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1.
Sci Total Environ ; 804: 150208, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798741

RESUMO

European sea bass (Dicentrarchus labrax) migrate towards habitats where salinity can reach levels over 60‰, notably in Mediterranean lagoons. D. labrax are genetically subdivided in Atlantic and Mediterranean lineages and have evolved in slightly different salinities. We compared Atlantic and West-Mediterranean populations regarding their capacity to tolerate hypersalinity with a focus on the involvement of the intestine in solute-driven water reabsorption. Fish were analyzed following a two-week transfer from seawater (SW, 36‰) to either SW or hypersaline water (HW, 55‰). Differences among lineages were observed in posterior intestines of fish maintained in SW regarding NKA activities and mRNA expressions of nkaα1a, aqp8b, aqp1a and aqp1b with systematic higher levels in Mediterranean sea bass. High salinity transfer triggered similar responses in both lineages but at different magnitudes which may indicate slight different physiological strategies between lineages. High salinity transfer did not significantly affect the phenotypic traits measured in the anterior intestine. In the posterior intestine however, the size of enterocytes and NKA activity were higher in HW compared to SW. In this tissue, nka-α1a, nkcc2, aqp8ab and aqp8aa mRNA levels were higher in HW compared to SW as well as relative protein expression of AQP8ab. For aqp1a, 1b, 8aa and 8b, an opposite trend was observed. The sub-apical localization of AQP8ab in enterocytes suggests its role in transepithelial water reabsorption. Strong apical NKCC2/NCC staining indicates an increased Na+ and Cl- reuptake by enterocytes which could contribute to solute-coupled water reuptake in cells where AQP8ab is expressed.


Assuntos
Bass , Animais , Bass/metabolismo , Brânquias/metabolismo , Intestinos , Osmorregulação , Salinidade , Água do Mar , ATPase Trocadora de Sódio-Potássio/metabolismo
2.
Chemosphere ; 287(Pt 4): 132356, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34600009

RESUMO

Nanoplastics (NP) (1-100 nm) are a growing global concern, and their adverse effects in marine organisms are still scarce. This study evaluated the effects of polystyrene nanoplastics (10 µg/L; 50 nm nPS) in the marine mussel Mytilus galloprovincialis after a 21 - day exposure. The hydrodynamic diameter and zeta potential of nPS were analysed, over time, in seawater and ultrapure water. A multibiomarker approach (genotoxicity (the comet assay) was assessed in mussel haemocytes, and the antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx)), biotransformation enzyme (glutathione - S - transferase (GST)), and oxidative damage (LPO)) was assessed in gills and digestive glands to evaluate the toxicity of nPS towards mussels. In seawater, aggregation of nPS is favoured and consequently the hydrodynamic diameter increases. Genotoxicity was highly noticeable in mussels exposed to nPS, presenting a higher % tail DNA when compared to controls. Antioxidant enzymes are overwhelmed after nPS exposure, leading to oxidative damage in both tissues. Results showed that mussel tissues are incapable of dealing with the effects that this emerging stressor pursues towards the organism. The Integrated Biomarker Response index, used to summarise the biomarkers analysed into one index, shows that nPS toxicity towards mussels are both tissue and time dependent, being that gills are the tissue most compromised.


Assuntos
Mytilus , Nanopartículas , Poluentes Químicos da Água , Animais , Biomarcadores/metabolismo , Brânquias/metabolismo , Mytilus/metabolismo , Nanopartículas/toxicidade , Estresse Oxidativo , Poliestirenos/metabolismo , Poliestirenos/toxicidade , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
3.
Biol Trace Elem Res ; 200(1): 375-384, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33641053

