Swim Bladder Research Articles

Ecotoxicological assessment of Cu-rich acid mine drainage of Sulitjelma mine using zebrafish larvae as an animal model

Acid mine drainage (AMD) is widely acknowledged as a substantial threat to the biodiversity of aquatic ecosystems. The present study aimed to study the toxicological effects of Cu-rich AMD from the Sulitjelma mine in zebrafish larvae. The AMD from this mine was found to contain elevated levels of dissolved metals including Mg (46.7 mg/L), Al (20.2 mg/L), Cu (18.3 mg/L), Fe (19.8 mg/L) and Zn (10.6 mg/L). To investigate the toxicological effects, the study commenced by exposing zebrafish embryos to various concentrations of AMD (ranging from 0.75% to 9%) to determine the median lethal concentration (LC50). Results showed that 96 h LC50 for zebrafish larvae following AMD exposure was 2.86% (95% CI: 2.32–3.52%). Based on acute toxicity results, zebrafish embryos (<2 hpf) were exposed to 0.1% AMD (Cu: 21.7 µg/L) and 0.45% AMD (Cu: 85.7 µg/L) for 96 h to assess development, swimming behaviour, heart rate, respiration and transcriptional responses at 116 hpf. Light microscopy results showed that both 0.1% and 0.45% AMD reduced the body length, eye size and swim bladder area of zebrafish larvae and caused phenotypic abnormalities. Swimming behaviour results showed that 0.45% AMD significantly decreased the locomotion of zebrafish larvae. Heart rate was not affected by AMD exposure. Furthermore, exposure caused a significant increase in oxygen consumption indicating vascular stress in developing larvae. Taken altogether, the study shows that even heavily diluted AMD with environmentally relevant levels of Cu caused toxicity in zebrafish larvae.

Tannic acid adsorption properties of cellulose nanocrystalline/fish swim bladder gelatin composite sponge

Foods and beverages with excessive tannins acid (TA) content taste astringent and bitter. The overconsumption of TA could result in nutritional and digestive problems. In this study, the cellulose nanocrystals (CNC)/fish swim bladder gelatin (FG) composite sponge was prepared with glutaraldehyde as a crosslinking agent. The TA adsorption performance of the sponge was discussed. The freeze-dried CNC/FG composite sponge had a porous network structure. CNC was combined into the FG matrix as a reinforcing phase. The mechanical strength, thermal stability, and swelling properties of the composite sponge were improved with the addition of an appropriate amount of CNC. Although CNC decreased the porosity of composite sponge, the increase in active adsorption sites resulted in an overall positive effect on its TA adsorption properties. Under the optimal adsorption conditions, the TA removal rate of 1.0 % CNC composites reached 80.4 %. Furthermore, the sponge retained a TA removal rate of 54 % after five cycles of adsorption and desorption using 50 % ethanol. The results demonstrated that CNC/FG composite sponge has application potential in the field of adsorption materials for TA.

Effect of photoperiod regime on the growth performance, survival, swim bladder inflation and vertebral anomalies of pikeperch (Sander lucioperca) larvae in recirculating aquaculture systems (RAS)

ABSTRACT The effect of photoperiod on the growth performance, survival rate, swim bladder inflation (SBI) and presence of vertebral anomalies was evaluated in pikeperch larvae reared under intensive production in a recirculating system (RAS). Three different photoperiods were tested from 1 to 30 days post hatch, 12:12 LD, 16:8 LD and 24:0 LD. Larvae were stocked with an initial density of 100 larvae per liter, light intensity of 100 lx and 16.0°C water temperature. The SGR among treatments ranged between 11.17 and 12.04% day−1. The highest survival rate (56.7 ± 2.4%) was found in 24:0 LD with a negative effect on the number of larvae with SBI. The highest presence of vertebral anomalies at 30 dph was found in 24:0 LD (40.8 ± 8.2%) compared to 12:12 LD (2.5 ± 1.4%) and 16:8 LD (1.7 ± 1.6%). These results suggest that constant light compromises culture of pikeperch larvae in RAS. A 16:8 LD photoperiod seems suitable for the growth performance, SBI and low vertebral anomalies at this life stage.

