Fish Larvae Research Articles

Zygotic Exposure to Venlafaxine Disrupts the Circadian Locomotor Activity Behaviour in Zebrafish Larvae.

The antidepressant venlafaxine, a selective serotonin and norepinephrine reuptake inhibitor, is commonly prescribed to treat major depressive disorder and is found at high concentrations in the aquatic environment. Concerns have been raised related to the health of aquatic organisms in response to this nontargeted pharmaceutical exposure. For instance, we previously demonstrated that exposure to venlafaxine perturbs neurodevelopment, leading to behavioural alterations in zebrafish (Danio rerio). We also observed disruption in serotonin expression in the pineal and raphe, regions critical in regulating circadian rhythms, leading us to hypothesize that zygotic exposure to venlafaxine disrupts the circadian locomotor rhythm in larval zebrafish. To test this, we microinjected zebrafish embryos with venlafaxine (1 or 10 ng) and recorded the locomotor activity in 5-day-old larvae over a 24-h period. Venlafaxine deposition reduced larval locomotor activity during the light phase, but not during the dark phase of the diurnal cycle. The melatonin levels were higher in the dark compared to during the light photoperiod and this was not affected by embryonic venlafaxine deposition. Venlafaxine exposure also did not affect the transcript abundance of clock genes, including clock1a, bmal2, cry1aand per2, which showed a clear day/night rhythmicity. A notable finding was that exposure to luzindole, a melatonin receptor antagonist, decreased the locomotor activity in the control group in light, whereas the activity was higher in larvae raised from the venlafaxine-deposited embryos. Overall, zygotic exposure to venlafaxine disrupts the locomotor activity of larval zebrafish fish during the day, demonstrating the capacity of antidepressants to disrupt the circadian rhythms in behaviour. Our results suggest that disruption in melatonin signalling may be playing a role in the venlafaxine impact on circadian behaviour, but further investigation is required to elucidate the possible mechanisms in larval zebrafish.

Does transcriptome of freshly hatched fish larvae describe past or predict future developmental trajectory?

Transcriptomic analysis of freshly hatched fish larvae offers insights into phenotype development, yet it remains uncertain whether it reflects parental influence or predicts individual growth. This research scrutinizes the transcriptome of 16 Eurasian perch (Perca fluviatilis) larval families (at mouth opening stage, coinciding in this species with hatching) alongside pre- and post-hatching zootechnical traits. Despite consistent fertilization rates, significant variations in embryonic development and larval performance highlight diverse phenotypes studied. It enabled us to bring our attention to the fact that transcriptome of larvae at mouth opening stage can serve as a window into both the parental contributions and the future performance of the larvae. Our analysis shed light on ribosome biogenesis, neurogenesis, and the cell cycle, as important processes shaping early larval performance. Additionally, we propose a set of predictive, validated gene markers associated with further larval performance and key aquaculture traits, such as selenoo (associated with cannibalism), trim16 (fulton's condition factor), slc15a1 (specific growth factor), and cipc (final weight). This study delves into the descriptive and predictive nature of the transcriptomic portrait of newly hatched larvae, paving the way to comprehend the intricate developmental pathways from fertilization towards juvenile stage.

BENEFITS OF PHOSPHOLIPIDS IN AQUAFEED DEVELOPMENT: A REVIEW

Fish oil (FO) is the main source of lipids in aquafeed, but its use has become very unsustainable due to over-exploitation, scarcity and high cost. Plant oil has been proposed as an alternative to FO, but they are less digestible and not rich in fatty acids. In addition, larval and juvenile fish are unable to synthesise sufficient phospholipids (PLs) for their metabolic need. Hence, the necessity to supplement PLs in their diets. This review describes the application and beneficial impact of dietary PLs in aquafeed. PLs are an essential component of aquafeed as they supply energy for metabolic activities and enhance digestion and absorption of other dietary lipids. Plantbased PLs such as soy lecithin serve as an emulsifier that helps lipid catabolism by facilitating enzymatic hydrolysis in the fish’s digestive system, besides improving nutrient absorption, growth and health. Studies on farm animals have confirmed the positive effects of PLs. Although the literature on aquafeed application is limited, to growth and health of farmed fish and crustaceans. The use of PLs in aquaculture is set to increase as both feed producers and farmers seek to maximise production through efficient feed utilisation and ensure sustainability in delivering quality fish to consumers.

