Han Kyu Lim

• Professor
• Professor at Mokpo National University

Shinorine is a mycosporine-like amino acid isolated from laver (Porphyra dentata), and interest in its functionality has increased recently due to increased production using yeast. There have been few reports on the pharmacological activity of shinorine, and we sought to find the pharmacological significance of shinorine. In the present study, we i...

The cultivation of abalone, a species with high economic value, faces significant challenges due to its slow growth rate and sensitivity to environmental conditions, resulting in prolonged cultivation periods and increased mortality risks. To address these challenges, we propose a novel probabilistic machine learning approach based on a Bayesian fr...

The purpose of this study was to investigate the protective effects of 7S,15R-dihydroxy-16S,17S-epoxy-docosapentaenoic acid (diHEP-DPA) in retinal pigment epithelial (RPE) cell damage. ARPE-19 cells, a human RPE cell line, were cultured with diHEP-DPA and Bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E), followed by exposure to BL. Cell via...

The starry flounder Platichthys stellatus, an economically important benthic fish species widely distributed throughout the North Pacific Ocean, exhibits poor heat tolerance, resulting in frequent adult mass mortality in aquaculture settings. Heat stress disrupts the energy metabolism of P. stellatus, elevating blood glucose and implying its sensit...

The Pacific abalone ( Haliotis discus hannai ) is the most economically valuable shellfish species in Northeast Asia, accounting for most of the shellfish production in South Korea. Despite the continuous improvement in the productivity of domestic abalone aquaculture, rapid seawater temperature changes caused by global warming have led to mass mor...

Haliotis discus hannai, a food with a high protein content, is widely consumed in Asian countries. It is known to have antioxidant, anticancer, and antibacterial effects. Since the biological significance of H. discus hannai hemolymph has not been widely studied, the objective of the present study was to purify phenoloxidase (PO) and investigate it...

Chum salmon (Oncorhynchus keta) is a species of anadromous salmonid inhabiting coastal rivers in the North Pacific and the Arctic in the Bering and is the most widely distributed among Pacific salmon species. It is an important fish species in Korea as the salmon releasing project is being actively carried out. This study was conducted to investiga...

Intermediate-term preservation of sperm assists the reproductive management of fish spermatozoa; however, no information is available on sperm of the spotted halibut, Verasper variegatus. We aimed to identify the optimum diluents, temperatures, dilution ratios, antibiotics, and antioxidants for sperm motility and cell viability. The diluents evalua...

Simple Summary The roughscale sole, Clidoderma asperrimum, is found in the East and West Seas of Korea, waters north of Hokkaido in Japan, as well as the East China Sea, the East Pacific, and the Canadian Maritimes. In 2021, this fish was categorized as an endangered species. Thus, there is a need to maintain gametes by freezing sperm. This study i...

To prevent the spread of disease in aquaculture, it is a need for a system to predict fish diseases while monitoring the water quality environment and the status of growing fish in real time. The existing research in predicting fish disease were image processing techniques. Recently, there have been more studies on disease prediction methods throug...

In fish hatcheries, sperm cryopreservation is a helpful tool for managing broodstock and artificial fertilization. However, cold shock can cause sperm injury resulting in decreasing sperm motility, low cell viability, structural damage to the plasma membrane and DNA fragmentation. This parameters are critical factor for the assessment of cryopreser...

The giant grouper, Epinephelus lanceolatus, is one of the most valuable tropical commercial fishes. The asynchronous maturity periods between males and females hampers breeding programs. Sperm cryopreservation for gamete conservation is important for fish reproduction. We evaluated the effects of storage for 1, 3, 4, and 5 years on cryopreserved sp...

Genes that influence the growth of Pacific abalone (Haliotis discus hannai) may improve the productivity of the aquaculture industry. Previous research demonstrated that the differential expression of a gene encoding a C-type lectin domain-containing protein (CTLD) was associated with a faster growth in Pacific abalone. We analyzed this gene and id...

Water temperature is the most important factor in fish farming as changes in water temperature cause physiological stress in fish. There have been few studies on physiological responses to high temperatures, which vary with aging. This study investigated the responses of juvenile and adult Platichthys stellatus to heat stress. Plasma cortisol, gluc...

The importance of the temperature tolerance of fish is increasing due to climate change caused by global warming. This study examined the expression of the heat shock protein 70 (HSP70) gene, and plasma cortisol and glucose levels, as a stress response in red-spotted and hybrid groupers during exposure to heat and cold shock. Temperature in the tan...

Roughscale sole (Clidoderma asperrimum) is only wild caught because basic reproductive research on this species is lacking and gamete production in an artificial setting has not been successful. Exogenous hormone treatment has been used to induce gonadal maturation and final spermiation in wild-caught individuals. In this study, the effects of an e...

The sexual maturation and spawning of teleosts are regulated by the external environment and the endocrine system. When the environmental conditions are artificially adjusted at a fish farm, the maturity and spawning of fish can be controlled. In this study, sexual maturation and spawning of the starry flounder, Platichthys stellatus, were artifici...

The aim of this research was to investigate different factors, including cryoprotective agents (CPAs), diluents, dilution ratios, equilibrium times, freezing rates, and thawing methods to optimize cryopreservation protocols for large yellow croaker (Larimichthys crocea). The parameters evaluated were sperm motility, sperm activity index (SAI), surv...

Simple Summary The dead end (dnd) gene encodes an RNA-binding protein that plays a role for migration of primordial germ cells (PGCs) to the gonadal region during embryogenesis in vertebrates. Here, the starry flounder (Platichthys stellatus) dead end (psdnd) gene was characterized and its expression patterns were analyzed. Full-length psdnd mRNA w...