Comparative physiological and immunological assessment of carp crosses

The main purpose of hybridization in the aquaculture industry is improving the productivity of hybrids compared to their parents in specific environmental conditions. The physiological state and resistance are judged by blood parameters, which are sensitive and informative indicators of the state of the body’s defense power and allow timely detection their changes under the influence of abiotic and biotic environmental factors. The article presents the results of studying of the productive and physiological properties of two-year-old carp crosses: interbreed hybrids of the first generation (F1). Shown, that the driveability index of the new threebreed carp cross is significantly lower than that of the “Surskiy Malokostny” and “Petrovskiy” crosses, which characterizes its high commercial qualities. The new three-breed cross has a lower swim bladder index: the lengths of the anterior and posterior chambers are almost equal. The number of vertebrae is less, compared to others. However, in the caudal region the number of vertebrae is close to that of the “Sursky Malokostny” cross and greater than that of the “Petrovsky”. In terms of size and weight indicators, the two-year-olds of the new three-breed carp cross exceeded those of other studied crosses, which indicates significant production potential. All recorded blood parameters of the studied fishes were within the limits of the physiological norm. The new three-breed cross is characterized by a high level of nonspecific cellular protection: a large proportion of microphages — segmented neutrophils is noted in the blood leukogram of the new cross. High immune resistance is evidenced by high vitality and a relatively low content of cationic protein in the lysosomes of neutrophils, which is consumed during immune defense when preparing fish for wintering. A comparative assessment of the crosses showed their excellent and productive marketable qualities, survival at different stages of ontogenesis, and good physiological and immunological status.

Electronics-Free Soft Robotic Knee Brace for Dynamic Unloading During Gait for Knee Osteoarthritis: A Proof-of-Concept Study

Abstract We present a novel electronics-free soft robotic knee brace which employs a closed-loop fluidic regenerative (CLFR) system for dynamic unloading in unicompartmental tibiofemoral osteoarthritis (OA). The existing dynamic unloaders are bulky, large, and heavy, and have low compliance likely due to the use of an electrical control box, which is eliminated in the CLFR system. The system consists of a commercial unloading knee brace, a spring-loaded bellow inserted under the heel inside a shoe, a soft-fluidic actuator (bladder), and tubing for fluid transfer. The novelty lies in the fact that the user's body weight (self-powered) compresses the bellow to provide energy to inflate the air bladder placed at the knee. As a result, the yielded pressure unloads the undesirable forces due to knee OA during the stance phase of gait while strategically applying no forces during the swing phase. The knee bladder contact pressure/force, the system response time, and the durability were evaluated via contact pressure measurements for six systems with varying bellow volumes and either pneumatic or hydraulic configurations. All systems produced safe pressure outputs for human skin within a tested bodyweight range of 60–90 kg. Pneumatic and hydraulic systems achieved 250 ms and 400 ms pressurization response times, respectively. During cyclic loading, pneumatic and hydraulic systems demonstrated less than 1% and ∼10% pressure loss, respectively. Overall, the CLFR system created a promising electronics-free solution for dynamically unloading the knee during gait, indicating a potential new paradigm for knee braces.

Application of a hydraulic gas bladder suppressor for pressure ripple reduction in gear pumps

Gear pumps are widely employed in hydraulic circuit but they carry the major drawback represented by the pulsating flow they produce. To improve the capability of the pump to produce a clean and smooth flow rate, many methods have been investigated over time: from the optimization of pump features itself to the introduction of additional systems on the pump delivery side. One system that has demonstrated to be particularly effective is the in-line bladder hydraulic pulsation suppressor, which is part of the passive systems category. This device consists of a bladder gas accumulator with a particularly clever geometry and is the focus of many studies. The study illustrated in this paper has the aim of proposing a lumped parameter model capable of predicting the hydraulic suppressor ripple reduction performance. To test the actual performance of the suppressor and validate the lumped parameter model, an experimental study was conducted, which demonstrated the good effectiveness of device, while a good agreement between modeling results and experimental data was obtained.

