Fish

New morphological and molecular data were generated for trematodes recovered from the intestines of the fish Pseudaspius hakonensis from two locations in the south of the Russian Far East. Morphologically, these trematodes are identical to Pseudozoogonoides ugui (Microphalloidea: Zoogonidae) from Japan. According to results of phylogenetic analysis based on 28S rDNA sequence data, P. ugui was closely related to Zoogonoides viviparus , and P. subaequiporus appears as a sister taxon to these two species. Genetic distance values, calculated based on both 28S rDNA and ITS2 rDNA, between P...

Edwardsiella piscicida causes significant economic losses to the aquaculture industry worldwide. Phage-based biocontrol methods are experiencing a renaissance because of the spread of drug-resistant genes and bacteria resulting from the heavy use of antibiotics. Here, we showed that the novel Edwardsiella phage EPP-1 could achieve comparable efficacy to florfenicol using a zebrafish model of Edwardsiella piscicida infection and could reduce the content of the floR resistance gene in zebrafish excreta. Specifically, phage EPP-1 inhibited bacterial growth in vitro and significantly improved the zebrafish survival rate in vivo (P = 0...

This study evaluated the impacts of sulfamethoxazole (SMX) on antioxidant, immune, histopathological dynamic changes, and gut microbiota of zebrafish. SMX was carried out five groups: 0 (C), 3 mg/L (T3), 6 mg/L (T6), 12 mg/L (T12), and 24 mg/L (T24), with 5 replicates per group for an 8-weeks chronic toxicity test. It was found that SMX is considered to have low toxicity to adult zebrafish. SMX with the concentration not higher than 24 mg/L has no obvious inhibitory effect on the growth of fish...

Humans increasingly dominate Earth's natural freshwater ecosystems, but biomass production of modified ecosystems is rarely studied. We estimate potential fish total standing stock in USA reservoirs is 3.4 billion (B) kg, and approximate annual secondary production is 4.5 B kg y-1 . We also observe varied and non-linear trends in reservoir fish biomass over time, thus previous assertions that reservoir fisheries decline over time are not universal. Reservoirs are globally relevant pools of freshwater fisheries, in part due to their immense limnetic footprint and spatial extent...

Collectively locomoting animals are often viewed as analogous to states of matter in that group-level phenomena emerge from individual-level interactions. Applying this framework to fish schools and bird flocks must account for visco-inertial flows as mediators of the physical interactions. Motivated by linear flight formations, here we show that pairwise flow interactions tend to promote crystalline or lattice-like arrangements, but such order is disrupted by unstably growing positional waves. Using robotic experiments on "mock flocks" of flapping wings in forward flight, we find that followers tend to lock into position behind a leader, but larger groups display flow-induced oscillatory modes - "flonons" - that grow in amplitude down the group and cause collisions...

Yellow-cheek carp (Elopichthys bambusa) is a typical large and ferocious carnivorous fish endemic to East Asia, with high growth rate, nutritional value and economic value. In this study, a chromosome-level genome of yellow-cheek carp was generated by combining PacBio reads, Illumina reads and Hi-C data. The genome size is 827.63 Mb with a scaffold N50 size of 33.65 Mb, and 99.51% (823.61 Mb) of the assembled sequences were anchored to 24 pseudo-chromosomes. The genome is predicted to contain 24,153 protein-coding genes, with 95...

Thermal variations due to global climate change are expected to modify the distributions of marine ectotherms, with potential pathogen translocations. This is of particular concern at high latitudes where cold-adapted stenothermal fish such as the Notothenioids occur. However, little is known about the combined effects of thermal fluctuations and immune challenges on the balance between cell damage and repair processes in these fish. The aim of this study was to determine the effect of thermal variation on specific genes involved in the ubiquitination and apoptosis pathways in two congeneric Notothenioid species, subjected to simulated bacterial and viral infections...

Global warming has profound effects on the living conditions and metabolism of organisms, including fish. The metabolic rate of fish increases as the temperature increases within its thermal tolerance range. Temperature changes can trigger a range of physiological reactions, including the activation of the stress axis and the production of HSPs. Under stress conditions, HSPs play a crucial role in antioxidant systems, immune responses, and enzyme activation. This study examined the effects of heat shock products (HSPs) on fish under temperature stress...

The genus Jannaschia is one of the representatives of aerobic anoxygenic phototrophic (AAP) bacteria, which is a strictly aerobic bacterium, producing a photosynthetic pigment bacteriochlorophyll (BChl) a. However, a part of the genus Jannaschia members have not been confirmed the photosynthetic ability. The partly presence of the ability in the genus Jannaschia could suggest the complexity of evolutionary history for anoxygenic photosynthesis in the genus, which is expected as gene loss and/or horizontal gene transfer...

In mammals, physiological processes related to lipid metabolism, such as chylomicron synthesis or fatty acid oxidation (FAO), modulate eating, highlighting the importance of energostatic mechanisms in feeding control. This study, using rainbow trout (Oncorhynchus mykiss) as model, aimed to characterize the role of FAO and chylomicron formation as peripheral lipid sensors potentially able to modulate feeding in fish. Fish fed with either a normal- (24%) or high- (32%) fat diet were intraperitoneally injected with water alone or containing etomoxir (inhibitor of FAO rate-limiting enzyme carnitine palmitoyl-transferase 1)...