Agricultural Pesticide-Induced Physiological Stresses in Freshwater Fishes of Bangladesh

In Bangladesh, most croplands are situated in floodplains, enriched by numerous rivers and extensive freshwater wetlands. These areas also support productive open-water fisheries, crucial for supplying protein, generating income, creating jobs, and boosting the GDP. However, the widespread use of pesticides in these floodplains to protect crops and enhance food production leads to significant environmental issues. Agricultural pesticide residues enter water bodies through runoff, rainwater, drainage, seepage, and spray drift, contaminating natural water bodies and exerting continuous stress on aquatic life, including fish. Previous studies have detected pesticide residues in surface waters, sediments, and fish in Bangladesh, posing a major threat to wetland ecosystems. Research on freshwater fish species in Bangladesh has highlighted toxic effects on fish gonads, such as adhesion, inter-follicular space degeneration, ovigerous lamellae degeneration, necrosis, degenerated perinucleolar oocytes, cytoplasmic retraction in ovaries, and damage to sertoli cells. Additional observed effects include irregularly shaped seminiferous tubules, breakage of seminiferous tubules, and empty lumens in testes. Pesticides also inflict harm on other internal organs of fish, with gill effects like clubbing, reduction of gill filaments, telangiectasia of gill lamellae, hemorrhage, and damage to gill rakers. Kidney and liver damage include necrosis, cellular tissue degradation, acute cellular swelling, and irregular renal corpuscles, along with autolysis, vacuolation, and fatty changes in the liver. Developing embryos and larvae of freshwater fish are particularly vulnerable to the toxic effects of agro-pesticides. Studies reveal acute toxicity during early life stages, evidenced by deformities like edema, notochord deformity, caudal fin damage, yolk sac damage, posterior region damage, tissue fragmentation, black pigmentation on the yolk, body curvature, and lordosis in larvae. Exposed embryos exhibit deformities such as dark brown yolk sacs, notochord deformities, and broken eggshells. Mortality rates of fish embryos and larvae escalate with higher pesticide concentrations in water. Haemato-biochemical parameters serve as crucial indicators of pesticide exposure in fish studies, showing alterations in blood hemoglobin, glucose, RBC, WBC counts, and various erythrocytic abnormalities like twin cells, fusion, echinocyte formation, spindle-shaped, tear-drop, and elongated cells. Nuclear abnormalities include binucleated cells, nuclear buds, nuclear bridges, karyopyknosis, and notched nuclei. Research suggests that even at low concentrations, agro-pesticides disrupt physiological functions and life history traits of fish, adversely impacting the natural productivity and biodiversity of freshwater fish in Bangladesh.

Vitamin Solutions Effects on Reproduction of Broodstock, Growth Performance, and Survival Rate of Pangasius Catfish Fingerlings.

This study evaluates the effect of different diets supplemented with vitamin solutions on Pangasius catfish broodstock reproduction, growth performances, and the survival rates of fish larvae and fingerling. The growth and reproductive performances of breeders fed with different test diets showed significant differences among the six tested diets (p < 0.05). The highest final body weight (FBW), weight gain (WG), daily weight gain (DWG), specific growth rate (SGR) of broodstock, and survival rate of Pangasius fingerlings were found in Treatment 5, which contained 0.6% H-OVN mixed with 12.6% algal oil, and Treatment 3, which contained 0.6% vitamin premix H-OVN. The average gonadosomatic index (GSI), relative fecundity index (RFI), fertilized eggs, hatching rates of eggs, and survival rate of fingerlings was 9.1 ± 2.8 (6.7-12.8%), 133,224 ± 39,090 (104,267-199,512 eggs/kg), 77.9 ± 22.2 (62.2-93.6%), and 45.3 ± 17.4 (22.0-66.3%), respectively. The findings of this study showed that the diet containing 35% CP contents supplemented with 0.6% vitamin premix H-OVN mixed with algal oils showed the highest results in terms of growth, reproductive performance indices, and survival rates of Pangasius catfish fingerlings.