Depth and temperature preferences of meagre, Argyrosomus regius, as revealed by satellite telemetry.

Argyrosomus regius (commonly referred to as meagre), is one of Europe's largest coastal bony fish species and supports important recreational and commercial fisheries in the Atlantic and Mediterranean coasts. Demand for this species, and more recently for their swim bladders, has led to regional population declines and growing importance as an aquaculture species. Despite intense research in captivity, little is known about the spatial ecology of A. regius's wild population, including basic information such as vertical migrations and depth/temperature preferences. Previous research based on indirect data suggests a seasonal habitat shift from shallow to deeper waters, but this has never been validated through direct high-resolution movement data. In this study, we tagged 13 adult A. regius with pop-up satellite archival tags in the South of Portugal, which successfully returned data from 11 individuals including high-resolution data from six recovered tags (mean, range: 167 days, 28-301 days). We found that adults of this population spend 95.2% of their time between 5 and 75 m depth (mean ± SD, 30.9m ± 18.3m) and do not venture beyond 125 m. Across seasons, A. regius move across water temperatures between 13.3 and 24.8°C with a preferred thermal range between 14 and 18°C where they spent 75.4% of their time. The inferential modelling using this electronic data validated previous hypotheses by showing significant differences between a shallower and warmer summer habitat vs. a deeper and cooler winter habitat. Visual investigation of the diel effects on depth preferences suggests subtle changes in depth use between day and night during the warmer months of the year. We speculate that these patterns are in response to the species' behavioural ecology and physiology, reflecting the seasonal changes in water stratification and presence of prey, as well as on the species reproduction, which results in summer spawning aggregations in shallower areas.

Effects of Sublethal Concentrations of the Herbicide, Glyphosate, on Embryonic Development of the Indian Major Carp, Labeo rohita

Aquaculture is one of the fastest growing sectors worldwide. Currently, 50% of global fish consumption is provided by aquaculture. In India, the major cultivated fishes are Labeo catla, Labeo rohita, Cirrhinus mrigala, Hypophthalmichthys molitrix, Ctenopharyngodon idella, and Cyprinus carpio. Among these, L. rohita is a widely consumed fish. We aimed to study the effect of one of the most widely used herbicides, glyphosate, on the embryonic development of L. rohita. The 96 h LC50 of glyphosate for L. rohita embryos was found to be 20.89 mgL−1. The embryos were exposed to 1/10th, 1/5th,, and 1/3rd concentrations of LC50 for 96 h. The observed deformities included abdominal curvature, kink formation in the tail, yolk sac edema, pericardial edema, and improperly flattened swim bladder. Besides, we could observe a reduction in pigmentation at 96 h and a decrease in heart rate at 24, 48, 72, and 96 h. All these deformities led to the mortality of embryos. This study indicated that the herbicide (glyphosate) can adversely affect the natural population of the Indian major carp, L. rohita.

Role of material properties in acoustical target strength: Insights from two species lacking a swimbladder

Acoustic target strength (TS) is a key parameter for species identification and stock assessment in fisheries. The TS of fish is influenced by the contrast in acoustic impedance between their tissues and the surrounding water. While the swimbladder is responsible for most of the backscatter in fish with gas-filled swim bladders, the backscatter in bladderless fish is a combination of that of fish tissues. The aim of this paper is to explain the marked differences in acoustic properties reported between skipjack tuna and Atlantic mackerel, two important pelagic fish species that lack a swimbladder. The study measures the acoustic properties (density and sound speed) of their flesh and backbone. These measurements are then used to simulate acoustic backscattering using a numerical model based on the Method of Fundamental Solutions, covering a range of frequencies and fish lengths relevant to fisheries acoustics. The numerical estimation of the TS shows that the differences in the material properties of the tissues predict the reported differences in the reduced target strength of more than 10 dB greater for skipjack than for mackerel at 38 kHz and 120 kHz. The study contributes to the understanding of the complex acoustic field backscattered by bladderless fish species and provides insights into the role of fish tissue material properties in the interpretation of acoustic response differences between species.