RESUMO

The release of heavy metals to the environment increased dramatically with industrialization and rapid economic development, and they have accumulated in aquatic organisms. The current study aimed toe valuate the physiological, immunological, and histological changes of crayfish (Procambarus clarkii) as bio-indicator for water quality. Crayfishes of the filed study group were collected from a polluted area (Rosetta branch, Egypt), where the highest concentration for heavy metals in water was for zinc (Zn). Besides the field study group, other crayfishes were exposed to different doses of ZnSO4 (0, 203, and 406 mg L-g) corresponding to Zn concentration (0, 46.03, and 92.06 mg L-1) respectively in aquariums for consecutive 4 days. Heavy metal concentrations in field water sample were arranged as follows: Zn > Fe> Pb > Cu and Mn > Ni > Co > Cd. The result revealed that Zn bioaccumulation increases significantly with the increase of water Zn concentration among the tested groups compared to the control group, where the highest bioaccumulation in all studied tissues (hepatopancreas, gills, and muscles) was observed in the field group and Zn high-dose group. Also, there was a significant increase in the levels of hemolymph uric acid, urea, creatinine, glucose, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase. Their highest concentrations were observed in the Zn high-dose group and the field group, while the levels of total protein, albumin, and cholesterol showed a significant decrease among the tested groups as compared with the control group. Their determined lowest concentrations were in the Zn high-dose group and field group. Among tested groups, total hemocytes and granulated hemocytes decreased significantly while hyaline hemocytes increased as compared with the control group. Histological damages were observed in hepatopancreas, gills, and muscles in the field and Zn groups. The present study showed that exposure to Zn caused physiological and histological changes in Procambarus clarkia. We assumed that Procambarus clarkia could be used as a sensitive bioindicator for monitoring water quality criteria.


Assuntos
Astacoidea , Metais Pesados , Animais , Monitoramento Ambiental , Brânquias/química , Metais Pesados/análise , Metais Pesados/toxicidade , Zinco
4.
Environ Pollut ; 292(Pt B): 118441, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34728326

RESUMO

Across the planet, winter de-icing practices have caused secondary salinization of freshwater habitats. Many amphibians are vulnerable because of permeable skin and reliance on small ponds, where salinity can be high. Early developmental stages of amphibians are especially sensitive to salt, and larvae developing in salt-polluted environments must osmoregulate through ion exchange in gills. Though ionoregulation in amphibian gills is generally understood, the role of gill morphology remains poorly described. Yet gill structure should affect ionoregulatory capacity, for instance in terms of available surface area. As larval amphibian gills also play critical roles in gas exchange and foraging, changes in gill morphology from salt pollution potentially affect not only osmoregulation, but also respiration and feeding. Here, we used an exposure experiment to quantify salinity effects on larval gill morphology in wood frogs (Rana sylvatica). We measured a suite of morphological traits on gill tufts-where ionoregulation and gas exchange occur-and on gill filters used in feeding. Larvae raised in elevated salinity developed larger gill tufts but with lower surface area to volume ratio. Epithelial cells on these tufts were less circular but occurred at higher densities. Gill filters showed increased spacing, likely reducing feeding efficiency. Many morphological gill traits responded quadratically, suggesting that salinity might induce plasticity in gills at intermediate concentrations until energetic demands exceed plasticity. Together, these changes likely diminish ionoregulatory and respiratory functionality of gill tufts, and compromise feeding functionality of gill filters. Thus, a singular change in aquatic environment from a widespread pollutant appears to generate a suite of consequences via changes in gill morphology. Critically, these changes in traits likely compound the severity of fitness impacts in populations dwelling in salinized environments, whereby ionoregulatory energetic demands should increase respiratory and foraging demands, but in individuals who possess structures poorly adapted for these functions.


