The infection status of digenetic trematode metacercariae (DTM) was investigated in fishes from coastal lakes in Gangwon-do, the Republic of Korea (Korea). All fishes collected in 5 lakes were examined with the artificial digestion method. More than 10 species, i.e., Metagonimus spp., Pygidiopsis summa, Centrocestus armatus, Metorchis orientalis, M. taiwanensis, Clinostomum complanatum, Echinostoma spp., Stictodora spp., Diplostomum sp. and Diplostomid No. 1. by Morita (1960), of DTM were detected in fishes from 5 coastal lakes in Gangwon-do. Metagonimus spp. metacercariae were found in 52 (41.3%) out of 126 sea rundace, Tribolodon hakonensis, from 5 lakes, and their density was 14.6 per fish infected. P. summa metacercariae were detected in 48 (84.2%) out of 57 mullets from 5 lakes, and their density was 316 per fish infected. C. armatus metacercariae were detected in 7 (14.6%) T. hakonensis and 3 (15.0%) Tridentiger brevispinis from Hyang-ho, and 5 (19.2%) Acanthogobius flavimanus from Gyeongpo-ho. Stictodora spp. metacercariae were found in 4 fish species, i.e., Tridentiger obscurus, Tridentiger trigonocephalus, Chelon haematocheilus, and Acanthogobius lactipes, from Gyeongpo-ho. Total 15 C. complanatum metacercariae were detected in 2 (9.1%) crucian carp, Carassius auratus, from Songji-ho. M. taiwanensis metacercariae were found in T. hakonensis from Hyang-ho and Gyeongpo-ho and in Pseudorasbora parva from Gyeongpo-ho. Total 11 M. orientalis metacercariae were detected in 3 (6.3%) T. hakonensis from Hyang-ho. From the above results, it was confirmed that various species of DTM are infected in fishes from coastal lakes in Gangwon-do, Korea.
Carps ; Digestion ; Echinostoma ; Fishes ; Gangwon-do ; Goldfish ; Heterophyidae ; Korea ; Lakes ; Metacercariae ; Methods ; Republic of Korea ; Smegmamorpha

Present study was performed to survey infection status of digenetic trematode metacercariae in 2 alien fish species, Micropterus salmoides (largemouth bass) and Lepomis macrochirus (bluegill), in 2 rivers draining Chungcheongbuk-do, Republic of Korea. A total of 107 largemouth bass and 244 bluegills were caught in Daecheong-ho (ho=lake) and Musim-cheon (a branch of Geum-gang), in Chungcheongbuk-do April–July 2015. Additionally, 68 native fish of 5 species, i.e., Zacco platypus, Hemibarbus longirostris, Carassius auratus, Pseudogobio esocinus and Puntungia herzi, were caught from the same water bodies. All of the fish collected were examined by artificial digestion method. The metacercariae of Centrocestus armatus, Clinostomum complanatum, Metagonimus sp. and Diplostomum spp. were detected from 4 out of 5 native fish species in Daecheong-ho. However, any metacercariae were not found from 87 M. salmoides and 177 L. macrochirus in Daecheong-ho. In Musim-cheon, metacercariae of Exorchis oviformis and Metacercaria hasegawai were detected from 78% Z. platypus and 34% L. macrochirus, but any metacercariae not found in M. salmoides. We report here that the 2 alien fish species were less infected with the metacercariae than the native ones. Surveys on the metacercariae in the alien fish species in geographically various rivers should be undertaken for better understanding on the role of alien fish species in the trematode infections in Republic of Korea.
Bass ; Chungcheongbuk-do ; Digestion ; Emigrants and Immigrants ; Goldfish ; Heterophyidae ; Humans ; Metacercariae ; Methods ; Perciformes ; Platypus ; Republic of Korea ; Rivers ; Trematode Infections ; Water

The prevalence of Centrocestus formosanus metacercariae was investigated in ornamental fish purchased from a pet shop in Chiang Mai, Thailand, including Carassius auratus (goldfish), Cyprinus carpio (Koi), Poecilia latipinna (Sailfin Molly), Danio rerio (Zebrafish), and Puntigrus tetrazona (Tiger barb). The parasite species was identified by the morphology of worms as well as by a molecular approach using ITS2. The results showed that 50 (33.3%) of 150 fish examined were infected with the metacercariae. The highest prevalence was found in C. auratus (83.3%), and the highest intensity was noted in C. carpio (70.8 metacercariae/fish). The most important morphological character was the presence of 32–34 circumoral spines on the oral sucker. The phylogenetic studies using the rRNA ITS2 region revealed that all the specimens of C. formosanus in this study were grouped together with C. formosanus in GenBank database. This is the first report on ornamental fish, C. carpio, P. latipinna, D. rerio, and P. tetrazona, taking the role of second intermediate hosts of C. formosanus in Thailand. Prevention and control of metacercarial infection in ornamental fish is urgently needed.
Carps ; Databases, Nucleic Acid ; Goldfish ; Metacercariae* ; Parasites ; Poecilia ; Prevalence* ; Spine ; Thailand* ; Zebrafish