Capture of wild juveniles, growth and spawning of the southwestern Atlantic wreckfish (Polyprion americanus) in Argentina

Wreckfish (Polyprion americanus) is a marine fish of great interest as a new aquaculture species due to its easy adaptation to farming conditions, rapid growth and market price. In the Southwestern Atlantic Ocean, the species forms a genetic stock different from that of the Northern Hemisphere and also to populations of the South Pacific. This study presents the research conducted in Argentina from 2011 to 2020 on the development of a wreckfish broodstock from juvenile specimens. Wreckfish (n = 21) were caught with fishing rods at depth between 18 and 75 m depth, off the coast of Buenos Aires Province, Argentina (37°30′S - 39°00′S). All fish suffered barotrauma, but specimens captured at a depth < 45 m and whose swim bladders were deflated by puncture had a survival rate > 90%. Juvenile wreckfish (n = 12) with an initial body weight of 2–3 kg were kept in a recirculating aquaculture system (RAS) and fed local fish for 36 months. During this on-growing stage, a natural photoperiod regime with reduced light intensity was accompanied by seasonal variations in the RAS's thermal regime (14–19 °C). From then on, a maturity and reproductive protocol was implemented, where the temperature was lowered (12–17 °C) and the diet was complemented with a formulated semi-moist feed. Juvenile wreckfish grew fast, gaining about 2.5 kg in 11 months with a specific growth rate (SGRBW) of 0.2% day−1 and reaching 10–12 kg in 36 months. There was no significant difference in growth performance between sex groups during the on-growing stage. However, from months 36 to 57, the SGRBW of females (0.058 ± 0.008% day−1) was significantly higher than males (0.035 ± 0.005% day−1). After 67 months in captivity, the first natural spawning was achieved in a communal tank with a sex ratio 4 females: 6 males. Two consecutive spawning seasons were analysed, which showed a large daily variation in total number of eggs, percentage of floating eggs (potentially viable eggs) and spawning intervals. A marked improvement in spawning performance was observed from one season to the next. In the first season, a total production of 5.21 million eggs was reached, of which only about 2.7% were floating, while in the second season the values increased to 13.23 million eggs and 32.6%, respectively. We have successfully developed a broodstock of wreckfish capable of achieving natural spawning. Further research is needed to obtain reliable spawning and large production of high-quality eggs.

Boyle’s Law ignores dynamic processes in governing barotrauma in fish

The expansion and potential rupture of the swim bladder due to rapid decompression, a major cause of barotrauma injury in fish that pass through turbines and pumps, is generally assumed to be governed by Boyle’s Law. In this study, two swim bladder expansion models are presented and tested in silico. One based on the quasi-static Boyle’s Law, and a Modified Rayleigh Plesset Model (MRPM), which includes both inertial and pressure functions and was parametrised to be representative of a fish swim bladder. The two models were tested using a range of: (1) simulated and (2) empirically derived pressure profiles. Our results highlight a range of conditions where the Boyle’s Law model (BLM) is inappropriate for predicting swim bladder size in response to pressure change and that these conditions occur in situ, indicating that this is an applied and not just theoretical issue. Specifically, these conditions include any one, or any combination, of the following factors: (1) when rate of pressure change is anything but very slow compared to the resonant frequency of the swim bladder; (2) when the nadir pressure is near or at absolute zero; and (3) when a fish experiences liquid tensions (i.e. negative absolute pressures). Under each of these conditions, the MRPM is more appropriate tool for predicting swim bladder size in response to pressure change and hence it is a better model for quantifying barotrauma in fish.

Comparative Mitogenomics Reveals Cryptic Species in Sillago ingenuua McKay, 1985 (Perciformes: Sillaginidae).

