Primary Filaments Research Articles

PETG as an Alternative Material for the Production of Drone Spare Parts.

Material selection is the main challenge in the drone industry. In this study, hardness, abrasive wear, impact resistance, tensile strength, and durability (frost resistance and accelerated ageing) were identified as important characteristics of drone materials. The additive manufacturing technology was used to produce the drone leg specimens and prototype. The suitability of PETG as a primary filament material in the design of the drone leg was investigated. Nine series were printed with different raster lines (0.1, 0.2 and 0.3 mm) and infill densities (30, 60 and 90%). Printed specimens were annealed in salt and alabaster, as well as immersed in liquid nitrogen. Series with raster line-infill densities of 0.1-30, 0.3-30, 0.1-90 and 0.3-90 were identified as the most interesting ones. Thermally treated specimens had better mechanical and durability properties, and infill density was found to be the most important printing parameter. Specimen annealed in salt with a raster line of 0.1 mm and infill density of 90% had the best results. Since ABS is the most common material used for drone leg production, its properties were compared with the PETG specimen, which showed the best properties. The potential of PETG as an alternative material was proven, while the flexibility, productivity and suitability of the leg drone design were additionally confirmed.

Effects of External Magnetic Field on Focusing and Energy Distribution of Primary Electrons in an Ion Source

The effect of the applied voltage and magnetic field on the defining slot in focusing and energy distribution of the primary filament electron beam was studied theoretically. In this work, SIMION 8.1 software was used to determine the best operational conditions for focusing and the distribution of the electron beam in the ion source system. Furthermore, the Larmor radius on the slot was calculated in two dimensions for different values of magnetic flux density. The results showed that the values of flux density and slot voltage play an effective role in improving the dimensions of beam spot andenergy distribution in the source. The dimensions of beam spot were reduced by about 71% at voltage value of slot 75 volt and flux density 780 G. In addition; the kinetic energy distribution for electrons were computed at different magnetic flux and obtaining a homogeneous beam energy. The results of this research support the calculations of plasma source designers.

Chlorella filled poly(lactic acid) (PLA)/poly(butylene adipate-co-terephthalate) (PBAT) blend bio-composites compatible with additive manufacturing processes: Fluorescent and anti-counterfeiting QR codes applications

Anti-counterfeiting in 3D printing has gained significant attention, however, current approaches often fall short of fully capitalizing on the inherent advantages of personalized manufacturing with this technology. Herein, we propose an embedded anti-counterfeiting scheme for additive manufacturing, accompanied by a novel fluorescent encrypted quick response (QR) method. This approach involves the development of a 3D printing filament utilizing poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) bio-composites as the primary filament matrix, with varying quantities of Chlorella powder incorporated. The resulting filament has a good thermal stability near 200 °C and exhibits a distinctive red fluorescence under ultraviolet light, with the emission peak at 677 nm when excited by 415 nm blue light. Fluorescence imaging analysis confirms that the red fluorescence in 3D printed devices containing Chlorella is a result of the chlorophyll and its derivatives fluorescence effect. The fluorescent encrypted QR codes are inconspicuous in daylight but become easily discernible under ultraviolet light. In the cases of recognizable QR codes, the ∆Eab* values all exceed 35, and the LC/LB values deviate significantly from 1. This research delves into the fluorescence characteristics of Chlorella and highlights its applicability in 3D printing, specifically within the realm of product anti-counterfeiting, presenting a groundbreaking approach.

Combined effects of water salinity and ammonia exposure on the antioxidative status, serum biochemistry, and immunity of Nile tilapia (Oreochromis niloticus).

