tissue autonomously within the fin intra-ray mesenchymal lineage. Temporal inhibition of the Ca2+-dependent phosphatase calcineurin indicates it likewise entirely acts late in regeneration to attenuate fin outgrowth. Epistasis experiments suggest longfint2-expressed Kcnh2a inhibits calcineurin output to supersede growth cessation signals. We conclude ion signaling within the growth-determining mesenchyme lineage controls fin size by tuning outgrowth periods rather than altering positional information or cell-level growth potency.

Basal epidermis collective migration and local Sonic hedgehog signaling promote skeletal branching morphogenesis in zebrafish fins

Teleost fish fins, like all vertebrate limbs, comprise a series of bones laid out in characteristic pattern. Each fin's distal bony rays typically branch to elaborate skeletal networks providing form and function. Zebrafish caudal fin regeneration studies suggest basal epidermal-expressed Sonic hedgehog (Shh) promotes ray branching by partitioning pools of adjacent pre-osteoblasts. This Shh role is distinct from its well-studied Zone of Polarizing Activity role establishing paired limb positional information. Therefore, we investigated if and how Shh signaling similarly functions during developmental ray branching of both paired and unpaired fins while resolving cellular dynamics of branching by live imaging. We found shha is expressed uniquely by basal epidermal cells overlying pre-osteoblast pools at the distal aspect of outgrowing juvenile fins. Lateral splitting of each shha-expressing epidermal domain followed by the pre-osteoblast pools precedes overt ray branching. We use ptch2:Kaede fish and Kaede photoconversion to identify short stretches of shha+basal epidermis and juxtaposed pre-osteoblasts as the Shh/Smoothened (Smo) active zone. Basal epidermal distal collective movements continuously replenish each shha+domain with individual cells transiently expressing and responding to Shh. In contrast, pre-osteoblasts maintain Shh/Smo activity until differentiating. The Smo inhibitor BMS-833923 prevents branching in all fins, paired and unpaired, with surprisingly minimal effects on caudal fin initial skeletal patterning, ray outgrowth or bone differentiation. Staggered BMS-833923 addition indicates Shh/Smo signaling acts throughout the branching process. We use live cell tracking to find Shh/Smo restrains the distal movement of basal epidermal cells by apparent ‘tethering’ to pre-osteoblasts. We propose short-range Shh/Smo signaling promotes these heterotypic associations to couple instructive basal epidermal collective movements to pre-osteoblast repositioning as a unique mode of branching morphogenesis.

Characterization of Charcoal From Kerandang (Channa pleurophthalma Bleeker) Fish Fins Waste As A Source of Hydroxiapatite

This study aims to characterize the charcoal from the fins waste of the Kerandang fish, namely from the dorsal (DF), pectoral (PF), ventral (VF), anal (AF), and caudal fin (CF). The charcoal as a source of hydroxyapatite. Qualitative characterization used a Scanning Electron Microscope (SEM), Fourier Transfer Infra-Red (FTIR), and X-Ray Diffraction (XRD). The charcoal’s chemical composition consists of Carbon, Oxygen, Sodium, Magnesium, Phosphor, Sulfur, and Chlorine, Potassium, and Calcium. The highest carbon element was 67.74% in the caudal fins. The lowest chemical element in the element sulfur is 0.197% in the dorsal fins. SEM photos show that the charcoal from the caudal fins has more pores than the other fins. The FTIR results show that the functional groups contained in the charcoal from the fins are NH, OH, CO, C=O, C=C, S1-O, and CH groups, with wave numbers 1032-1036 cm−1. The absorption area of the S1-O group (silica), where the silica group from charcoal, has the highest intensity. XRD results showed that the charcoal from fish fins of Kerandang contained 100% hydroxyapatite.

