• YAKHAK HOEJI
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• v.30 no.5
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• pp.253-265
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• 1986

Among 230 species of herbal drugs screened, thirty one show the anthelmintic activities in vitro against Clonorchis sinensis, the chinese liver fluke. The active substances have been isolated and their structures identified. Some of the active substances and their derivatives have been synthesized, followed by anthelmintic activity tests. The extracts from the active drugs cause damages in organs of the adult worm in the hepatic duct of rabbit. Some fresh water fish, which function as bad hosts for the fluke, excrete defense substances against the cercaria of the fluke. The defense substances have been isolated from Cyprinus carpio and Cyprinus carpio nudus, followed by structural identification. The results are summarized as follows: l) The bark of Machilus thunbergii as well as the seed of Schizandra chinensis contain meso-dihydro-guaiaretic acid as the anthelmintic component. Among derivatives synthesized, 4-phenyl-1-((3, 4-dihydroxyphenyl)-, 4-phenyl-1-(3-hydroxy-4-methoxy phenyl)-and 4-phenyl-1-(4-hydroxy-3-methoxy phenyl)-2, 3-dimethyl butanes show considerable activities. Administration of the bark extract mainly damages the bladder of the adult worm. 2) The active substance from the roasted fruit of Prunus mume is 2-hydroxymethylfurfural. This substance is produced during the roasting process. Administration of the fruitextract causes a damage of the bladder of the adult worm. 3) The active substance from the root of Scutellaria baicalensis is 5.2'-dihydroxy-6, 7, 8, 6'-tetramethoxyflavone. 4) Beside alantolactone, a very strong anthelmintic component is contained in the root of Inula helenium. Administration of the root extract causes irreversible damage on the worm, affecting mainly the reproductive organs. 5) The cercaricidal substances from the epidermis of C. carpio and C. carpio nudus are ethyl linoleate and linoleic acid, respertively. 6) The cercaricidal substances from various kinds of fresh water fish have different $R_f$ values, implying that the defense substances are species-specific. Unexpectedly, the fish with good host function, for example Pseudorasbora parva, excrete the defense substances, too. The defense substances are possibly organ-specific in individual species; the organs essenstial for the existence of the species excrete the defense substances, allowing other parts to be invaded by the cercaria. 7) The cercaricidal fraction of Carassius carassius is detected only in the fish which have been collected during the summer time from May to September, Its secretion is not dependent on water temperature. Thus, it seems to be possible that the secretion of the defense substance would be stimulated through a contact between the fish and cercaria.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.11
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• pp.1651-1658
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• 2008

This study was conducted to determine the effects of dietary supplementation of either 100 mg/kg chito-oligosaccharide (COS) or chlortetracycline (CTC) with corn-soybean-fish meal on immunity in broiler chickens. A total of 147 one-day old male broiler chicks were randomly allocated to 3 treatments with 7 replicate pens per treatment and 7 birds per pen. The experimental diets consisted of a control diet based on corn, soybean and fish meal without COS and any antibiotic supplement and similar diets supplemented with either CTC (80 mg/kg from d 1 to 21 and 50 mg/kg from d 22 to 42) or COS (100 mg/kg from d 1 to 42). During the entire experimental period, all birds had ad libitum access to diets and water. The main immune organ indices, T-lymphocyte proliferation, serum cytokine concentrations, serum NO level and serum iNOS activity were measured on d 21 and d 42. On d 21, broilers fed 100 mg/kg COS had improved (p<0.01) indices of spleen, thymus, and bursa of Fabricius compared with the control and CTC birds. Birds receiving 100 mg/kg COS had higher (p<0.05) serum concentrations of $IL-1{\beta}$, IL-6, IgM, NO and iNOS than birds on the control treatment. Serum $Ca^{2+}$ level of birds fed 100 mg/kg COS tended to be higher (p = 0.049) than in birds fed CTC. On d 42, the birds fed 100 mg/kg COS had higher (p<0.05) concentrations of TNF-${\alpha}$ and IgM in serum than birds in both the CTC and control treatments. Birds fed 100 mg/kg COS had a higher concentration of IFN-$\gamma$ than the control group. In conclusion, dietary supplementation of COS appeared to improve the immunity of broilers by promoting the weight of the main immune organs, increasing IgM secretion, stimulating microphages to release $TNF-{\alpha}$, $IL-1{\beta}$, IL-6 and IFN-$\gamma$, and activating iNOS to induce NO.