Growing Nile tilapia in brackish water showed promising results, but the possibility of ammonia exposure can interrupt health status and productivity. Herein, the study tested the combined effects of water salinity and ammonia exposure on the antioxidative status, serum biochemistry, and immunity of Nile tilapia. Fish were assigned to eight groups where fish were reared in saline water (5, 10, and 15 ppt) with continuous or intermittent (every 3 days) total ammonia (TAN) exposure (5 mg TAN/L) (2 × 4 factorial design). After 30 days, the water salinity, TAN, and their interaction were markedly (P < 0.05), affecting the growth performance (final weight, weight gain, and specific growth rate) and survival rate of Nile tilapia. The growth performance and survival rate were markedly lower in tilapia grown in 15 ppt with continuous TAN exposure than in the remaining groups. The results showed that fish exposed to higher salinity levels (10 and 15 ppt) and continuous TAN exposure had a more robust antioxidative response, as evidenced by higher superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities and lower malondialdehyde (MDA) levels in the homogenates of the gills, intestines, and livers. The gills were notably affected, with congestion of primary filaments blood vessels and degeneration or shedding of secondary filaments epithelium, especially at salinity levels of 10 and 15 ppt. Additionally, the intestines displayed hyperplasia and inflammatory cell infiltration of intestinal mucosa at 5-10 ppt salinity, degeneration and sloughing of the intestinal epithelium at 15 ppt saline water, and increased goblet cell number at salinity of 10 ppt. The study found that continuous TAN exposure had a more significant impact on the fish, especially at higher salinity levels. Water salinity, TAN, and their interaction significantly affected all measured blood bio-indicators (total, albumin, globulin, ALT, AST, creatinine, urea, glucose, and cortisol levels). The phagocytic activity and index were markedly lowered in fish reared in 15 ppt with continuous TAN exposure, while the lysozyme activity was decreased in fish grown in 5, 10, and 15 ppt with continuous TAN exposure. In conclusion, Nile tilapia showed the possibility of growth with normal health status in brackish water (5-10 ppt); however, continuous TAN exposure can impair the productivity of tilapia, especially with high salinity (15 ppt).

Occurrence of Multispecies Myxozoan Parasite Infestation by Genus &lt;i&gt;Thelohanellus&lt;/i&gt; Kudo, 1933 in a Group of &lt;i&gt;Labeo rohita &lt;/i&gt;(Hamilton, 1822)

We describe two Thelohanellus Kudo spp. namely, T. bifurcata (34.94x 8.9μm) on gills and T. caudatus (13x8.9μm) on the caudal and dorsal fins, found infecting Labeo rohita (Hamilton, 1822) fingerlings in a wet lab facility of West Bengal India. The L. rohita fingerlings having spores on fins and gills were segregated and gross pathology was observed for one month. It was done to characterise the morphology of mature spores and to examine the histopathology of infected gills. There were 5-6 white cysts (1-2 mm in length) on the gill filament that were mostly persistent during the one-month study period and infected fish (12.5% prevalent) were listless, anorexic, and emaciated before eventually all of them perished. Spores of 4- 7 mm size in 1-4 numbers were found on caudal and dorsal fins which were visible for two weeks before it gets mature and released, whereas infected fish (20%) were active and underwent normal growth. Additionally, it was discovered that 5% of fingerlings had cysts on their gills and fins. The distal tip of the primary gill lamellae is where the gill epithelium ruptures, releasing the spores. The histological inspection of the infected gill clearly demonstrates infective sporoplasm entry, presporogonic stage, plasmodial maturation, and release of spores. Within a month, it was discovered that 100% of the fingerlings with infected gills died. This is because the plasmodial spores on primary gill filaments damage the structural framework of the gill filament and cause epithelial and vascular cell displacement. Our comparative analysis with previous studies support that orders and families of the parasites are strongly correlated with Thellohanellus Kudo sp: a pathogenic strain of T. bifurcata and a non-pathogenic strain of T. caudatus infecting L. rohita. The spore-forming stages of the gill-damaging T. bifurcata (entry, pre-sporogonic, and sporogonic) are extremely pathogenic to fish fingerlings and cause significant damage to gill tissue

Airfoil-shaped filament feed spacer for improved filtration performance in water treatment

Optimal spacer design enhances the filtration performance in spiral-wound modules by controlling the local hydrodynamics inside the filtration channel. A novel airfoil feed spacer design fabricated using 3D-printing technology is proposed in this study. The design is a ladder-shaped configuration with primary airfoil-shaped filaments facing the incoming feed flow. The airfoil filaments are reinforced by cylindrical pillars supporting the membrane surface. Laterally, all the airfoil filaments are connected by thin cylindrical filaments. The performances of the novel airfoil spacers are evaluated at Angle of Attack (AOA) of 10° (A-10 spacer) and 30° (A-30 spacer) and compared with commercial (COM) spacer. At fixed operating conditions, simulations indicate steady-state hydrodynamics inside the channel for A-10 spacer, while an unsteady state is found for A-30 spacer. Numerical wall shear stress for airfoil spacers is uniformly distributed and has a higher magnitude than the COM spacer. A-30 spacer design is the most efficient in ultrafiltration process with enhanced permeate flux (228%) and reduced specific energy consumption (23%) and biofouling development (74%) as characterized by Optical Coherence Tomography. Results systematically demonstrate the influential role of airfoil-shaped filaments for feed spacer design. Modifying AOA allows localized hydrodynamics to be effectively controlled according to the filtration type and operating conditions.