Chemical Composition of Lizardfish Surimi By-Product: Focus on Macro and Micro-Minerals Contents

Surimi processing industries generated over 60% of fish by-products, including head, skin, viscera, trimming, bone, scale, and fin. Hence, an effort converting these by-products into valuable compounds and constituents is necessary for optimizing the resources. In order to implement this, the information on the chemical composition of the by-products is helpful. This study aimed to determine the chemical composition, particularly minerals of lizardfish surimi by-products. The protein, fat, ash, moisture, and carbohydrate values of by-products differed significantly (p < 0.05). Protein content was highest in the skin and scale (29.63% and 29.62%, respectively), and ash content was predominantly found in the scale (28.43%), fin (26.01%), and bone (23.58). Calcium, magnesium, potassium, and sodium content were significantly varied respectively from 0.25% to 6.88%, 0.06% to 0.37%, 0.01% to 0.09%, and 0.01% to 0.32%. Calcium is highest in scale, whereas zinc, manganese, and iron were most abundance in all parts of the by-products sample. Zinc is mostly detected in the fin (76.75 µg/g), bone (48.67 µg/g) and scale (46.01 µg/g) parts. On the other hand, copper, chromium, selenium, cadmium and lead were detected at lower concentration (less than 2 µg/g), and complied with the safety levels set by the Malaysian Food and Regulations. These findings suggest that, by-products generated from lizardfish surimi processing may be used as ingredients to enrich nutritional value of other food products.

Evaluation of muscle lipid extraction and non‐lethal fin tissue use for carbon, nitrogen, and sulfur isotope analyses in adult salmonids

RationaleChemical lipid extraction or using alternative tissues such as fish fin as opposed to muscle may alter isotopic ratios and influence interpretations of δ13C, δ15N, and previously unassessed δ34S values in stable isotope analyses (SIA). Our objectives were to determine if lipid extraction alters these isotope ratios in muscle, if lipid normalization models can be used for lipid‐rich salmonids, and if fin isotope ratios are comparable with those of muscle in adult salmonids.MethodsIn six adult salmonid species (n = 106) collected from Lake Ontario, we compared three isotope ratios in lipid‐extracted (LE) muscle with bulk muscle, and LE muscle with fin tissue, with paired t‐tests and linear regressions. We compared differences between δ13C values in LE and bulk muscle with predicted values from lipid normalization models and the log‐linear model of best fit and determined model efficiency.ResultsThe δ15N values in LE muscle increased (<1‰) relative to bulk muscle for most salmonids, with relationships nearing 1:1. There were either no differences or strong 1:1 relationships in δ34S values between species‐specific bulk and LE muscle. One lipid normalization model had greater model efficiency (97%) than the model of best fit (94%). Fin had higher δ13C values than LE muscle while δ15N trends varied (<1‰); however, both isotope ratios had either no or weak linear relationships with fin and LE muscle within species. The δ34S values in fin were similar to those in LE muscle and had strong 1:1 relationships across species.ConclusionsWe recommend using the lipid normalization model to adjust for δ13C values in lipid‐rich muscle (C:N >3.4). LE muscle could be used without δ15N or δ34S adjustments, but the minimal increase in δ15N values may affect SIA interpretation. With high unexplained variability among adult species in fin‐muscle δ13C and δ15N relationships, species‐specific fin‐muscle adjustments are warranted. No fin‐muscle tissue adjustment would be required for δ34S values.