Assuntos
Brânquias , Cloreto de Sódio , Animais , Humanos , Larva , Osmorregulação , Ranidae
5.
Chemosphere ; 287(Pt 2): 132103, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34488055

RESUMO

The study was planned to assess the acute toxicity of textile industry intermediate, 2 amino benzene sulfonate (2 ABS) through biochemical, genotoxic, histopathological and ultrastructural (SEM) analysis in liver and gills of fresh water fish Channa punctatus. The fish were subjected to two sublethal concentrations (2.83 mg/30 g b. w. and 5.66 mg/30 g b. w.) for 96 h. A significant (p ≤ 0.05) increment in the enzymatic activity of catalase (CAT), superoxide dismutase (SOD) and glutathione reductase (GR) was observed followed by decline on CAT-SOD after 96 h of exposure in both the tissues, whereas increment in malondialdehyde (MDA) levels were observed throughout the exposure period for both the concentrations. Comet assay also showed elevated tail length and % tail DNA throughout the exposure period, marking maximum damage after 96 h for both the tissues. Light microscopy divulged several anomalies including: infiltration of lymphocytes, sinusoidal dilations, necrosis, vacuolation in liver and secondary lamellae fusion, telangiectasia and epithelial uplifting in gills. The highest degree of tissue change (DTC) in liver (50.33 ± 0.88) and gill (42.33 ± 2.18) was recorded with the highest concentration after 96 h of exposure. Scanning electron microscopy (SEM) also reaffirmed several alterations in liver and gills of fish. The findings of the present study inflict changes in liver and gills, marking the interference of 2 ABS with the normal functioning by suppressing the enzymatic activity, accelerating the lipid peroxidation, enhancing DNA damage and by disrupting normal architecture of liver and gills, making it toxic towards the fish even at sub-lethal concentrations.


Assuntos
Brânquias , Poluentes Químicos da Água , Animais , Dano ao DNA , Água Doce , Rim , Fígado , Indústria Têxtil , Poluentes Químicos da Água/toxicidade
6.
Zootaxa ; 5027(1): 136-144, 2021 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-34811240

RESUMO

Brasilocaenis atawallpa was recently described based on male imago from Colombian Amazon. The original description does not contain a designation of type specimens or locality, and it just states that the type series was studied in order to perform the cladistic analysis. In this context, we herein designate the lectotype and paralectotypes of B. atawallpa and describe its nymphal stage. The nymphs were associated to B. atawallpa by the male genitalia extracted from mature nymphs. The nymphal stage of B. atawallpa can be differentiated from others known nymphs of the genus by absence of pointed microspines on opercular gill, fore coxa without projection, middle coxa with well-developed and semicircular projection, hind coxa with finger-like projection, fore and middle tarsal claws without denticles and hind margin of the ninth sternite almost straight.


Assuntos
Bivalves , Ephemeroptera , Holometábolos , Animais , Brânquias , Masculino , Ninfa
7.
Zootaxa ; 5004(3): 481-489, 2021 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-34811296

RESUMO

The new anchovy Stolephorus grandis n. sp., described on the basis of 10 specimens collected from Papua, Indonesia, and Australia, closely resembles Stolephorus mercurius Hata, Lavou Motomura, 2021, Stolephorus multibranchus Wongratana, 1987, and Stolephorus rex Jordan Seale, 1926, all having double pigmented lines on the dorsum from the occiput to the dorsal-fin origin, a long maxilla (posterior tip just reaching or slightly beyond the posterior margin of preopercle), and lacking a predorsal scute. However, the new species clearly differs from the others in having fewer gill rakers (3539 total gill rakers on the first gill arch in S. grandis vs. > 38 in the other species), a greater number of vertebrae (total vertebrae 4243 vs. fewer than 41), longer caudal peduncle (21.923.7% SL vs. 20.8%), and the depressed pelvic fin not reaching posteriorly to vertical through the dorsal fin-origin (vs. reaching beyond level of dorsal-fin origin).