Hiostopathological studies on gill, liver and brain of oreochromis mossambicus exposed to ethoxyquin

Water pollution greatly affects the life of aquatic ecosystem. Ethoxyquin (EQ) is one such toxic content, which is even present in the food being presented to the aquatic beings. In this research work, the effects of ethoxyquin on the Oreochromis mossambicus, called tilapia fish is studied. The aimed fish species is treated through the sublethal concentration of EQ. The effects of this toxic content on the aspects histopathological parameters were studied and the results were presented. Histopathological analysis was attempted on the gill, liver and brain of the tilapia fish taken up for the study. The histological abnormalities that were seen were curling of secondary lamella, which was followed by disorder and rupture in the secondary lamellae. These changes were more widespread and more apparent in the gills and liver of the Oreochromis mossambicus. A haemorrhage at the main lamellae and a swelling at the primary filament's tip were also seen during the examination. Analysis of the brain, inferred that no severe damages to the neurons are reported. As a conclusion, the results of the current histology examinations reveal that the EQ exposure caused moderate to severe damage to the gills and liver of the O. Mossambicus, whereas only moderate damage to the brain neurons.

Potential biomarker of phenol toxicity in freshwater fish C. mrigala: Serum cortisol, enzyme acetylcholine esterase and survival organ gill

In this modern industrialized era of large-scale production of agrochemicals, various emerging contaminants form the main components of waste water and sludge in most of the developing countries of the world. In this concern, phenol- an inevitable and alarming chemical pollutant in aquatic ecosystem, gains a speedy access into the water bodies as an industrial by-product. Though the detrimental effects of phenol have been studied in various aspects of aquatic life, current study is an initiative to unravel the toxic effects of phenol at molecular level in Cirrhinus mrigala. Plasma cortisol level and acetylcholine esterase activity in fish was estimated by Chemiluminescent immunoassay technique and Ellman assay respectively. Scanning electron microscopic studies were carried out to unravel the gill histopathological alterations in exposed fish. It was observed that phenol (22.32 mg/l) inhibits 50 % of acetylcholine esterase activity in brain thereby affecting the locomotion of the targeted carp. Cortisol elevated during the 7th day in exposed fish, but declined progressively on the forthcoming 21st and 28th days. Manifestations in gill encompass curling, fusion, aberrations, sloughing of gill epithelium, wider inter filamentary space and mucus coating in the primary gill filament. It concludes that the discernable deviations produced in both biochemical parameters and key organ gill can be used as a biomarker and bio-indicator respectively for assessing the existence of emerging toxicants in aquatic ecosystem.

Eradication of Livoneca redmanii infestation in cultured Argyrosomus regius

Two Argyrosomus regius nursery ponds suffered from high mortality during the summer season of 2020. Diseased fish showed signs of respiratory distress, mainly during hot days. Physiochemical pond water parameters were normal, except dissolved oxygen was lower than the optimum level. Livoneca redmanii (Cymotidae, Isopoda) was isolated from the gill chamber of infested fish. The infestation percent was 41 and 33%, and the intensity was 1.146 and 1.06 in the first and second ponds, respectively. The diseased fingerlings were infested in the natural habitat (Mediterranean Sea) before collection for culture. L. redmanii infestation was associated with high economic losses due to direct fish mortality, reduced growth rates and lower condition factor. The molecular study confirmed the presence of L. redmanii based on the phylogenetic analysis of 16S rRNA and COI gene sequences. Infested fish gills showed massive destruction in gill filaments, sloughing and curling of secondary gill lamellae with the detachment of the cartilaginous core supporting the primary gill filaments. Deltamethrin and trichlorfon effectively eradicated L. redmanii at concentrations of 12.5 μg.l−1 and 0.5 mg.l−1, respectively. The lowest detectable deltamethrin residue in treated pond water was 2.18 μg.l−1 at 120 h, with a half-life of 47.63 h.