Ammonia in aquatic environments is toxic to fish, directly impacting their growth performance and development. Activation of autophagy can facilitate intracellular component renewal and enhance an organism's adaptability to adverse environments. Therefore, this study investigates the impact of autophagy on the yellow catfish under acute ammonia stress. In this study, the yellow catfish intraperitoneally injected with 0.9% sodium chloride were placed with 0 (CON group) and 125 (HA group) mg/L T-AN (Total ammonia nitrogen) dechlorinated water...

Fish rely on mucosal surfaces as their first defence barrier against pathogens. Maintaining mucosal homeostasis is therefore crucial for their overall well-being, and it is likely that secreted immunoglobulins (sIg) play a pivotal role in sustaining this balance. In mammals, the poly-Ig receptor (pIgR) is an essential component responsible for transporting polymeric Igs across mucosal epithelia. In teleost fish, a counterpart of pIgR has been identified and characterized, exhibiting structural differences and broader mRNA expression patterns compared to mammals...

Phthalates (PAEs) are a typical class of endocrine disruptors (EEDs). As one of the most commonly used plasticizers, they have received widespread attention due to their wide application in various countries and high detection rates in various environmental media. To be able to clarify the contamination status of PAEs pollutants in a typical northern cold-temperate urban river, 30 water samples from Yitong River in Changchun City, northern China were collected, during the 2023 dry season (March), normal season (May) and wet season (July)...

While eutrophication has led to serious habitat degradation and biotic shifts in freshwater ecosystems, most current studies have focused on changes in community assemblages, with few considering the effect of eutrophication on food webs. We conducted a field study in subtropical headwater streams with a gradient of nutrient levels to examine the effect of increasing water nutrients on food webs by using the long-chain polyunsaturated fatty acid eicosapentaenoic acid (EPA) as a measure of the nutritional quality of food...

Zebrafish are an outstanding model for assessing the involvement of genes in paediatric cataracts. Gene discovery for cataracts is enhanced by manipulation of the genome of zebrafish embryos and comparing the phenotypes of mutant progeny with the wildtype embryos. However, wildtype laboratory fish can also develop cataracts, potentially confounding the results. In this study, we compared the baseline cataract rate between two commonly used wildtype laboratory strains, AB and TL, and also an outbred transgenic line with mCherry reporter...

Prolactin is involved in regulating various physiological activities of vertebrates and is one of the most momentous pituitary hormones. However, not enough attention is currently paid to prolactin, especially in teleost. This paper aims to gather, organize, and analyze recent studies on the regulation and functions of prolactin. By comparing with other animal groups, it highlights the significant role of prolactin in fish reproduction, immunity, growth, and osmotic pressure regulation, as well as the upstream and downstream factors that may be involved in the regulation of prolactin functions, were introduced to provide a theoretical basis for the in-depth study and potential practical application of prolactin...

Di(2-ethylhexyl) terephthalate (DEHTP) is an alternative plasticizer widely used in numerous consumer products, replacing di(2-ethylhexyl) phthalate (DEHP). Hence, DEHTP has been frequently detected in the environment and humans. As a structural isomer and functional analog of DEHP, DEHTP is a suspected endocrine disruptor. Here, we evaluated DEHTP thyroid-disrupting effects in embryo-larval and adult male zebrafish. We also investigated sex hormone disruption in the adult zebrafish. After 5- and 7-day exposure to DEHTP, significant increases in whole-body thyroid hormonal levels were observed in the larval fish...

No water body is resilient to afflicts of algal bloom, if goes unmanaged. With the increasing trend of intensification, eutrophication and climate change, Labeo rohita (rohu) is highly anticipated to suffer from the deleterious effects of bloom and eventually its toxins. A comprehensive study was conducted to understand the toxicopathological effects of microcystin-LR (MC-LR) in rohu following intraperitoneal injection of 96 h-LD50 dose i.e., 713 μg kg-1 . Substantial changes in micro- and ultrastructural level were evident in histopathology and transmission electron microscope (TEM) study...

Manzala Lake was sampled to assess the concentrations and possible ecological risks of heavy metals. The mean heavy metal levels in the muscles of Nile tilapia, Flathead grey mullets and African catfish were 0.01, 0.15 and 0.29 mg/kg, respectively, for mercury; 3.16, 4.25 and 4.74 mg/kg for arsenic; 1.01, 0.87 and 0.95 mg/kg for lead; and 0.05, 0.12 and 0.06 mg/kg for cadmium. The levels of heavy metals exceeded their maximum permissible limits in most samples. The EDIs of some metals were higher than their PTDIs or BMDLs...

Biodiversity conservation and management in urban aquatic ecosystems is crucial to human welfare, and environmental DNA (eDNA)-based methods have become popular in biodiversity assessment. Here we report a highly overlooked source of significant false positives for eDNA-based biodiversity assessment in urban aquatic ecosystems supplied with treated wastewater - eDNA pollution originating from treated wastewater represents a noteworthy source of false positives. To investigate whether eDNA pollution is specific to a certain treatment or prevalent across methods employed by wastewater treatment plants, we conducted tests on effluent treated using three different secondary processes, both before and after upgrades to tertiary treatment...