Microscopic photoplethysmography-based evaluation of cardiotoxicity in whitefish larvae induced by acute exposure to cadmium and phenol.

Toxic environmental pollutants pose a health risk for both humans and animals. Accumulation of industrial contaminants in freshwater fish may become a significant threat to biodiversity. Comprehensive monitoring of the impact of environmental stressors on fish functional systems is important and use of non-invasive tools that can detect the presence of these toxicants in vivo is desirable. The blood circulatory system, by virtue of its sensitivity to the external stimuli, could be an informative indicator of chemical exposure. In this study, microscopic photoplethysmography-based approach was used to investigate the cardiac activity in broad whitefish larvae (Coregonus nasus) under acute exposure to cadmium and phenol. We identified contamination-induced abnormalities in the rhythms of the ventricle and atrium. Our results allow introducing additional endpoints to evaluate the cardiac dysfunction in fish larvae and contribute to the non-invasive evaluation of the toxic effects of industrial pollutants on bioaccumulation and aquatic life.

Rapid inference of larval fish recruitment potential from size spectrum models

The ratio of mortality to growth of larval fish provides a metric of a cohort’s “recruitment potential”. Estimating recruitment potential is arduous, requiring growth and mortality to be estimated independently. Here, we propose using the exponent of size spectrum models to indicate recruitment potential from body measurement data alone. This approach has several advantages including (1) reducing data collection times, (2) removing uncertainty in estimates generated from age estimation, and (3) allowing re-analysis of larval fish databases or archived collections. To test the validity of this approach, we conduct simulations comparing estimates of recruitment potential from an abundance spectrum model with other common methods. By varying larval flux rates, growth, mortality, and measurement error, we show the abundance spectrum model is more accurate and precise at smaller sample sizes, and more robust to variance in individual rates and measurement error of ages, but more susceptible to measurement error of size. We highlight that a size-based approach to estimating recruitment potential provides another useful tool for understanding larval survival, reducing resource demands on research compared to traditional methods.

Developing a habitat suitability index with field data and hydraulic models

AbstractLinking habitat availability with hydraulic models integrates river engineering in the ecological field. Field observation for species presence and physical habitat availability mapping is inherently limited due to time and access constraints for field data collection. This study leverages hydraulic modeling to supplement larval fish population monitoring data, effectively expanding mapped physical habitat and allowing for monitoring bias analysis. The inundation extents and character of streamflow from hydraulic modeling were used to refine habitat suitability indices relative to total habitat availability from discrete fish monitoring events. Given the flexibility in hydraulic modeling to simulate a range of flows, the habitat suitability index is then translated to an effective habitat curve according to areal inundation and hydrologic frequency. With this framework, forecasting the impacts of long‐term trends, such as geomorphic or hydrologic change, can be reasonably and quantitatively assessed. This manuscript uses a case study of Rio Grande silvery minnow monitoring at restoration sites where the floodplain has been lowered via earthwork. Comparisons are made for habitat suitability indices developed from field observation data alone and field observation supplemented by hydraulic modeling. Known biases of field sampling data (targeting slow, shallow areas where fish are most often found) were confirmed based on simulated hydraulic conditions across entire restoration sites. In the case of Rio Grande silvery minnow, a heavily studied species, such field monitoring biases are an effective use of resources. However, this framework may be helpful for assessing alternative management approaches and monitoring strategies of species that are less studied.

