• Fisheries and Aquatic Sciences
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• v.27 no.9
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• pp.614-621
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• 2024

Channel catfish (Ictalurus punctatus), an introduced species in Vietnam, is widely cultured in the Northern provinces. The off-white grub disease in Channel catfish, caused by metacercariae of Dollfustrema bagarii (Digenea: Bucephalidae) lodged in internal organs, often results in heavy economic losses. Up to the present, there have been no specific guidelines for preventing and treating this disease. Here, we explore the potential treatment of infected channel catfish through the injection of Ivermectin. We evaluated the tolerance of channel catfish to the drug and determined the optimal dosage for treating off-white grubs disease. Healthy fish weighing 180-200 g received dosages of up to 3.250 mg/kg of body weight. The median lethal dose (LD₅₀) throughout a 24-hour period was 0.808 mg/kg body weight, with a confidence interval ranging from 0.583 to 1.118 mg/kg body weight. The infected fish used for treatment testing ranged in weight from 400 to 500 g. The value for the 24-hour median effective dose (ED₅₀) was 0.253 mg, and the appropriate therapeutic injection ranged from 0.300 to 0.700 mg per kg of body weight. Flowing the histopathological alterations, after the metacercariae were shriveled and died, the immune cells cleaned and eliminated them from fish.

• Genomics & Informatics
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• v.21 no.3
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• pp.39.1-39.15
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• 2023

DNA barcoding without assessing reliability and validity causes taxonomic errors of species identification, which is responsible for disruptions of their conservation and aquaculture industry. Although DNA barcoding facilitates molecular identification and phylogenetic analysis of species, its availability in clariid catfish lineage remains uncertain. In this study, DNA barcoding was developed and validated for clariid catfish. 2,970 barcode sequences from mitochondrial cytochrome c oxidase I (COI) and cytochrome b (Cytb) genes and D-loop sequences were analyzed for 37 clariid catfish species. The highest intraspecific nearest neighbor distances were 85.47%, 98.03%, and 89.10% for COI, Cytb, and D-loop sequences, respectively. This suggests that the Cytb gene is the most appropriate for identifying clariid catfish and can serve as a standard region for DNA barcoding. A positive barcoding gap between interspecific and intraspecific sequence divergence was observed in the Cytb dataset but not in the COI and D-loop datasets. Intraspecific variation was typically less than 4.4%, whereas interspecific variation was generally more than 66.9%. However, a species complex was detected in walking catfish and significant intraspecific sequence divergence was observed in North African catfish. These findings suggest the need to focus on developing a DNA barcoding system for classifying clariid catfish properly and to validate its efficacy for a wider range of clariid catfish. With an enriched database of multiple sequences from a target species and its genus, species identification can be more accurate and biodiversity assessment of the species can be facilitated.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.415-420
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• 2000

Distribution of S-100 protein-immunoreactive cells in the gastrointestinal tract of the catfish, Silurus asotus was investigated by PAP method. S-100 protein-immunoreactive cells were mainly observed just under the epithelium of the gastrointestinal tract. Immunoreactive cells were distributed numerously in the stomach and moderately in the middle part of the intestine, however, a few in the upper and lower part of the intestine.

• Journal of Aquaculture
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• v.17 no.1
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• pp.8-11
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• 2004

Milt of the catfish was stripped into immobilizing solution containing 175 mM NaCl and 30 mM Tris at pH 7.8 and was successfully cryopreserved after a stepwise freezing procedure. After stepwise thawing, motility of spermatozoa was slightly lower than that of fresh sperm. Batches of 40-80 eggs were fertilized with cryopreserved spermatozoa, after thawing and activation in solution containing 50 mM NaCl, 20 mM Tris and HCl at pH 7.8; this resulted in 62.2% fertilization success, compared to 70.6 % with fresh sperm.