Cover: Journal of Basic Microbiology. 5/2022

Journal of Basic MicrobiologyVolume 62, Issue 5 p. 531-531 COVER PICTUREFree Access Cover: Journal of Basic Microbiology. 5/2022 First published: 02 May 2022 https://doi.org/10.1002/jobm.202270008AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract Cover illustration: Neowestiellopsis strain derived from the Cholistan desert (Pakistan) displaying uniseriate primary filament with branches arising in both directions, a heterocyst, profuse growth of secondary branches with protruding basal cells. (Photo: Abdul Samad Mumtaz, Department of Plant Sciences, Quaid-i-Azam University, Islamabad, Pakistan) Volume62, Issue5Special Focus: Cell walls and extracellular mechanismsMay 2022Pages 531-531 RelatedInformation

Study of Histopathological change in gills of Coptodon zillii as a bioindicator of pollution in Sarragy River In Abu Alkhasiib region

In the present study the fish Coptodon zillii are collectedfrom Sarragy River in Abu Alkhasiib region through two season that the first is expansion from 7\2013 to 11\2013 and the second season is expansion from 12\2013 to 6\2014,and bringing it to the laboratory for dissection and ablation the gills for studied the histopathological change that appear on it, that included change of the form of some secondary lamellae, adherence in other secondary lamella ,cellular hyperplasia , hypertrophy , swelling in the epithelial layer of secondary lamellae, epithelial lifting ,and hyperplasia in cartilage skeletal of primary filaments.

Acute ammonia exposure combined with heat stress impaired the histological features of gills and liver tissues and the expression responses of immune and antioxidative related genes in Nile tilapia

Ammonia exposure can be considered more stressful for aquatic animals when it coincides with high temperature. This study was conducted to detect the effects of ammonia exposure and heat stress and their interactions on the histological features of gills and liver tissues and the expression responses of immune and antioxidative related genes in Nile tilapia. Thus, 180 fish were divided into four groups (triplicates), where the first and third groups were kept in clean water without total ammonium nitrogen (TAN) exposure. At the same time, the second and fourth groups were exposed to 5 mg TAN/L. After seven days, the water temperature was raised in the third (without ammonia toxicity) and fourth (exposed with 5 mg TAN/L) groups up to 32 °C and kept under these conditions for 24 h. While the first (without ammonia toxicity) and second (exposed with 5 mg TAN/L) groups were kept under optimum water temperature (27.28 °C) then gills and liver tissues were dissected. Marked upregulation of keap1 was seen in the gills of fish exposed to ammonia/heat stress. The expression of mRNA levels for nrf2, nqo-1, cat, and gpx genes were downregulated in all stressed groups, with the lowest was recorded in the ammonia/heat stress group. The transcription of ho-1 was upregulated in the ammonia and heat stress groups while downregulated in the ammonia/heat stress group. The transcription of the complement C3 gene was downregulated in the livers of heat stress and ammonia/heat stress groups, while the lysozyme gene was downregulated in the ammonia/heat stress group. The mRNA expression levels of nf-κB, il-1β, and tnf-α genes were higher in the ammonia group than in the heat stress group. The highest transcription level of nf-κB, il-1β, tnf-α, il-8, and hsp70 genes and the lowest C3 and lysozyme genes were observed in fish exposed to ammonia/heat stress. The co-exposure to ammonia with heat stress triggered degeneration of primary and secondary gill filaments with telangiectasia and vascular congestion of secondary epithelium while, the liver showed hepatic vascular congestion and visible necrotic changes with nuclear pyknosis. In conclusion, the combined exposure of ammonia and heat stress induced oxidative stress, immunosuppression, and inflammation in Nile tilapia.

Oskar Balığının (Astronotus ocellatus) Solungaçlarında Glikokonjugatların Dağılımı

Glycoconjugates involved in many functions are produced by many cell types. This study aimed to investigate the glycoconjugate expression in the Oscar fish (Astronotus ocellatus) gills using five horseradish peroxidase-conjugated lectins. This study revealed that gill epithelial cells react with Canavalia ensiformis agglutinin (Con A) and Arachis hypogaea agglutinin (PNA). Strong reaction to Con A was seen in the epithelial cells of the gill primary lamellae. Epithelial cells of primary and secondary lamellae and eosinophilic granular cells had varying intensity of PNA binding. Ulex europaeus agglutinin-I(UEA-I) positive eosinophilic granular cells were observed in the connective tissue of primary lamellae. Epithelial cells of the gill primary filament had Con A reaction in varying intensities. Superficial epithelial cells reacted with PNA in various degrees. Epithelial cells of the secondary lamellae had Con A and PNA positive reaction. These results indicate that glycoconjugate distribution may show interspecific variations, suggesting that the high heterogeneity of naturally occurring glycoconjugates in the epithelial cells of Oscar fish gills might be attributed to the various functional roles of glycoconjugates.