Inter-annual changes in zooplankton in the Volga delta kultuk zone in summer (low-water period)

The paper presents the results of our studies of inter-annual changes in the structure of summer zooplankton in the kultuk zone of the Volga delta depending on hydrological and meteorological conditions. The study shows the main trends in zooplankton differences in a series of low-water years. It was found that in low-water years in the kultuk zone with low runoff, short floods and weak watering of floodplain territories, zooplankton was characterized by low species richness, reduced average individual mass of crustaceans and the number of Rotifera, but a high proportion of the number of juvenile Copepoda. In the year when the water level decreased before the flood during the period of temperature increase, and then a rapid rise with the inflow of cold waters and the removal of fish larvae, zooplankton was characterized by a minimum species richness and quantitative values of Rotifera, but increased biomass of Cladocera and the Shannon index. In every low-water year, with a stable and relatively high water level before the flood, fish spawning in the kultuk zone, biomass of zooplankton reduced due to Cladocera, and the number of species in the sample. In every mid-water year, the flood had the largest runoff and prolonged, increased flooding of the floodplain, zooplankton was characterized by the maximum total and specific species richness, abundance of Rotifera, total biomass on account of Cladocera, and the individual mass of crustaceans, the Shannon index, but the minimum proportion of juvenile Copepoda.

Seasonal and Spatial Distribution of Zooplankton Communities with Relation to some Physico-Chemical Parameters in the South East Coast of Bangladesh

Seasonal and spatial distribution of zooplankton communities in relation with some physico-chemical parameters in the south eastern coastal waters of Bangladesh was carried out from January 2016 to November 2016. Zooplankton samples were collected from seven different selected stations covering various ecosystems, viz.: Riverine (Bhola, Barishal &amp; Chandpur), Offshore Island water (Sandwip &amp; Hatia) and Nearshore (Cox’s bazar &amp; Naf River) regions. In total 33 genera were recorded during sampling periods and the highest abundance of zooplankton were recorded at Naf River (331.318 ind/m3) and the lowest at Chandpur (22.6414ind/m3) during post-monsoon. In pre-monsoon the highest abundance was recorded at Sandwip (31.49435ind/m3) and the lowest at Bhola (8.239854ind/m3). During monsoon the highest abundance was recorded at Cox’s Bazar (51.64085ind/m3) and the lowest at Barishal (4.389972ind/m3). A total of 24, 22 and 32 individuals (genera) of zooplankton identified during monsoon, pre-monsoon and post-monsoon respectively from all sampling stations. Calanoida, Cyclopoida, Fish larvae, Lucifer and Shrimp Zoea were common in every sampling station. Dictoyptera was the only species found in marine water. The statistical analysis of water quality parameters as temperature, pH, salinity, transparency, DO, TDS and TSS indicated the substantial relationship with seasonal and spatial distribution, diversity and abundance of zooplankton. Diversity index also indicated seasonal and spatial variation of zooplankton communities in the south eastern coastal waters of Bangladesh. The Chittagong Univ. J. B. Sci.,Vol. 10(1 &amp;2):95-119, 2020

Distribution and abundance of ichthyoplankton in natural al artificial reefs in Edremit Bay, Northern Aegean Sea, Türkiye