Assuntos
Peixes , Perciformes , Animais , Austrália , Brânquias , Nova Guiné
8.
Zootaxa ; 5068(1): 81-98, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34810721

RESUMO

Two new species of Rhinogobius found in streams on central part of Palawan Island, Philippines are described. The two new species, Rhinogobius estrellae and Rhinogobius tandikan share unique transverse rows of sensory papillae on the cheek with Rhinogobius similis Gill, 1859, but differ from the latter in fin ray counts, arrangement of the scales, etc. The two new species are distinguished from each other by the pectoral-fin ray count, the longitudinal- and predorsal-scale counts, and colouration of the body. Rhinogobius estrellae new species and R. tandikan new species have been found allopatrically in a stream within Malatgao River system flowing into the Sulu Sea and in the Cayulo River flowing into the South China Sea, respectively. The Malatgao River system is the southernmost habitat of the genus Rhinogobius. Rhinogobius similis had been considered as the only member of the most basal lineage of this genus, but our mitochondrial genome analysis suggested that the two new species are additional members of this lineage. They are considered to be relicts of their common ancestor with R. similis, which probably had a wider distribution.


Assuntos
Perciformes , Animais , Peixes , Brânquias , Filipinas , Filogenia
9.
Zootaxa ; 5047(5): 575-582, 2021 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-34810822

RESUMO

A new species of Platybaetis viz., P. selvai sp. nov. is described herein based on larval collections from Tangon stream in the state of Arunachal Pradesh in Eastern region of Indian Himalaya. It can be differentiated by the following combination of characters: (i) posterior margin of abdominal segments IX with rounded 'U shaped spines; (ii) anterolateral margin of gills IVII with minute setae; (iii) claw with 78 denticles; (iv) paracercus composed of 1011 segments; (v) hindwing pads reduced, small. Brief ecological notes are appended.


Assuntos
Ephemeroptera , Animais , Brânquias , Índia , Larva , Rios
10.
Zootaxa ; 5052(1): 105-116, 2021 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-34810885

RESUMO

A new species of codling Physiculus megastomus sp. nov. is described based on the holotype and a subadult paratype collected from northern and eastern Taiwan. The new species is classified in Physiculus by the presence of a ventral light organ on the abdomen and a chin barbel, and the absence of vomerine teeth. It is distinguished from congeners in having a large mouth with the posterior end of the maxilla extending well behind the level of the posterior margin of the orbit, its length 57.8‒60.7% in head length (HL) and the combination of the following characters: both jaws bearing caniniform teeth; snout, suborbital area, and gular region fully scaled; ventral light organ small, its length 5.5‒6.7% of distance from the interventral line to the origin of the anal fin (InV-af), located approximately at the mid-point of InV-af; five gill rakers on the upper limb of the first gill arch. DNA barcoding supported the establishment of the new species.


Assuntos
Gadiformes , Animais , Brânquias , Taiwan
11.
Zootaxa ; 5023(1): 131-141, 2021 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-34810972

RESUMO

A new species of Tricorythopsis is described, illustrated and diagnosed based on nymphs from Par state, Brazil. Tricorythopsis similis sp. nov. is related to Tricorythopsis rondoniensis (Dias, Cruz Ferreira) based on abdominal terga IIIVII with acute tubercles medially located on posterior margins, and by the absence of the transversal line on operculate gill. However, the new species can be identified by the following combination of characteristics: general coloration yellowish brown, with blackish and purplish marks irregularly distributed; maxillary palp 1-segmented; segment II of labial palp shorter than segment I and longer than segment III; femora and tibiae with margins covered by long, pectinate setae; tarsal claws with 4 to 5 marginal denticles and 4+2 very small, submarginal denticles. This is the first species of Tricorythopsis recorded from Par state.


Assuntos
Ephemeroptera , Animais , Brasil , Brânquias , Ninfa
12.
Zootaxa ; 5032(1): 136-142, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34811138

RESUMO

The snailfish Osteodiscus abyssicola sp. nov. is described from a single specimen collected off the Pacific coast of Hokkaido, northern Japan, at a depth of 4,6714,744 m. It is distinguished from all currently recognized congeners by the following combination of characters: vertebrae 49; dorsal-fin rays 44; anal-fin rays 39; principal caudal-fin rays 8; pyloric caeca 5; mouth horizontal; teeth on both jaws simple and sharp, without cusps; upper and lower jaw symphyses without diastema; cephalic pore sizes moderate, similar to or slightly larger than nostril; gill slit extending ventrally to 2nd pectoral-fin ray base; pectoral fin notched; mandibular symphysis to center of anus 101.6% head length (HL); posterior edge of pelvic disk to center of anus 15.5% HL; epural 1, reduced; epipleural ribs absent. An emended diagnosis and key to the species of Osteodiscus are provided.