It is unreliable to identify marine fishes only by external morphological features. Species misidentification brings great challenges to fishery research, resource monitoring and ecomanagement. Sillago ingenuua is an important part of commercial marine fishes, and in which, the morphological differences between different groups are not obvious. Here, we compared different geographical groups of S. ingenuua which were collected from Xiamen, Dongshan, Keelung, Songkhla and Java. The results showed that all samples of S. ingenuua were similar in external morphological characteristics and the shape of the swim bladder, but there were two distinctive lineages which were flagged as cryptic species based on DNA barcoding. The comparative mitogenomic results showed that S. ingenuua A and S. ingenuua B were identical in structural organization and gene arrangement. Their nucleotide composition and codon usage were also similar. A phylogenetic analysis was performed based on 13 concatenated PCGs from eight Sillago species. The results showed that the genetic distance between S. ingenuua A and S. ingenuua B was large (D = 0.069), and this genetic distance was large enough to reveal that S. ingenuua A and S. ingenuua B might be different species.

Sound production biomechanics in three-spined toadfish and potential functional consequences of swim bladder morphology in the Batrachoididaea).

The relationship between sound complexity and the underlying morphology and physiology of the vocal organ anatomy is a fundamental component in the evolution of acoustic communication, particularly for fishes. Among vertebrates, the mammalian larynx and avian syrinx are the best-studied vocal organs, and their ability to produce complex vocalizations has been modeled. The range and complexity of the sounds in mammalian lineages have been attributed, in part, to the bilateral nature of the vocal anatomy. Similarly, we hypothesize that the bipartite swim bladder of some species of toadfish (family Batrachoididae) is responsible for complex nonlinear characters of the multiple call types that they can produce, supported by nerve transection experiments. Here, we develop a low-dimensional coupled-oscillator model of the mechanics underlying sound production by the two halves of the swim bladder of the three-spined toadfish, Batrachomoeus trispinosus. Our model was able to replicate the nonlinear structure of both courtship and agonistic sounds. The results provide essential support for the hypothesis that fishes and tetrapods have converged in an evolutionary innovation for complex acoustic signaling, namely, a relatively simple bipartite mechanism dependent on sonic muscles contracting around a gas filled structure.

Fish hearing revealed: Do we understand hearing in critical fishes and marine tetrapods.

Hearing evolved in lampreys with a frequency range of 50-200 Hz. This hearing range is comparable to that of elasmobranchs, most non-teleosts, and lungfish. Elasmobranchs most likely use the saccule and the papilla neglecta (PN) for hearing. In non-teleosts and teleosts, lungfish, and certain tetrapods the saccule is the likely sensor for sound reception while the lagena and the PN are important for gravistatic sensing. Coelacanth and most tetrapods have a basilar papilla (BP) for hearing. In coelacanth and tetrapods, the hair cells of the BP are in contact with a basilar and a tectorial membrane. These membranes transmit mechanical vibrations. A cochlear aqueduct (CA) provides a connection between the cerebrospinal fluid that has a sodium rich space in coelacanth and tetrapods while the potassium rich endolymph is known in vertebrates. A unique feature is known in basic sarcopterygians, the intracranial joint, that never developed in actinopterygians and has been lost in lungfish and tetrapods. The BP in coelacanths is thought to generate pressure with the intracranial joint that will be transmitted to the CA. Lungs or a swim bladder are not forming in Chondrichthyes, structures that have a major impact on hearing in teleosts and tetrapods.