• Animal Systematics, Evolution and Diversity
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• v.32 no.1
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• pp.28-37
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• 2016

We describe the morphological characteristics of two morids, Gadella jordani and Physiculus japonicus, belonging to the order Gadiformes, based on Korean specimens collected from the Korean ocean. Two specimens of Gadella jordani was first collected from Jeju Island, Korea and the East Sea, Korea, in 2013-2014. This species is characterized by 8, 67-69 dorsal fin rays, 66-71 anal fin rays, 5+13 gill rakers, no barbel on the lower jaw, no vomerine teeth, and a ventral luminous organ closer to the anus than to the interventral line. We described it as the first record to the Korean fish fauna, and proposed the new Korean name "Min-su-yeom-dae-gu-sok" for the genus Gadella, and "Min-su-yeom-dae-gu" for the species G. jordani. Physiculus japonicus was first reported by Koh and Moon in the year 1999 based on a single specimen in Korea. However, no study has been attempted to describe the morphological characteristics in Korea since then. In 2013-2014, three specimens of P. japonicus was collected from Jeju Island, Korea and the East Sea, Korea, and we redescribe P. japonicus in detail. This species is characterized by 9-10, 63-64 dorsal fin rays, 70-73 anal fin rays, 3+7-8 gill rakers, a short barbel on the lower jaw, and a ventral luminous organ equidistant between the interventral line and the anus.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.223-228
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• 2016

The anatomy and histology of the olfactory organ in Oryzias sinensis was researched using a stereo microscope and light microscope. In the gross structure, the paired olfactory organs on the dorsal part of the head consist of two nostrils (a circular anterior nostril and a slit posterior nostril in a distance), a single olfactory chamber and a single accessory nasal sac. In the histological study, the epithelium of the olfactory chamber is classified into both sensory and non-sensory regions. The sensory epithelium consists of olfactory receptor neurons, supporting cells, basal cells and vesicles, and is islet in distributional pattern. The non-sensory epithelium is composed of stratified epithelial cells and two types of mucous cells (acidic and neutral cells). The epithelium of the accessory nasal sac has swollen stratified epithelial cells, mucous cells with a rich glycoprotein. Such an olfactory anatomy and histology of O. sinensis may reflect its habitat surrounding stagnant and polluted water.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.129-136
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• 2000

Differentiation and development of the digestive organ of the black sea bream, AcanHepagus schlegeli were studied by means of histological methods. The hatched lawn if TL(total length) $2.0 mm (n=10)$ had a yolk sac of $1,000{\times}590 {\mu}m$ and simple straight digestive tract, which was composed of cuboidal epithelium. In the pre-larval stage of TL $3.5 mm$, digestive tract could be distinguished into esophagus, stomach and intestine, and the exocrine glands were appeared in the pancreas. In this stage mucosal folds, eosinophilic granule cells and brush border were observed in the posterior intestine. Yolky materials were completely absorbed and the brush border was recognized in the free surface of anterior intestine in TL $3.7 mm$. In the stomach mucosal folds began to appear from TL $4.0 mm$. In this time the zymogen granules were recognized in the cytoplasm of pancreatic exocrine cells. In the post-larval stage ranged from $4.5 to 5.0 mm$ in TL, hepatic cords started to develop, and the mucous secretory cells of PAS positivewere observed at esophagus and intestine. In the post-larval stage ranged from $6.3 to 7.0 mm$ in TL, histological layer of esophagus and intestine could be distinguished into serous membrane, muscular layer, submucosal layer and mucosal layer. From over TL $9.0 mm$, stomach could be distinguished into cardiac, fundic and pyloric portion, and the gastric gland began to appear at mucosal fold of fundic stomach. In the juvenile stage ranged from $10.0 to 11.0 mm$ in TL, histological structures of esophagus and intestine were similar to those of adult. From over TL $15.0 mm$, histological structures of stomach were similar to those of adult. Structural and functional digestive organ of black sea bream was present from the juvenile stage ranged from $15.0 to 17.0 mm$ in TL.

• Journal of fish pathology
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• v.7 no.2
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• pp.127-149
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• 1994

Histopathological studies on the two lymphomyeloid organs of spleen and head kidney in tilapia, Oreochromis niloticus, were carried out to clarify the significance on the morphological characteristics of melano - macrophage centers (MMCs) which are varied in different physiological and pathological conditions of teleosts. To examine the histological changes by the artificial modification of the immunological states, tilapia were treated intraperitoneally with FKC and LPS of Edwardsiella tarda, and orally with dexamethasone, and then followed by the intraperitoneal injection of colloidal carbon for chasing the macrophages. There were marked differences in phagocytic avidity of macrophages, and accumulating patterns of carbon - ladening macrophages into the MMCs among the test groups. In the non - pretreated control group, carbon - ladening macrophages were densely accumulated at 12th and 20th day within the MMCs of head kidney and spleen, respectively. And, in the groups treated with bacterial antigens (FKC & LPS), the macrophages were more rapidly and densely aggregated within MMCs. But in the group with dexamethasone, only a few carbon particles were detected in both organs. Any compactly isolated form of particles was not found in this group. From the present results, it was strongly suggested that certain changes in immunological states of tilapia influence on the morphology of MMCs including the frequency of appearance, sizes, aggregating patterns or outlines. Therefore, morphology of MMCs would be very important in the interpretation for histopathological findings seen in the teleost's lymphomyeloid organs.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.368-375
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• 2022