Assuntos
Gadiformes , Perciformes , Animais , Brânquias , Japão , Boca
13.
PLoS One ; 16(10): e0257774, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34624042

RESUMO

Previously we have shown that trypsin, a protein typically involved in digestion, is released from gills of both fresh and saltwater fishes into surrounding water under stress or injury. We have also shown that each species produces trypsin with different specific activities. In this report, using zebrafish as a model, we identified that trypsin induces an aversive response in zebrafish larvae and adult zebrafish. Since Protease-Activated Receptor 2 (PAR2) responds to trypsin, we tested whether the aversive response is dependent on the activation of PAR2 located on the zebrafish skin cells. Zebrafish larvae treated separately with neomycin and zinc sulfate also showed aversive response indicating neuromast, and olfactory cells are not involved in this aversion. Cultured keratinocytes from zebrafish showed a response to trypsin. Zebrafish larvae subjected to knockdown of par2a also exhibited reduced escape response. Similarly, par2a-deficient mutant larvae displayed no response to trypsin. Since it has been shown that stress activates PAR2 and sends signals to the brain as shown by the increased c-fos expression, we tested c-fos expression in adult zebrafish brains after trypsin treatment of adults and found enhanced c-fos expression by qRT-PCR. Taken together, our results show that the trypsin activates PAR2 on keratinocytes signaling the brain, and this pathway of trypsin-induced escape response will provide a unique communication mechanism in zebrafish. Furthermore, since PAR2 activation also occurs in pain/pruritus sensing, this model might be useful in elucidating components of signaling pathways in pain/pruritus.


Assuntos
Receptor PAR-2/genética , Pele/metabolismo , Tripsina/metabolismo , Peixe-Zebra/genética , Animais , Linhagem Celular , Brânquias/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Larva/efeitos dos fármacos , Larva/genética , Neomicina/farmacologia , Receptor PAR-2/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Pele/efeitos dos fármacos , Tripsina/efeitos adversos , Peixe-Zebra/metabolismo , Sulfato de Zinco/farmacologia
14.
Dis Aquat Organ ; 146: 67-73, 2021 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-34617512

RESUMO

Batrachochytrium dendrobatidis (Bd) is a pathogenic fungus known to infect amphibians and crayfish. In crayfish, Bd causes gill tissue damage, and in some cases, mortality. Most research has focused on the amphibian-Bd system, so to date, little is known about the effects of Bd on the crayfish host. Here, we studied the effects of sublethal exposure to Bd and the metabolites produced by Bd on crayfish Procambarus alleni survival, gill damage, and oxygen consumption (as a proxy for mass-specific metabolic rate). Oxygen consumption increased 24 h post-exposure to live Bd, indicative of a stress response, followed by a decrease in oxygen consumption over time (χ21 = 6.39, p = 0.012). There was no difference in response when comparing the crayfish exposure to live Bd and Bd-metabolites alone (χ21 = 2.70, p = 0.101), indicating that the metabolites may have been the causative agent responsible for the response. Additionally, oxygen consumption decreased with gill damage (tissue recession) in Bd-exposed individuals. We found that high doses of Bd cause outright mortality in crayfish, and we show here that sublethal Bd-induced inhibition of oxygen consumption could negatively impact crayfish in the field, possibly reducing their overall fitness. More research is needed to understand this understudied host-parasite system. It is essential that we incorporate the disease dynamics associated with Bd and crayfish in conservation disease models, as this is the only way to develop comprehensive community-based models.