Edremit Bay is one of the important areas for small–scale fishing in the North Aegean Sea. For this reason, more detailed ichthyoplankton studies should be continued to evaluate the fish stock status of the region, calculate the adult fish biomass, and determine the spawning period, place, and time of fish species. In addition, from 2011 to 2013, artificial reefs were constructed in Edremit Bay. Regular investigation of fish eggs and larvae in the region influenced by the Edremit Bay artificial reef would provide better knowledge of the structure and function of the local ecosystem and provide a basis for monitoring the marine ecosystem in the area. The current research examined the species abundance and distribution of surface plankton samples collected in 2015 and 2016. The evaluation also included the influence of abiotic environmental factors such as temperature, pH, chlorophyll a (chl–a), salinity, depth, and dissolved oxygen. Throughout the research, 3345 eggs and 176 larvae were analyzed. 57 species of eggs and larvae were identified. Eggs were not found in the natural reef (S3) in the summer and winter of 2015, while the highest egg abundance (212.83·100 m-3) was recorded in the natural reef (S1) in the summer of 2016. Larvae were not found in the natural reefs (S2 and S3) in the summer, autumn and winter of 2015 and in the artificial reefs (S4 and S5) in the summer and autumn in 2015 while the highest larvae abundance (8.12·100 m-3) on the artificial reef (S1) in summer 2016. Although the natural reefs had the highest number of species (30 species), the artificial reefs showed the lowest species diversity (17 species).

Postprandial sleep in short-sleeping Mexican cavefish.

Interaction between sleep and feeding behaviors are critical for adaptive fitness. Diverse species suppress sleep when food is scarce to increase the time spent foraging. Post-prandial sleep, an increase in sleep time following a feeding event, has been documented in vertebrate and invertebrate animals. While interactions between sleep and feeding appear to be highly conserved, the evolution of postprandial sleep in response to changes in food availability remains poorly understood. Multiple populations of the Mexican cavefish, Astyanax mexicanus, have independently evolved sleep loss and increased food consumption compared to surface-dwelling fish of the same species, providing the opportunity to investigate the evolution of interactions between sleep and feeding. Here, we investigate effects of feeding on sleep in larval and adult surface fish, and two parallelly evolved cave populations of A. mexicanus. Larval surface and cave populations of A. mexicanus increase sleep immediately following a meal, providing the first evidence of postprandial sleep in a fish model. The amount of sleep was not correlated to meal size and occurred independently of feeding time. In contrast to larvae, postprandial sleep was not detected in adult surface or cavefish, that can survive for months without food. Together, these findings reveal that postprandial sleep is present in multiple short-sleeping populations of cavefish, suggesting sleep-feeding interactions are retained despite the evolution of sleep loss. These findings raise the possibility that postprandial sleep is critical for energy conservation and survival in larvae that are highly sensitive to food deprivation.

Turbidity effects on prey consumption and survival of larval European smelt (Osmerus eperlanus)

The anadromous European smelt (Osmerus eperlanus) plays a key role in food webs of many riverine ecosystems in Europe. However, population sizes in several German rivers (e.g. Elbe or Weser rivers) have diminished drastically over the past decade. Turbidity has been considered one of the stressors affecting the successful recruitment of European smelt, as their early life stages may be particularly sensitive to changes in the abiotic environment. In this study, we investigated whether prey consumption and survival of European smelt larvae would be negatively affected by an acute exposure to elevated turbidity. We reared the larvae in the laboratory and exposed them in four separate trials (18 to 26 days post hatch, 9.5 ± 0.8 mm standard length, mean ± SD) to six turbidity levels (0–500 NTU, nephelometric turbidity units). We found that prey uptake increased at low turbidity levels and decreased at high turbidity levels, with an optimum between 100 and 200 NTU. Survival started to decrease at turbidity levels above 300 NTU. In addition, we conducted a systematic literature analysis in which we found that prey consumption of larval and juvenile fishes had been tested across a wide range of turbidity levels, mostly using pelagic (e.g. planktonic) prey items, with more studies focusing on perciform fishes and juvenile rather than larval life stages. Our empirical findings contribute to establishing thresholds for optimal larval European smelt performance under increased turbidity and provide valuable information for developing mechanistic models that assess potential consequences for European smelt recruitment dynamics.