Shockwaves evolving on nanosecond timescales around individual micro-discharge filaments in deionised water

In this study, we present an analysis of the pressure fields developing around nanosecond discharges produced in deionised water by positive high-voltage pulses (+130 and +170 kV) with a fast rise time on a tungsten anode pin. Shockwaves and their associated pressure characteristics were investigated by laser interferometry with a very high spatial resolution of 0.8 μm utilising the concept of a picosecond Mach–Zehnder interferometer based on a Nd:YAG laser (532 nm, 30 ps). Shifts of the fringes in interference patterns due to variations in the refractive index of liquid water produced in the vicinity of the tungsten anode were projected by the interferometer and analysed as a function of the pressure. High spatial resolution combined with the picosecond laser pulse allowed for the examination of frozen interferometric characteristics of cylindrical shockwaves. Consequently, unique results characterising the shockwaves developing around individual discharge filaments were obtained. For easier comparison, the shockwave pressures were normalised to a radius of 0.4 μm, which was found as the most probable maximum of initial radius of primary dark filament. At this radius, the most probable shock pressure was 1.5 GPa, whereas the highest obtained shock pressure reached 11 GPa. We showed that the modified Gaussian distribution fits the obtained results well. Finally, we observed that most of those extraordinary strong shock-fronts were associated with the dark filaments containing strong residual plasma-induced emission. This observation likely provides an indirect evidence of the electrostriction-assisted discharge onset mechanism.

New roles for desmin in the maintenance of muscle homeostasis.

Desmin is the primary intermediate filament (IF) of cardiac, skeletal, and smooth muscle. By linking the contractile myofibrils to the sarcolemma and cellular organelles, desmin IF contributes to muscle structural and cellular integrity, force transmission, and mitochondrial homeostasis. Mutations in desmin cause myofibril misalignment, mitochondrial dysfunction, and impaired mechanical integrity leading to cardiac and skeletal myopathies in humans, often characterized by the accumulation of protein aggregates. Recent evidence indicates that desmin filaments also regulate proteostasis and cell size. In skeletal muscle, changes in desmin filament dynamics can facilitate catabolic events as an adaptive response to a changing environment. In addition, post-translational modifications of desmin and its misfolding in the heart have emerged as key determinants of homeostasis and disease. In this review, we provide an overview of the structural and cellular roles of desmin and propose new models for its novel functions in preserving the homeostasis of striated muscles.

Bioresorbable Primary Battery Anodes Built on Core-Double-Shell Zinc Microparticle Networks.

Bioresorbable implantable electronics require power sources that are also bioresorbable with controllable electrical output and lifetime. In this paper, we report a bioresorbable zinc primary battery anode filament based on a zinc microparticle (MP) network coated with chitosan and Al2O3 double shells. When discharged in 0.9% NaCl saline, a Zn MP filament with a 0.17 × 2 mm2 cross-sectional area exhibited a stable voltage output of 0.55 V at a current of 0.01 mA. Covered by chitosan and Al2O3 double shells, the zinc MP filament exhibited a directional dissolution behavior with a tunable lifetime approximately linear to its length. A stable 200 h discharging time was achieved with a 15 mm Zn MP filament. The maximum output power was found to be 12 μW at 0.03 mA for one filament. The linearity relationship between the current output and the filament cross-sectional area suggested a facile strategy to raise the power output at constant discharging voltage. The filaments could also be connected in series and in parallel to boost its overall voltage and current output, demonstrating their excellent integration capability. This work presents a promising pathway toward bioresorbable transient batteries with controllable lifetime and power output, demonstrating a great potential for powering transient implantable biomedical devices.

Description of a new species of myxobolid parasite, Henneguya pindaibensis n. sp. (Cnidaria: Myxosporea), infecting the gills of Boulengerella cuvieri (Spix and Agassiz, 1829) from Brazil.