Physicochemical properties, biological activities, and peptidome profile of grass carp swim bladder collagen hydrolysates

This study investigated the physicochemical properties and biological activities of hydrolysates derived from grass carp swim bladder collagen through enzymatic hydrolysis using Papain, Alcalase, Flavourzyme, and Neutrase. The results indicated that the select of protease significantly influences the degree of hydrolysis (DH), molecular weight distribution (MW), trichloroacetic acid-nitrogen solubility index (TCA-NSI), structure, and bioactivities of the hydrolysates. The hydrolysate of Alcalase (HA) exhibited the highest DH, TCA-NSI, Fe2+ chelating activity, 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity, and angiotensin-converting enzyme (ACE) inhibitory activity. Pearson's correlation and principal component analysis (PCA) revealed strong interrelationships among the DH, TCA-NSI, β-sheet content, Fe2+ chelating activity, ACE inhibitory activity, and short peptide content within the hydrolysates (|r| > 0.80, P < 0.05). A total of 524 peptides were identified from HA, and 20 novel peptides with no toxicity, no allergenicity, and potential bioactivity were discovered by in silico strategy. Molecular docking analysis revealed that hydrophobic interactions and hydrogen bonds were the primary interaction forces between the peptides with free radicals and ACE. These findings provide a foundation for the high-value utilization of grass carp swim bladder hydrolysates as bioactive peptides in the food industry, enabling the sustainable utilization of freshwater swim bladder by-products.

Evidence of Atlantic midshipman (Porichthys plectrodon) vocalizations from an unmanned surface vehicle in the U.S. South Atlantica).

An unmanned surface vehicle (USV; Wave Glider) was deployed to study the coastal soundscape in shallow (less than 30 m) coastal waters off the coast of Cape Canaveral, FL, in July 2020 and January 2022. These surveys documented temporal and seasonal trends in biological sounds across a variety of habitats within an 812-km2 survey area, including sand shoals, sand-mud plains, and natural hardbottom. Among a broader diversity of identifiable and unidentifiable fish choruses recorded during the survey, a distinct and previously unidentified fish chorus was recorded; corroborating evidence suggests it and other sounds with similar spectral properties may be produced by Atlantic midshipman. Putative Atlantic midshipman sounds included an agnostic grunt and a seasonal chorus of persistent hums that peaked 3 h after sunset in the summer survey. While Atlantic midshipman have been demonstrated to have well-developed sonic muscles on their swim bladder, their acoustic behavior has not been previously described. Our use of a mobile passive acoustic platform combined with bottom sampling of fish communities highlights an important opportunity to identify previously undocumented biological sound sources in coastal habitats.

Icariin induces developmental toxicity via thyroid hormone disruption in zebrafish larvae

Icariin (ICA) is a natural flavonoid isolated from the traditional Chinese medicinal herb, Epimedium brevicornu Maxim. Although previous studies have reported that ICA exhibits various pharmacological activities, little is known about its toxicology. Herein, zebrafish embryos were exposed to ICA at 0, 2.5, 10, and 40 μM. In developmental analysis, reduced hatching rates, decreased body length, and abnormal swim bladder were found after treatment with 10 and 40 μM ICA. In addition, the ability of locomotor behavior was impaired by ICA. Two important thyroid hormones (THs), triiodothyronine (T3) and thyroxine (T4), were tested. The exposure resulted in a remarkable alteration of T4 level and a significant decrease of the T3/T4 ratio in the 40 μM, indicating thyroid endocrine disruption. Furthermore, gene transcription analysis showed that genes involved in thyroid development (nkx2.1) and THs synthesis (tg) were up-regulated after ICA exposure. Significant down-regulation of iodothyronine deiodinase (dio1) was also observed in the 10 and 40 μM groups compared to the control. Taken together, our study first demonstrated that ICA caused developmental toxicity possibly through disrupting thyroid development and hormone synthesis. These results show that it is necessary to perform risk assessments of ICA in clinical practice.

Diving into dual functionality: Swim bladder muscles in lionfish for buoyancy and sonic capabilities.