Sharpshooting archerfish brake to overcome recoil

Assassins come in all shapes and forms; some lurk, while others prowl. Archerfish, in contrast, simply float benignly in their mangrove homes until a tasty fly catches their eye. Then they transform into lethal marksmen. ‘Archerfish down a variety of aerial prey from a range of distances using water jets that they adjust to the size and distance’, says Stefan Schuster from the University of Bayreuth, Germany, who has spent much of the past two decades painstakingly unravelling how the meticulous sharpshooters target their victims. It was only when Schuster and Peggy Gerullis were investigating how the fish manoeuvre their mouths to optimise the lethal pulse of water that they noticed that the fishy snipers shimmy their pectoral fins at the precise instant they let fly a jet of water. ‘Their rapid forward flap appeared quite silly’, laughs Schuster, recalling how the fish only initiated the movement once stationary. Most intriguingly, the fin manoeuvre appeared to be in the wrong direction to prevent the fish from shooting backward. They appeared to be braking, but in the wrong direction. ‘There was something curious that needed a closer look’, says Gerullis.Fortunately, she had already trained two of the fish to take fire at tiny target spheres from a channel in their tank, where she could film their fin movements in 3D. ‘Archerfish are wonderful to work with – they readily shoot at everything, including things you did not intend to be targets’, Gerullis laughs. Painstakingly reconstructing the fin movements during 278 archerfish hits, she, Schuster and Caroline Reinel realised that the fish begin to sweep their pectoral fins forward in the final 40 ms before water starts spouting from their mouths, with the fins reaching their fastest rotation, ∼1000 deg s−1, just after the jet begins to emerge. And, as Gerullis raised the targets and the fish adjusted their aim, the animals swung the pectoral fins faster and returned them to their sides sooner, in addition to synchronising the pectoral fins’ movements perfectly. In contrast, the fish rotated their pelvic fins wide for stability well in advance of letting rip with a gush of water and coordinated their dorsal and tail fin sweeps in opposite directions in time with the jet. ‘We were impressed that all of the fish's fins were involved’, Schuster recalls.So how were the fish able to remain perfectly static at the water's surface while their fins were working in harmony at the precise instant when letting loose a bolt of water? Looking at the upward-directed jet, Schuster realised that the fish weren't only in danger of being blown backward by the recoil, they were at an even greater risk of being submerged as the blast threw them down in the water. ‘The forces produced during the forward flap must produce sufficient lift to keep the shooter at the surface’, Gerullis explains.But was this just a neat party trick by Gerullis's well trained sharpshooters, or would archerfish that were free to choose when and where they took aim also perform a fin shimmy? Fortunately, Reinel had hours of fin manoeuvre movies that she had never scrutinised, collected while she investigated the fish's fly-retrieval strategy. ‘Caroline scrutinised an impressive number of her recordings’, Schuster says. Sure enough, her free-form archerfish also performed the enigmatic fin flaps that allowed their trained cousins to remain in position at the surface.So, squirting archerfish keep themselves in place with a quick lift-generating wave of the fins and Schuster is eager to find out how they fine-tune the fin manoeuvre when taking high and low pot shots.

The Fish Family Poeciliidae as a Model to Study the Evolution and Diversification of Regenerative Capacity in Vertebrates

The capacity of regenerating a new structure after losing an old one is a major challenge in the animal kingdom. Fish have emerged as an interesting model to study regeneration due to their high and diverse regenerative capacity. To date, most efforts have focused on revealing the mechanisms underlying fin regeneration, but information on why and how this capacity evolves remains incomplete. Here, we propose the livebearing fish family Poeciliidae as a promising new model system to study the evolution of fin regeneration. First, we review the current state of knowledge on the evolution of regeneration in the animal kingdom, with a special emphasis on fish fins. Second, we summarize recent advances in our understanding of the mechanisms behind fin regeneration in fish. Third, we discuss potential evolutionary pressures that may modulate the regenerative capacity of fish fins and propose three new theories for how natural and sexual selection can lead to the evolution of fin regeneration: (1) signaling-driven fin regeneration, (2) predation-driven fin regeneration, and (3) matrotrophy-suppressed fin regeneration. Finally, we argue that fish from the family Poeciliidae are an excellent model system to test these theories, because they comprise of a large variety of species in a well-defined phylogenetic framework that inhabit very different environments and display remarkable variation in reproductive traits, allowing for comparative studies of fin regeneration among closely related species, among populations within species or among individuals within populations. This new model system has the potential to shed new light on the underlying genetic and molecular mechanisms driving the evolution and diversification of regeneration in vertebrates.

The Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies Agent

societies of the Central Kalimantan have a traditional treatment for skin allergies derived from charcoal. charcoal was obtained from the fin waste of Channa pleurophthalma fish. present study aimed to analyze the bioactive compounds of Channa pleurophthalma fin waste charcoal (CFWC) and determine the biological potential using bioinformatics methods and visual empirical evidence approach. Bioactive substances were screened using LC-HRMS. 2D structure and 3D structure of bioactive compounds were obtained from PubChem. PASSOnline was applied to analyze the prediction of hydrolyzed compounds biological activity. There were 10 highest compounds in CSWC: octyl decyl phthalate, hexadecanamide, oleamide, cetrimonium, dibutyl phthalate, pyroquilon, stearamide, 6-methoxyquinoline, 8-hydroxyquinoline and tridemorph. CSWC has potential effect as anti-allergies, anti-inflammation, anti-pruritic, anti-fungi, and anti-microbe. CFWC also could heal the wound of allergies for seven days. In conclusion, CFWC could be an effective treatment to heal skin wounds due to the allergy of Channa pleurophthalma. How to Cite this Article Pubmed Style , Riyadi PH. Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies SRP. 2020; 11(7): 26-31. doi:10.31838/srp.2020.7.06 Web Style , Riyadi PH. Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies http://www.sysrevpharm.org/?mno=113696 [Access: March 30, 2021]. doi:10.31838/srp.2020.7.06 AMA (American Medical Association) Style , Riyadi PH. Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies SRP. 2020; 11(7): 26-31. doi:10.31838/srp.2020.7.06 Vancouver/ICMJE Style , Riyadi PH. Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies SRP. (2020), [cited March 30, 2021]; 11(7): 26-31. doi:10.31838/srp.2020.7.06 Harvard Style & Riyadi, . P. H. (2020) Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies SRP, 11 (7), 26-31. doi:10.31838/srp.2020.7.06 Turabian Style , and Putut Har Riyadi. 2020. Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies Systematic Reviews in Pharmacy, 11 (7), 26-31. doi:10.31838/srp.2020.7.06 Chicago Style , and Putut Har Riyadi. The Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies Agent. Systematic Reviews in Pharmacy 11 (2020), 26-31. doi:10.31838/srp.2020.7.06 MLA (The Modern Language Association) Style , and Putut Har Riyadi. The Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies Agent. Systematic Reviews in Pharmacy 11.7 (2020), 26-31. Print. doi:10.31838/srp.2020.7.06 APA (American Psychological Association) Style & Riyadi, . P. H. (2020) Effectivity of Kerandang Fish (Channa pleurophthalma Blkr) Fin Waste as an Anti-Skin Allergies Systematic Reviews in Pharmacy, 11 (7), 26-31. doi:10.31838/srp.2020.7.06

Enhancement of Labriform Swimming Robot Performance Based on Morphological Properties of Pectoral Fins

A swimming performance underlies the biomechanical properties and functional morphology of fish fins. Recently, one of the major fields of robotics researchers' interest, is how to resolve some of the difficulties associated with the different water environments like ponds, lagoons, rivers, and deep water or even shallow, sometimes, exploration and searching in many of these environments tend to be dangerous or inaccessible to man. Thus, it is important to develop an efficient technology with direct applications as a solution to the problems appointed such as the use of swimming robots. In this research, design and realization of a swimming robot propelled by a pair of pectoral fin are implemented. The complete design of the swimming robot body is presented. Next, the effect of varying fin oscillation speed in two phases will be observed, the first phase is the power stroke one, where the fins start to push toward the backward of the body, and the recovery phase, where the fins return toward the frontal part of the body. The detailed steps of the robot design are presented and the thrust force exerted by pectoral fins has been evaluated. The suggested swimming robot is a rigid-body with an elliptical cross-sectional area, which helps in minimizing the water resistance during the thrusting process. To improve the system performance, the kinematic and dynamic model of a swimming robot has been derived based on Newton–Euler equations, while an evaluation of the total hydrodynamic forces that are exerted on the swimming robot’s body is studied via the computational fluid dynamics method. Further, a proportional integral derivative controller has been suggested for motion controlling. The proposed design has been validated theoretically via SOLIDWORKS® platform and examined experimentally by several experiments. The results of the simulation and practical experiments showed the validity of the proposed system as a labriform swimming robot.