• Development and Reproduction
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• v.19 no.3
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• pp.153-161
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• 2015

For the 2 years of farming, at the indoor circulating aquaculture system, four kinds of skeletal deformities were found among 60 Far Eastern catfish, Silurus asotus. Deformities saw jawbone's luxation, abnormality of upper lip and malocclusion. Spinal deformity was most fatal deformities with low weight and small length. Jawbone's luxation had 1 maxilla and 2 mandibles. Abnormality of upper lip had just lip was back over. Malocclusion's left maxilla and right maxilla were not balanced. This experiment was any deformities in this species through the deformity can grasp how it affects.

• Journal of Aquaculture
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• v.14 no.2
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• pp.67-71
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• 2001

Phosphorus is an essential element for growth and metabolism in fish. However high levels of phosphorus in the feed can lead to poor water quality of pond, and can also be a potential source of pollution, when pond water is released to the environment. In this study phosphorus supplemented diets containing 0.0, 0.9 or 1.9% of (dicalcium) phosphate were offered to channel catfish and changes in water quality of ponds and phosphorus levels in fish were measured. Higher level of (1.9%) supplementation of phosphorus in diet resulted in higher concentration of T-P and SRP in pond waters. Also it produced negative effects on fish production by lowering feed coefficient and rate of increment in body weight. Surplus phosphorus can affect fish growth and water quality of pond.

• Fisheries and Aquatic Sciences
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• v.27 no.9
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• pp.565-571
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• 2024

Ultrasound images can be utilized as a non-invasive method in the reproductive program. Striped catfish in various gonadal development were examined with a portable Mindray Model Z60Vet using the Convex probe at a frequency of 5 MHz. The results showed that the male gonads of immature striped catfishes were not distinguished from other visceral organs by using an ultrasonic technique. Ultrasound images in ovaries in stages II and III had significant differences. In ovary's group of stage III, the oocyte's dimensions on the ultrasound images were twice bigger than the group of stage II was. Before the premilitary injection, eggs displayed small, smooth, black dots, and 12h after the definitive dose, egg diameters raised twice and had brighter dots on the ultrasound images.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.225-226
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• 2003

Catfish (S. asotus) and bullhead (P. fulvidraco), economically important aquacultural species, belonging to order Siluriformes including two family Siluridae and Bagridae, respectively, are considered to be closely related to each other by various authors. Two fish species widely inhabit the slow river and stream that flows to the West Sea and South Sea in the Korean Peninsula. (omitted)

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.282-283
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• 2000

The egg development of various fishes is studied by various methods including electron microscopy(Matsuyama et al, 1991) and hormone treatment(Schoonbee et al. 1980). In addition to attempt to induce final maturation and spawning, the present experiments were conducted to investigate the influence of hCG upon reproductive cycles in catfish(Silurus asotus) with developing gonads and to stimulate the reproductive system during the rapid phase of gonadal development. (omitted)

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.5
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• pp.1364-1368
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• 2015

This study was performed to evaluate mineral contents of catfish Silurus asotus. As a result of mineral content, the mean content of the macro mineral was (in descending order): K (310.36-412.66 mg/100 g), P (186.42-223.02 mg/100 g), Na (35.32-57.87 mg/100 g), Mg (22.88-31.87 mg/100 g), Ca (9.05-13.07 mg/100 g). In comparison, the mean content of the micro mineral was (in descending order): Fe (0.26-0.95 mg/100 g), Zn (0.26-1.02 mg/100 g), Cu (ND-0.08 mg/100 g), Mn (0.01-0.03 mg/100 g). A proportion of mineral intakes with the dietary reference intakes for Koreans (KDRIs) set by the Korean Nutrition Society. Nutrient uptake proportion of mineral intakes was (in descending order): P (62.16%), K (20.71%), Mg (16.82%), Fe (13.02%), Zn (11.38%) Cu (10.94%), Na (6.59%), Ca (3.09%), Mn (0.96%). The mineral content was compared with the major protein food sources according to the Korea Health Statistics (2013) such as polished rice, pork, chicken, beef, eggs and milk. The calcium content contains; lower level of milk and eggs, chicken whereas higher levels of rice, pork and beef. Catfish has less iron content than major protein food source. Phosphorus and potassium contain higher level of major protein food sources.