Taurine improves juvenile Seriola rivoliana growth performance and biochemical profiles in blood serum and skeletal muscle

Taurine supplementation has shown survival and feeding efficiency in larval fish development. Thus, the present study aims to evaluate the effects of adding taurine to the longfin yellowtail (Seriola rivoliana) diet for 60 days. Fish (n = 270) were distributed in three treatments: T0 without taurine, T1, and T2, supplemented with taurine at 1 and 2%, respectively. Growth performance, blood serum biochemistry, fatty acid, and amino acid profiles in skeletal muscle were evaluated. Notable improvements (P &lt; 0.05) were observed in T1 and T2 in terms of specific growth rate (SGR) and weight gain (WG). Survival rates (SR) did not show significant differences (P &gt; 0.05). In addition, a decrease was observed in intraperitoneal fat (IPF). Still, an increase was observed in blood parameters, including higher total protein (TP) and globulin (GLO) concentration, as well as a reduction in cholesterol (CHO) levels. Changes in fatty acid profiles were also detected in skeletal muscle with an increase in omega-3 fatty acids (EPA and DHA) and elevation in taurine concentration in T2. The results showed that adding 20 g kg-1 of taurine to the diet improved growth, skeletal muscle, and blood serum biochemistry. Therefore, the use of higher taurine concentrations is recommended in future studies to understand fully the extent of the benefits to longfin yellowtail juveniles.

Correction: Effects of invasive bigheaded carp and environmental factors on larval fish growth

Correction: Effects of invasive bigheaded carp and environmental factors on larval fish growth

Community structure of whole pelagic copepods along the Kuroshio: Increase in the abundance and size in the north frontal area of the Kuroshio axis near the Japanese archipelago

The Kuroshio ecosystem is an important nursery ground for various fish species. Because the prey biomass and composition influence the recruitment of larval and juvenile fish, we investigated the variation in the abundance, carbon biomass, and community structure of copepods, which are the main prey for larval and juvenile fish, along the Kuroshio from the eastern coast of Taiwan to the Boso Peninsula, Japan from 8–November 24, 2015, using 100 μm-meshed plankton net samples. We identified two groups of stations (A and B) by the cluster analysis based on the composition and abundance for adult copepods (Q-mode). The total copepod abundance and carbon biomass were higher in Group A than in Group B. Of the dominant species assemblages classified by cluster analysis (R-mode), the abundance of species assemblages S2b and S3, which were composed of small-sized species (e.g., Oithona and Oncaea species), did not differ between Groups A and B, indicating that they were distributed abundantly throughout the Kuroshio region. On the other hand, the species assemblages (S1 and S2a) including the medium-sized calanoid copepods of coastal species and subtropical species (e.g., Paracalanus aculeatus and Clausocalanus furcatus) contributed to the high abundance and biomass of Group A. Group A occurred in the north-frontal area of the Kuroshio axis near the Japanese archipelago where chlorophyll a was high. This indicates that the community was changed by the bottom-up processes driven by nutrient supply from the subsurface layer in the north-frontal area. These results show that although the small-sized copepods were usually dominant in numerical abundance in the Kuroshio region as well as other oligotrophic oceans, the medium-sized copepods were an important component in the copepod community in water with high primary production. We concluded that the ecosystem in the north-frontal area downstream of the Kuroshio might provide optimal prey environments for diverse fish larvae and juveniles.

Ontogeny of daily rhythms in the expression of metabolic factors in Nile tilapia (Oreochromis niloticus) kept at two different temperature regimes: Thermocycle and constant temperature