Seafood Waste Management Status in Bangladesh and Potential for Silage Production

Frozen shrimp and fish are the second most valuable export items from Bangladesh. Thus, in processing industries, a considerable amount of seafood waste is produced every year. Neglecting seafood waste leads to serious forms of wastage. The purpose of this survey-based study was to estimate the amount of seafood waste produced and understand the existing waste management practices in Bangladesh. Potential for seafood waste-based silage production and its utilization were also studied. Across the seafood industry, around 43,321 tons of seafood waste are produced every year. The highest amount of seafood waste is produced in Khulna, followed by Chittagong, Cox’s Bazar, Dhaka, and Sylhet. Local people consume a portion of fresh shrimp carapace and heads and gills of large fish. A portion of seafood waste is also used to feed aquaculture species. Moreover, parts of dried shrimp shells, appendages, and fish scales, air bladders, and fins are exported to some Asian countries. The prospect of fish silage production constitutes a promising new development for animal feed production in Bangladesh. The availability of waste materials from seafood processors and the demand from feed millers favor the conditions for silage production. However, in order for the seafood waste-based silage industry to flourish, the establishment of supply chains for seafood waste and end products (silage) is required. Studies on growth performance, muscle quality, and digestibility of animal feed with silage-based diets are required for farmed species.

Developmental hourglass and heterochronic shifts in fin and limb development.

How genetic changes are linked to morphological novelties and developmental constraints remains elusive. Here, we investigate genetic apparatuses that distinguish fish fins from tetrapod limbs by analyzing transcriptomes and open-chromatin regions (OCRs). Specifically, we compared mouse forelimb buds with the pectoral fin buds of an elasmobranch, the brown-banded bamboo shark (Chiloscyllium punctatum). A transcriptomic comparison with an accurate orthology map revealed both a mass heterochrony and hourglass-shaped conservation of gene expression between fins and limbs. Furthermore, open-chromatin analysis suggested that access to conserved regulatory sequences is transiently increased during mid-stage limb development. During this stage, stage-specific and tissue-specific OCRs were also enriched. Together, early and late stages of fin/limb development are more permissive to mutations than middle stages, which may have contributed to major morphological changes during the fin-to-limb evolution. We hypothesize that the middle stages are constrained by regulatory complexity that results from dynamic and tissue-specific transcriptional controls.

Updating specific PCR primer for detection of Cryptocaryon irritans from reared Larimichthys polyactis

Artificial breeding of small yellow croaker (Larimichthys polyactis) was recently achieved, providing a bright future for its commercial farming. In May 2019, a disease outbreak occurred among small yellow croakers in an aquaculture farm near Xiangshan Bay, charactering by white spots spotted on the surface of fish skin, gills and fins. The parasite was preliminarily identified as Cryptocaryon irritans based on morphological feature of the parasite and the symptoms on fish. However, the previously published specific primer pairs failed to confirm the existence of C. iriitans. Six nucleotides mismatches were discovered after mapping specific forward primer back to targeted gene. Therefore, an updated PCR specific primer was developed within the 9th highly variable region of 18S rRNA gene and conserved in all C. irritans sequences available in GenBank database. The specificity was verified in silico by Primer-BLAST against GenBank nucleotide. Laboratory cultured ciliates (Mesanophrys, Pseudokeronopsis and Uronema) as well as natural microbial community samples collected from sea water and river water was used as negative control to verify the specificity of the primer in situ. Besides, tank transfer method was used to evaluate the treatment of the parasite infection. By tank transfer method, 2.00 ± 0.61 out of 10 fish that already sever infected were successfully survived after 8 days treatment, meanwhile the control group died out at d 6. More loss to the treatment group during first five days was observed and may attribute to the combined effect from infection and stress the recent domesticated fish suffered during rotation. Therefore, tank transfer method was also effective to prevent small yellow croaker from further infection, however the loss of the small yellow croaker suffered from stress during rotation also needs to be carefully concerned. In conclusion, this study reported the first diagnose of C. irritans infection on small yellow croaker, provided updated specific primer to detect C. irritans infection on fish body and reported the effect of tank transfer on small yellow croaker treatment.