Assuntos
Astacoidea , Brânquias , Animais , Batrachochytrium , Respiração
15.
Ecotoxicol Environ Saf ; 226: 112848, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34619476

RESUMO

Salinity changes will threaten the survival of aquatic animals. However, osmoregulatory mechanism of Coilia nasus has not been explored. Oxford Nanopore Technologies (ONT) sequencing was performed in C. nasus gills during hypotonic and hyperosmotic stress. 23.8 G clean reads and 27,659 full-length non-redundant sequences were generated via ONT sequencing. Alternative splicing, alternative polyadenylation, transcript factors, and long noncoding RNA were identified. During hypotonic stress, 58 up-regulated differentially expressed genes (DEGs) and 36 down-regulated DEGs were identified. During hypertonic stress, 429 up-regulated DEGs and 480 down-regulated DEGs were identified. These DEGs were associated with metabolism, cell cycle, and transport. The analysis of these DEGs indicated that carbohydrate and fatty acid metabolism were activated to provide energy for cell cycle and transport during hypotonic and hypertonic stress. Cell cycle was also promoted during hypotonic and hypertonic stress. To resist hypotonic stress, polyamines metabolism, ion absorption and water transport from extra-cellular to intra-cellular were promoted, while ion secretion was inhibited. During hypotonic stress, glutamine, alanine, proline, and inositol metabolism were activated. Ion absorption and water transport from intra-cellular to extra-cellular were inhibited. Moreover, different transcript isoforms generated from the same gene performed different expression patterns during hypotonic and hypertonic stress. These findings will be beneficial to understand osmoregulatory mechanism of Coilia nasus.


Assuntos
Brânquias , Transcriptoma , Animais , Perfilação da Expressão Gênica , Osmorregulação , Salinidade , Estresse Salino
16.
Aquat Toxicol ; 240: 105987, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34644674

RESUMO

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and the insecticide fipronil have been used widely in agriculture and detected in aquatic ecosystems, where they threaten wildlife. This study evaluated the whole-body bioconcentration and the biochemical and morphological changes in the gills of the neotropical fish Prochilodus lineatus exposed for 96 h to 2,4-D or fipronil as single compounds or as a mixture (2,4-D + fipronil). Fish exposed to either compound alone bioconcentrated 2,4-D (77 ± 23 ng g - 1 fish dry mass) and fipronil (789 ± 178 ng g - 1 fish dry mass). Fish exposed to 2,4-D + fipronil bioconcentrated fipronil (683 ± 73 ng g - 1 fish dry mass) but not 2,4-D. In the gills, catalase (CAT) and glutathione-S-transferase (GST) activities and the lipid peroxidation (LPO) level increased after exposure to 2,4-D. GST activity increased after exposure to fipronil. Conversely, no changes occurred in CAT and GST activities and LPO upon exposure to 2,4-D + fipronil. Histopathological changes such as hyperplasia, cellular hypertrophy, epithelial lifting, and vascular congestion were frequent in the gills of fish exposed to 2,4-D or fipronil individually or 2,4-D + fipronil. The mitochondria-rich cell (MRC) density increased on gill surface in fish exposed to fipronil or 2,4-D + fipronil. Only exposure to 2,4-D alone induced oxidative stress in the gills. Most morphological changes showed defense responses against the pesticides; however, hypertrophy and the change in MRC indicated compensatory responses to maintain the gill osmoregulatory function. The 2,4-D + fipronil mixture showed antagonistic interaction, except for the MRC fractional area at gill surface, which showed synergistic interaction. This is the first report showing antagonistic interaction of 2,4-D and fipronil in the gills after exposing fish to the mixture of both pesticides. The biochemical and morphological changes in gills endanger the gill functions, a phenomenon that implies an energy cost for fish.