Gut contents analysis is essential to predict the impact of organisms on food source changes due to variations of the habitat environment. Previous studies of gut content analysis have been conducted using traditional methods, such as visual observation. However, these studies are limited in analyzing food sources because of the digestive process in gut organ. DNA metabarcoding analysis is a useful method to analyze food sources by supplementing these limitations. We sampled marine fish of Pennahia argentata, Larimichthys polyactis, Crangon affinis, Loligo beka and Sepia officinalis from Gwangyang Bay and Yeosu fisheries market for analyzing gut contents by applying DNA metabarcoding analysis. 18S rRNA v9 primer was used for analyzing food source by DNA metabarcoding. Network and two-way clustering analyses characterized the relationship between organisms and food sources. As a result of comparing metabarcoding of gut contents for P. argentata between sampled from Gwangyang Bay and the fisheries market, fish and Copepoda were analyzed as common food sources. In addition, Decapoda and Copepoda were analyzed as common food sources for L. polyactis and C. affinis, respectively. Copepoda was analyzed as the primary food source for L. beka and S. officinalis. These study results demonstrated that gut contents analysis using DNA metabarcoding reflects diverse and detailed information of biological food sources in the aquatic environment. In addition, it will be possible to provide biological information in the gut to identify key food sources by applying it to the research on the food web in the ecosystem.

• Development and Reproduction
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• v.18 no.2
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• pp.99-106
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• 2014

Fish larvae are immediately exposed to microbes from hatching to maturation of their lymphoid organs, therefore effective innate mechanisms is very important for survival. However, the knowledge of the development of immune system in fish is limited and in demand now. In vertebrates, recombination-activating gene 1 (RAG-1) and immunoglobulin M (IgM) have been considered as very useful markers of the physiological maturity of the immune system. In this study, the expression of the both genes was assessed throughout the early developmental stages of olive flounder larvae (5-55 dph) and used as markers to follow the development of immune system. RAG-1 and IgM mRNA expression was detectable at 5 dph and remained so until 55 dph. These patterns of expression may suggest that the olive flounder start to develop its function around 5 dph. Tissue distribution was found that both genes mRNAs are only expressed in the immune-related organ such as spleen, kidney and gill. The early detection of IgM mRNA led to the investigation of its presence in oocytes. Both RAG-1 and IgM mRNA transcripts were detected in unfertilized oocytes, suggesting that they are maternally transferred. The biological significance of such a phenomenon remains to be investigated.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.133-140
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• 2004

The histopathologieal effects of his(tri-n-butyltin)oxide (TBTO) on the flounder, Paralichthys otivaceus were examined by means of histological methods. The experimental fishes were exposed to 0.17, 0.36, 0.60, 3.20, 6.30, 12.50 ${\mu}g \;L^{-1}$TBTO concentrations for 42 days. Histopathological change of the fish exposed to TBTO is dependent on the exposure duration and concentration. In the lower concentrations early histological changes included activated mucous cells and chloride cells, capillary hyperemia and epithelial hyperplasia in the gill; hepatocyte activation, degeneration of bile duct and pancyeatic zymogen reduction in the hepatopancreas; and capillary hyperemia, appearance of eosinophilic cell and melano-macrophagocytes in the kidney. At the higher concentrations histological changes of dysfunctionality included epithelial lifting and deformation of the lamellae in the gill; pycnosis and cytoplasmic degeneration of hepatocyte; pycnosis of haemopoietic cell and deformation of renal tubules and glomerulus in the kidney. It is indicated that TBTO induced histopathological changes in the fish as other aquatic pollutants.

• Development and Reproduction
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• v.14 no.3
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• pp.179-184
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• 2010

Water temperature influences on various key biological events in fish, but the internal pathway of the temperature effects are not well understood. Heat shock proteins (HSPs), known to respond in the level of cells to many environmental factors including temperature, could improve our understanding on the pathway. Some biological processes such as gonadal development and sex differentiation in the Nile tilapia Oreochromis niloticus is particularly sensitive to water temperature. In this study, we have investigated the expressions of HSP70 and HSP90 genes in young tilapia at an ordinary temperature ($28^{\circ}C$) and elevated water temperature ($36^{\circ}C$). The distribution of the expressions of HSP70 and HSP90 mRNA in this species were found to be almost ubiquitous, being detected in all tissues studied here (brain, gonad, liver and muscle), suggesting the house keeping functions of these genes. Heat shock by elevating temperature from $28^{\circ}C$ to $36^{\circ}C$ significantly increased the expression of HSP70 mRNA in the gonad, liver and muscle for several hours (P<0.05) (brain tissue was not examined for this). The increased level of HSP70 gene expression recovered to the level at control temperature ($28^{\circ}C$) when fish were kept continuously at high temperature ($36^{\circ}C$) for 24 hours. Contrary to this, expression of HSP90 mRNA did not show significant increase in the gonad and muscle by the same heat shock (P>0.05), except in the liver where the expression of HSP90 mRNA increased continuously for 24 hours at $36^{\circ}C$. The results obtained in this study suggest that response to temperature change in different tissue or organ may utilize different heat shock proteins, and that HSP70 may have some importance in temperature-sensitive gonadal event in the Nile tilapia.