The daily variations of temperature are one of the main synchronizers of the circadian rhythms. In addition, water temperature influences the embryonic and larval development of fish and directly affects their metabolic processes. The application of thermocycles to fish larvae has been reported to improve growth and the maturation of the digestive system, but their effects on metabolism are poorly understood. The aim of the present study was to evaluate the effect of two different temperature regimes, cycling versus constant, on the daily rhythms of metabolic factors of Nile tilapia (Oreochromis niloticus) larvae. For this purpose, fertilized eggs were divided into two groups: one reared in a 31 °C:25 °C day:night thermocycle (TCY) and another group maintained in a constant 28 °C temperature (CTE). The photoperiod was set to a 12:12 h light/dark cycle. Samples were collected every 4 h during a 24-h cycle on days 4, 8 and 13 post fertilization (dpf). The expression levels of alanine aminotransferase (alt), aspartate aminotransferase (ast), malic enzyme, glucose-6-phosphate dehydrogenase (g6pd), phosphofructokinase (pfk) and pyruvate kinase (pk) were analyzed by qPCR. Results showed that, in 13 dpf animals, most of the genes analyzed (alt, ast, malic, g6pd and pfk) showed daily rhythms in TCY, but not in the group kept at constant temperature, with most acrophases detected during the feeding period. An increase in nutrient metabolism around feeding time can improve food utilization and thus increase larval performance. Therefore, the use of thermocycles is recommended for tilapia larviculture.

Anoxic waters constrain the vertical distribution of fish developmental stages in an oxygen minimum zone

AbstractIn the Eastern Tropical North Pacific Oxygen Minimum Zone (ETNP‐OMZ), fish larvae undergo development amidst highly variable dissolved oxygen environments. As OMZs expand, understanding the implications of low‐oxygen environments on fish development becomes increasingly relevant for fisheries management and ecosystem modeling. Using horizontal zooplankton tows to track five oxygen levels (oxic [200 μmol/kg], hypoxic [100 μmol/kg] suboxic [10 μmol/kg], anoxic [&lt;1 μmol/kg], and deep [10 μmol/kg at ~ 1000 m depth]), this study analyzed the three‐dimensional distribution of fish larvae and adults across the ETNP‐OMZ. Results revealed a wide midwater anoxic core, extending from Costa Rica to Baja California, that was almost devoid of fish larvae (&lt; 1 larvae/1000 m3). Early larval stages primarily inhabited the oxic and hypoxic levels above the core, while postflexion and transformation stages occurred across a wider oxygen gradient, including the deep level below the anoxic core. Epipelagic species (e.g., Auxis sp.) were predominantly found in the surface oxic level, whereas coastal‐demersal species (e.g., Bregmaceros bathymaster, Ophidion spp.) were prevalent in the hypoxic level above the core. Meso‐bathypelagic species (e.g., Diogenichthys laternatus, Cyclothone spp.) were present throughout the study area, including below the anoxic core as transformation larvae and juveniles. These findings indicate that a vertical expansion of anoxic waters in OMZs could further constrain the habitat of epipelagic species, while also affecting the ontogenic vertical movements of meso‐bathypelagic species.

Simplified fish larval supply in coastal areas after a dam burst in Brazil

Coastal and estuarine systems play an important role in the maintenance of marine biodiversity, providing nursery, feeding, developmental and reproductive areas for terrestrial and aquatic species. The Fundão dam collapse is considered one of the biggest environmental disasters in Brazil, causing great social, economic and ecological damage in the affected areas. In our study, we used beta diversity and its components as a tool to monitor the spatio-temporal variation of fish larvae in four marine areas adjacent to the Doce River. The results show that the four areas undergo different spatio-temporal dynamics, with the composition of fish larvae in the Doce being simplified in the last years after the dam burst, compared to the other adjacent marine areas. In addition, turbidity is an important factor that has caused the homogenization of the larval composition of the Doce, demonstrating that mud resuspension events can cause a decrease in diversity and also suggesting the toxicity of the mud composition. The change from negative to positive additive and colonizing components in recent years suggests a slight recovery of diversity in the Doce compared to other marine areas. Finally, we have shown that some species may be tolerant to the impact, but with probable behavioral, energetic and physiological costs, which justifies the constant monitoring of these areas.

Anisakidosis in humans and animals and detection of anisakid larvae in fish and cephalopods in Korea: a literature review (1971-2022)

Anisakidosis in humans and animals and detection of anisakid larvae in fish and cephalopods in Korea: a literature review (1971-2022)