Assuntos
Caraciformes , Herbicidas , Poluentes Químicos da Água , Ácido 2,4-Diclorofenoxiacético/toxicidade , Animais , Bioacumulação , Catalase/metabolismo , Caraciformes/metabolismo , Ecossistema , Brânquias/metabolismo , Glutationa Transferase/metabolismo , Herbicidas/metabolismo , Herbicidas/toxicidade , Peroxidação de Lipídeos , Fígado/metabolismo , Estresse Oxidativo , Pirazóis , Poluentes Químicos da Água/toxicidade
17.
Aquat Toxicol ; 240: 105985, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34634712

RESUMO

Alexandrium affine is a global harmful algal bloom (HAB)-forming dinoflagellate. In this study, the effect of non-toxin-producing A. affine on the gill and liver tissues of red seabream, Pagrus major, was analyzed over 24 h exposure and 2 h depuration phases. After exposure to three concentrations of A. affine (4,000, 6,000, and 7,000 cells mL-1), survival rates, respiration rates, immunities (lysozyme, total Ig), hepatic biomarkers (alanine aminotransferase, ALT; aspartate aminotransferase, AST; and alkaline phosphatase, ALP), lipid peroxidation (malondialdehyde, MDA), and antioxidant defense systems (glutathione, GSH; catalase, CAT; superoxide dismutase, SOD; glutathione peroxidases, GPx; and glutathione reductase, GR) were analyzed in gill and liver tissues. Dose-dependent decreases in survival and respiration rates were detected in red seabream. A. affine levels of to 6,000 and 7,000 cells mL-1 induced immunosuppression and hepatic impairment in both tissues, as measured by significant decreases in lysozyme activity, total Ig level, ALT, AST, and ALP content. The levels of GSH, CAT, SOD, GPx, and GR were significantly decreased in the gills and liver in response to 7,000 cells mL-1 of A. affine at 24 h, and MDA was elevated. However, different response patterns were observed between tissues in response to 4,000 cells mL-1. Activity of antioxidant defense enzymes was significantly elevated in the liver but decreased in the gills. This suggests that the gills were more vulnerable than the liver. In the case of 6,000 and 7,000 cells mL-1 treatments, higher susceptibility was also detected at 3 h in the gill compared to the overall responses of each parameter measured in liver. Taken together, direct attachment of A. affine to the gill tissue strongly affects immunity and antioxidant capacity of red seabream even after a short exposure period. These results could be helpful for understanding HAB-mediated effects in marine fish.


Assuntos
Dinoflagelados , Dourada , Poluentes Químicos da Água , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Dinoflagelados/metabolismo , Brânquias/metabolismo , Imunidade Inata , Peroxidação de Lipídeos , Fígado/metabolismo , Estresse Oxidativo , Dourada/metabolismo , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/efeitos adversos
18.
Ecotoxicology ; 30(10): 1997-2010, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34529203

RESUMO

Microplastics (MPs) are common environmental contaminants that present a growing health concern due to their increasing presence in aquatic and human systems. However, the mechanisms behind MP effects on organisms are unclear. In this study, zebrafish (Danio rerio) were used as an in vivo model to investigate the potential risks and molecular mechanisms of the toxic effects of polyethylene MPs (45-53 µm). In the zebrafish intestine, 6, 5, and 186 genes showed differential expression after MP treatment for 1, 5, and 10 days, respectively. In the gills, 318, 92, and 484 genes showed differential expression after MP treatment for 1, 5, and 10 days, respectively. In both the intestine and the gills, Gene Ontology (GO) annotation showed that the main enriched terms were biological regulation, cellular process, metabolic process, cellular anatomical entity, and binding. KEGG enrichment analysis on DEGs revealed that the dominant pathways were carbohydrate metabolism and lipid metabolism, which were strongly influenced by MPs in the intestine. The dominant pathways in the gills were immune and lipid metabolism. The respiratory rate of gills, the activity of SOD and GSH in the intestine significantly increased after exposure to MPs compared with the control (p < 0.05), while the activity of SOD did not change in the gills. GSH activity was only significantly increased after MP exposure for 5 days. Also, the MDA content was not changed in the intestine but was significantly decreased in the gills after MP exposure. The activity of AChE significantly decreased only after MPs exposure for 5 days. Overall, these results indicated that MPs pollution significantly induced oxidative stress and neurotoxicity, increased respiratory rate, disturbed energy metabolism and stimulated immune function in fish, displaying an environmental risk of MPs to aquatic ecosystems.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Ecossistema , Brânquias , Humanos , Intestinos/química , Plásticos/toxicidade , Polietileno/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Peixe-Zebra
19.
Ecotoxicology ; 30(10): 2011-2023, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34529205