Myxozoans are microscopic cnidarians that mainly parasitize fishes. The present study aimed to describe a new myxozoan parasite from the gills of Boulengerella cuvieri (Spix and Agassiz, 1829) by morphological and molecular analysis. The fish was collected in 2019 at the Pindaíba River, municipality of Cocalinho, Mato Grosso State, Brazil. Whitish and circular plasmodia were found in the primary gill filaments, occupying an intralamellar position, with an average of 0.5mm in diameter. Henneguya Thélohan, 1892 myxospores found inside the plasmodia were elongated and ellipsoidal, consisting of two long and elliptical shell valves with two long, tapering caudal appendages. Morphometric measurements revealed a total spore length of 36.1±2.0μm; spore body length of 12.8±0.5μm; spore width of 4.9±0.3μm; tail length of 23.3±1.6μm; capsule length of 7.2±0.4μm; capsule width of 1.5±0.2μm; and 10 coils in the polar filament. Phylogenetic analysis showed that the isolates from this study were grouped into the main-clade of freshwater fishes, within a group of species parasitizing fishes from Brazil. Intergenotypic difference ranged from 23%-25.9% compared with other Brazilian myxozoan isolates. Using molecular and morphological characterization, this parasite was identified as a new species of the genus Henneguya.

Disentangling dark and luminous phases of nanosecond discharges developing in liquid water

There is no clear experimental evidence of the underlying microscopic physical mechanisms of micro-discharges directly produced in liquids. In this study, we examine shadowgraph images and plasma-induced emission (PIE) to decouple simultaneously developing dark and luminous phases of micro-discharges with nanosecond durations in liquid water. We apply diagnostics with extremely high temporal (down to 30 ps) and spatial (down to 1 μm) resolutions to capture tiny bush-like dark filaments that expand from the anode tip together with the formation of luminous tree-like structures. For the first time, we disentangle two closely coupled dark and luminous phases of the discharge events and determine their onsets accurately with respect to the driving high-voltage (HV) pulse. The dark filaments start appearing within ∼3–4 ns after the onset of the HV pulse, and subsequently expand at a constant velocity of ∼1 × 105–2 × 105 m s−1, depending on the HV amplitude and anode curvature. A systematic analysis of the PIE waveforms using the associated shadowgraph images reveals that the onset of the luminous discharge phase is delayed by ∼600–800 ps with respect to the onset of the initial dark filament structures. Considering the constant propagation velocity of dark filaments, the luminous phase starts to develop when the extension of regions with a perturbed refractive index (i.e., perturbed density) reaches several tens of micrometres. An analysis of PIE tracks within the captured shadowgraph images confirms that luminous filaments develop only in regions affected by primary dark filaments and their attachment to the anode surface coincides with points of initial onset of the first dark filaments. Furthermore, the emission intensity produced during the luminous phase originates from the luminous filaments developing in the bulk liquid. Our study provides an important insight into the dynamics of different phases of micro-discharges in de-ionised water.

Steady-state stimulated Raman generation and filamentation using complex vector vortex beams.

Stimulated Raman scattering and laser filamentation produced using nanosecond pulsed complex vector vortex beams (CVVB) are investigated in a 20 cm long methanol cell. The CVVB is generated using q-plates and is tested at orbital angular momentum (L) values of 1, 2, 3, and 4 and circular, radial, and azimuthal polarizations. The results illustrate that the stability and intensity of the generated stimulated Raman has dependence on input polarization and L value. During filamentation, the beam is also shown to break up into multiple primary filaments and that there is a reduction in small-scale filamentation when using CVVBs.

Lymphoid Tissue in Teleost Gills: Variations on a Theme.

In bony fish, the gill filaments are essential for gas exchanges, but also are vulnerable to infection by water-borne microorganisms. Omnipresent across fish, gill-associated lymphoid tissues (GIALT) regulate interactions with local microbiota and halt infection by pathogens. A special GIALT structure has recently been found in Salmonids, the interbranchial lymphoid tissue (ILT). However, the structural variation of GIALT across bony fish remains largely unknown. Here, we show how this critical zone of interaction evolved across fishes. By labeling a conserved T-cell epitope on tissue sections, we find that several basal groups of teleosts possess typical ILT, while modern teleosts have lymphoepithelium of different shape and size at the base of primary gill filaments. Within Cypriniformes, neither body size variation between two related species, zebrafish and common carp, nor morphotype variation, did have a drastic effect on the structure of ILT. Thereby this study is the first to describe the presence of ILT in zebrafish. The ILT variability across fish orders seems to represent different evolutionary solutions to balancing trade-offs between multiple adaptations of jaws and pharyngeal region, and immune responses. Our data point to a wide structural variation in gill immunity between basal groups and modern teleosts.