Although the primary function of the swim bladder is buoyancy, it is also involved in hearing, and it can be associated with sonic muscles for voluntary sound production. The use of the swim bladder and associated muscles in sound production could be an exaptation since this is not its first function. We however lack models showing that the same muscles can be used in both movement and sound production. In this study, we investigate the functions of the muscles associated with the swim bladder in different Pteroinae (lionfish) species. Our results indicate that Pterois volitans, P. radiata and Dendrochirus zebra are able to produce long low-frequency hums when disturbed. The deliberate movements of the fin spines during sound production suggest that these sounds may serve as aposematic signals. In P. volitans and P. radiata, hums can be punctuated by intermittent louder pulses called knocks. Analysis of sonic features, morphology, electromyography and histology strongly suggest that these sounds are most likely produced by muscles closely associated with the swim bladder. These muscles originate from the neurocranium and insert on the posterior part of the swim bladder. Additionally, cineradiography supports the hypothesis that these same muscles are involved in altering the swim bladder's length and angle, thereby influencing the pitch of the fish body and participating in manoeuvring and locomotion movements. Fast contraction of the muscle should be related to sound production whereas sustained contractions allows modifications in swim bladder shape and body pitch.

Do zebrafish become blind or is it too much red dye in water? Distinguishing the embryo-larval development and physiology effects of DR 60, 73, and 78

Some dyes currently used by the textile, pharmaceutical, food, cosmetic, and photographic industries have been shown to be toxic and/or mutagenic to aquatic life. Most of these dyes resist degradation processes available for treating wastewater, and these processes might generate even more toxic by-products. Despite the large number of available dyes and the large quantity of dyes released into the environment, studies on their toxicity are still scarce. We evaluated and compared the effects in the animal model Danio rerio (zebrafish) of environmentally relevant concentrations of Disperse Red 60 (DR 60), 73 (DR 73), and 78 (DR 78) using the fish embryo acute toxicity (FET) test, morphometric analysis, immunofluorescence imaging, and behavioral parameters. DR 60 caused ocular modifications, while the DR 73 caused non-inflation of the swim bladder (NISB), pericardial edema (PE), scoliosis (S) and abnormal yolk sac (AYS) from at 0.125 mg/L. In behavioral tests, all the dyes induced changes in velocity and time spent swimming of exposed larvae. However, these alterations in behavior seem to be caused by different factors dependent on the dye and its concentration. Nevertheless, behavior seems to add valuable information concerning the hazards analysis of dyes, since it reveals to be the most sensitive group of parameters tested in the current study. In conclusion, of the behavioral and developmental alterations caused by these dyes should be interpreted as an alert for greater attention when registering new dyes and releasing them into the environment. In the particular case of DR 60 the possibility that directly affects the eye of larvae is of great environmental concern, but also from the human health perspective.

Mevinphos induces developmental defects via inflammation, apoptosis, and altered MAPK and Akt signaling pathways in zebrafish

Mevinphos, an organophosphate insecticide, is widely used to control pests and enhance crop yield. Because of its high solubility, it can easily flow into water and threaten the aquatic environment, and it is known to be hazardous to non-target organisms. However, little is known about its developmental toxicity and the underlying toxic mechanisms. In this study, we utilized zebrafish, which is frequently used for toxicological research to estimate the toxicity in other aquatic organisms or vertebrates including humans, to elucidate the developmental defects induced by mevinphos. Here, we observed that mevinphos induced various phenotypical abnormalities, such as diminished eyes and head sizes, shortened body length, loss of swim bladder, and increased pericardiac edema. Also, exposure to mevinphos triggered inflammation, apoptosis, and DNA fragmentation in zebrafish larvae. In addition, MAPK and Akt signaling pathways, which control apoptosis, inflammation, and proper development of various organs, were also altered by the treatment of mevinphos. Furthermore, these factors induced various organ defects which were confirmed by various transgenic models. We identified neuronal toxicity through transgenic olig2:dsRed zebrafish, cardiovascular toxicity through transgenic fli1:eGFP zebrafish, and hepatotoxicity and pancreatic toxicity through transgenic lfabp:dsRed;elastase:GFP zebrafish. Overall, our results elucidated the developmental toxicities of mevinphos in zebrafish and provided the parameters for the assessment of toxicities in aquatic environments.