RESUMO

Cadmium (Cd) is one of the most important marine environmental pollutants that can cause oxidative damage and apoptosis in living organisms, and mitochondria are the key cell organelles affected by Cd toxicity. In this study, we investigated the effect of Cd on the mitochondria in the gill cells of the clam Meretrix meretrix and the underlying mechanism of mitochondria-mediated apoptosis following exposure to the metal. Exposure of the clams to artificial seawater containing 1.5, 3, 6 and 12 mg L-1 Cd2+ led to swollen mitochondria compared with the untreated clams. The mitochondria also became vacuolated at the higher Cd2+ concentrations. Biochemical assays showed that monoamine oxidase (MAO) activity and mitochondrial membrane potential (Δψm) increased at 1.5 mg L-1 Cd2+, but decreased at higher Cd2+ concentrations, while the activities of malate dehydrogenase (MDH) and cytochrome oxidase (CCO) and the scavenging capacities of anti-superoxide anion (ASA) and anti-hydroxy radical (AHR) all decreased with increasing Cd2+ concentrations. Significant increases in the levels of malondialdehyde (MDA) and H2O2 as well as in the activity levels of caspase-3, -8, and -9 were also observed in the Cd2+-treated clams. The results implied that Cd might induce apoptosis in M. meretrix via the mitochondrial caspase-dependent pathway.


Assuntos
Bivalves , Poluentes Químicos da Água , Animais , Apoptose , Cádmio/metabolismo , Cádmio/toxicidade , Brânquias/metabolismo , Peróxido de Hidrogênio/metabolismo , Mitocôndrias/metabolismo , Estresse Oxidativo , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/toxicidade
20.
J Fish Dis ; 44(12): 2111-2123, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34585397

RESUMO

Amyloodinium ocellatum (AO) infection in silver pomfret (Pampus argenteus) causes extensive mortality. Insufficient information exists on the molecular immune response of silver pomfret to AO infestation, so herein we simulated the process of silver pomfret being infected by AO. Translucent trophosomes were observed on the gills of AO-infected fish. Transcriptome profiling was performed to investigate the effects of AO infection on the gill, kidney complex and spleen. Overall, 404,412,298 clean reads were obtained, assembling into 96,341 unigenes, which were annotated against public databases. In total, 2730 differentially expressed genes were detected, and few energy- and immune-related genes were further assessed using RT-qPCR. Moreover, activities of three immune-related (SOD, AKP and ACP) and three energy-related (PKM, LDH and GCK) enzymes were determined. AO infection activated the immune system and increased interleukin-1 beta and immunoglobulin M heavy chain levels. Besides, the PPAR signalling pathway was highly enriched, which played a role in improving immunity and maintaining homeostasis. AO infection also caused dyspnoea, leading to extensive lactic acid accumulation, potentially contributing towards a strong immune response in the host. Our data improved our understanding regarding the immune response mechanisms through which fish coped with parasitic infections and may help prevent high fish mortality in aquaculture.


Assuntos
Dinoflagelados/fisiologia , Doenças dos Peixes/imunologia , Perciformes/imunologia , Infecções Protozoárias em Animais/imunologia , Animais , Dinoflagelados/patogenicidade , Dispneia/veterinária , Doenças dos Peixes/parasitologia , Perfilação da Expressão Gênica , Brânquias/parasitologia , Perciformes/genética , Perciformes/metabolismo
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