This study aimed to investigate the morphology and reconstruct the phylogenetic relationships of Centrocestus formosanus originating from 5 species of freshwater fish, i.e., Esomus metallicus, Puntius brevis, Anabas testudineus, Parambassis siamensis, and Carassius auratus, in Chiang Mai province, Thailand. Sequence-related amplified polymorphism (SRAP) and phylogeny based on internal transcribed spacer 2 (ITS2) and mitochondrial cytochrome c oxidase subunit 1 (CO1) were performed. The results showed similar morphologies of adult C. formosanus from day 5 after infection in chicks. C. formosanus originated from 4 species of freshwater fish had the same number of circumoral spines on the oral sucker, except for those from C. auratus which revealed 34 circumoral spines. The phylogenetic tree obtained from SRAP profile and the combination of ITS2 and CO1 sequence showed similar results that were correlated with the number of circumoral spines in adult worms. Genetic variability of C. formosanus also occurred in different species of freshwater fish hosts. However, more details of adult worm morphologies and more sensitive genetic markers are needed to confirm the species validity of C. formosanus with 34 circumoral spines originating from C. auratus in the future.
Adult ; Electron Transport Complex IV ; Fresh Water* ; Genetic Markers ; Goldfish ; Humans ; Phylogeny ; Spine ; Thailand* ; Trees

Animals ; China ; Genetics ; history ; Goldfish ; genetics ; History, 20th Century ; History, 21st Century

This study was performed in order to investigate the effects of taurine on cadmium poisoning in muscle, gill, and bone tissues of wild goldfish. For this experiment, 80 wild goldfish were divided into four experimental groups: 0.3 mg/L of cadmium and 0 mg/L of taurine (Group I), 0.3 mg/L of cadmium and 20 mg/kg of taurine (Group II), 0.3 mg/L of cadmium and 40 mg/L of taurine (Group III), and 0.3 mg/L of cadmium and 80 mg/L of taurine (Group IV). The results were as follows: The cadmium concentration in muscle tissue of wild goldfish was 0.65-3.21 mg/kg wet wt in Group I, whereas it decreased in Group IV. Levels of cadmium in gill tissue of wild goldfish were 16.57-42.39 mg/kg wet wt in Group I, 15.23-43.01 mg/kg wet wt in Group II, 15.11-39.56 mg/kg wet wt in Group III, and 13.15-38.55 mg/kg wet wt in Group IV (P < 0.05), suggesting that the cadmium concentration decreased in the experimental groups compared to control. The cadmium concentration in bone tissue of wild goldfish after 28 days was 0.52-9.75 mg/kg in Group II, whereas it increased in Group III (P < 0.05). In conclusion, taurine may have a preventive effect against cadmium accumulation in biological tissues.
Animals ; Bone and Bones ; Cadmium ; Cadmium Poisoning ; Gills ; Goldfish ; Muscles ; Taurine

OBJECTIVETo study the biological effects of nanoscale copper oxide (nCuO), zinc oxide (nZnO), cerium dioxide (nCeO2) and their mixtures on Carassius auratus.

METHODSJuvenile fish (Carassius auratus) were exposed to aqueous suspensions of nCuO, nZnO, and nCeO2 (alone and in mixtures) at concentrations of 20, 40, 80, 160, and 320 mg/L. The biomarkers-acetylcholinesterase (AChE) in brain, sodium/potassium-activated ATPase (Na+/K+-ATPase) in gill, and superoxide dismutase (SOD) and catalase (CAT) in liver-were determined after 4 days of exposure. Integrated biomarker response (IBR) was calculated by combining multiple biomarkers into a single value.

RESULTSAChE and SOD activities were significantly inhibited by all test metal oxide nanoparticles (NPs) at high concentrations (⋝160 mg/L) with the exception of nCeO2. Na+/K+-ATPase induction exhibited bell-shaped concentration-response curves. CAT activity was significantly inhibited at concentrations equal to or higher than 160 mg/L. The order of IBR values was nCeO2 ≈ nZnO/nCeO2 ≈ nCuO/nCeO2 < nCuO/nZnO/nCeO2 < nZnO < nCuO < nCuO/nZnO. The joint effect seemed to be synergistic for nCuO/nZnO mixtures, additive for the ternary mixture and less than additive or antagonistic for the binary mixtures containing nCeO2.

CONCLUSIONConcentration-dependent changes of enzymatic activities (AChE, Na+/K+-ATPase, SOD, and CAT) were observed in fish exposed to nanoscale metal oxides. IBR analysis allowed good discrimination between the different exposures and might be a useful tool for the quantification of integrated negative effects induced by NPs toward fish.

Acetylcholinesterase ; metabolism ; Animals ; Biomarkers ; metabolism ; Brain ; drug effects ; enzymology ; Cerium ; toxicity ; Copper ; toxicity ; Gills ; drug effects ; enzymology ; Goldfish ; metabolism ; Liver ; drug effects ; enzymology ; Metal Nanoparticles ; toxicity ; Random Allocation ; Sodium-Potassium-Exchanging ATPase ; metabolism ; Superoxide Dismutase ; metabolism ; Toxicity Tests ; Water Pollutants, Chemical ; toxicity ; Zinc Oxide ; toxicity

OBJECTIVETo assess the single and combined effects of estrone (E1) and 17β-estradiol (E2) on goldfish (Carassius auratus).

METHODSBatch tests were conducted. Serum levels of vitellogenin (VTG) and E2, gonadosomatic indices (GSI), gonadal DNA damage and liver 7-ethoxyresorufin-O-deethylase (EROD) activity were measured after exposure for 14 days.

RESULTSThe VTG level increased significantly in a concentration-dependent manner. The serum E2 level was significantly higher and the GSI level was significantly lower in goldfish after exposed to the 3 drugs. DNA damage occurred in treated samples and EROD activity was significantly suppressed 7 days after exposure. The joint effect of E1 and E2 was additive with regard to VTG induction.

CONCLUSIONThe results of our study highlight a series of effects of steroidal estrogens on goldfish. Further study is needed to confirm their effect as a whole.

Animals ; Cytochrome P-450 CYP1A1 ; metabolism ; DNA Damage ; drug effects ; Drug Combinations ; Estradiol ; pharmacology ; Estrone ; pharmacology ; Goldfish ; Gonads ; drug effects ; metabolism ; Male ; Vitellogenins ; blood

Understanding how the b-wave of the electroretinogram (ERG) is generated by full-field light stimulation is still a challenge in visual neuroscience. To understand more about the origin of the b-wave, we studied the contributions of gap junctions to the ERG b-wave. Many types of retinal neurons are connected to similar and different neighboring neurons through gap junctions. The photopic (cone-dominated) ERG, stimulated by a small light beam, was recorded from goldfish (Carassius auratus) using a corneal electrode. Data were obtained before and after intravitreal injection of agents into the eye under a photopic illumination level. Several agents were used to affect gap junctions, such as dopamine D1 and D2 receptor agonists and antagonists, a nitric oxide (NO) donor, a nitric oxide synthase (NOS) inhibitor, the gap junction blocker meclofenamic acid (MFA), and mixtures of these agents. The ERG b-waves, which were enhanced by MFA, sodium nitroprusside (SNP), SKF 38393, and sulpiride, remained following application of a further injection of a mixture with MFA. The ERG b-waves decreased following NG-nitro-L-arginine methyl ester (L-NAME), SCH 23390, and quinpirole administration but were enhanced by further injection of a mixture with MFA. These results indicate that gap junction activity influences b-waves of the ERG related to NO and dopamine actions.
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine ; Benzazepines ; Dopamine ; Electrodes ; Eye ; Gap Junctions ; Goldfish ; Humans ; Intravitreal Injections ; Light ; Lighting ; Meclofenamic Acid ; Neurons ; Neurosciences ; NG-Nitroarginine Methyl Ester ; Nitric Oxide ; Nitric Oxide Synthase ; Nitroprusside ; Quinpirole ; Retinal Neurons ; Sulpiride ; Tissue Donors

To understand the function of edges in perception of moving objects, we defined four questions to answer. Is the focus point in visual motion detection of a moving object: (1) the body or the edge of the object, (2) the leading edge or trailing edge of the object, (3) different in scotopic, mesopic and photopic luminance levels, or (4) different for colored objects? We measured the Optomotor Response (OMR) and Edge Triggering Response (ETR) of goldfish. We used a square and sine wave patterns with black and red stripes and a square wave pattern with black and grey stripes to generate OMR's and ETR's in the goldfish. When we used black and red stripes, the black leading edges stimulated an ETR under scotopic conditions, red leading edges stimulated an ETR under photopic conditions, and both black and red leading edges stimulated an ETR under mesopic luminance levels. For black and gray stripes, only black leading edges stimulated an ETR in all three light illumination levels. We observed less OMR and ETR results using the sine wave pattern compared to using the square wave pattern. From these results, we deduced that the goldfish tend to prefer tracking the leading edge of the pattern. The goldfish can also detect the color of the moving pattern under photopic luminance conditions. We decided that ETR is an intriguing factor in OMR, and is suitable as a method of behavioral measurement in visual system research.
Goldfish ; Light ; Lighting ; Track and Field