The purpose of this study was to determine whether marine microorganism-derived astaxanthin has effects on coloration improvement and growth of the Hong Kong grouper (Epinephelus akaara). Juvenile and immature E. akaara were fed diets comprised of a mixture of commercial feed and biosynthetic astaxanthin obtained from Paracoccus haeundaensis to ana...

Microbial communities within animal intestines reflect various aspects of host physiological and metabolic status, including growth, feeding, and immunity. To find microbial indicators associated with faster abalone growth and hence the economics of abalone aquaculture, we performed a metabarcoding analysis of the intestinal microbial community in...

This study was performed as part of the effort to develop artificial seed production techniques for stone flounder Kareius bicoloratus, which has a great potential for farming in northeast Asian countries. To develop a sperm cryopreservation protocol that can be applied for artificial fertilization, we carried out experiments on the key factors for...

ABSTACT Growth rates of Pacific abalone Haliotis discus hannai are an important trait affecting the economic value in the abalone aquaculture industry. A reverse-transcription polymerase chain reaction (RT-PCR) analyses of tissues from H. discus hannai was conducted for sexually mature gonads to determine male- and female-specific target gene expre...

Simple Summary The spotted halibut, Verasper variegatus, is a popular fish species occurring naturally in the East China Sea and coastal areas of Korea and Japan. However, when reared in captivity, male and female spotted halibut do not usually mature synchronously. Maintaining production of this commercial fish in hatcheries through sperm cryopres...

Advances in the optimization of abalone culture can be achieved through a deeper understanding of the molecules modulating physiological functions including growth, metabolism, and reproduction. To identify neuropeptide molecules that play key roles in the modulation, transcriptome analysis of the ganglia (e.g., cerebral and pleuropedal ganglia) of...

Complete mitochondrial genomes of two Pleuronectid species, Clidoderma asperrimum and Verasper variegatus (Teleostei: Pleuronectiformes: Pleuronectidae) were analysed using the primer walking method. Their mitogenomes were 17,632 and 17,273 bp in total length, respectively and comprised 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfe...

The aim of the present study is to develop an eco-friendly, simple, cost-effective and single-step method for the synthesis of gold nanoparticles using Agrimonia pilosa (AP-AuNPs) aerial parts extract and evaluation of their antioxidant and cytotoxic activity. Synthesis of AP-AuNPs was observed by a color change from light yellow to wine-red, and c...

The fungus Chaetomium sp. is a causative agent of infections in humans and is ubiquitous in the natural environment. The secondary metabolites of this genus exhibit many biological activities, including antifungal activity and toxicity in mitochondria. In this study, we isolated cristazine from the fungus C. cristatum, which has the potential to in...

In this study, we identified four canonical calmodulin genes in the Pacific abalone, Haliotis discus hannai. Their full-length cDNAs were variable in the 5′ and 3′ untranslated regions, but highly similar (91–97%) in the coding region. Each of the genes encoded 149 amino acids, with 93–97% similarity among themselves and 94–98% similarity with huma...

We investigated various factors, including cryoprotective agents (CPAs), diluents, and freezing rates, to develop an optimal cryopreservation protocol for Epinephelus akaara sperm. In experiments using 10% dimethyl sulfoxide (DMSO), glycerol, and methanol with various diluents, 10% DMSO and 300 mM glucose yielded the highest post-thaw sperm motilit...

Astaxanthin is one of the major carotenoids used in pigment has a great economical value in pharmaceutical markets, feeding, nutraceutical and food industries. This study was to increase the production of astaxanthin by co-expression with transformed Escherichia coli using six genes involved in the non-mevalonate pathway. Involved in the non-mevalo...

Among the carotenoid biosynthesis genes, crtI gene encodes the phytoene desaturase (CrtI) enzyme, and phytoene desaturase convert phytoene to lycopene. Phytoene desaturase is involved in the dehydrogenation reaction, in which four single bonds in the phytoene are introduced into a double bond, eliminating eight hydrogen atoms in the process. Phytoe...

RNA isolation from the hepatopancreas of adult abalone is challenging, as indicated by the variable results of reverse transcription-polymerase chain reaction (RT-PCR) amplification. In this study, three RNA isolation methods were tested to evaluate their usefulness in RNA isolation from various abalone tissues. Unlike the conventional method (meth...

We studied the effects of acute and chronic exposure to air on the growth and stress response of juvenile olive flounder, Paralichthys olivaceus. To study the stress response, the water was completely drained from the experimental tank, and the stressed group was exposed to air for 5 minutes, after which the tank was refilled with water. This stres...

We report the draft genome sequences of a novel member of the Picornavirales isolated from Pacific abalone (Haliotis discus hannai). The full length of the assembled draft genome sequences, obtained by use of a next-generation sequencing technique, were 8,019 nucleotides, including an RNA-dependent RNA polymerase gene (5,088 nucleotides) and a caps...

Gonadotropin-releasing hormone (GnRH) is a key neuropeptide regulating reproduction in humans and other vertebrates. Recently, GnRH-like cDNAs and peptides were reported in marine mollusks, implying that GnRH-mediated reproduction is an ancient neuroendocrine system that arose prior to the divergence of protostomes and deuterostomes. Here, we evalu...

Carotenoids are natural lipid-soluble pigments, which are produced primarily by bacteria, algae, and plants. Many studies have focused on the identification, production, and utilization of natural sources of astaxanthin from algae, yeast, and crustacean byproducts as an alternative to the synthetic pigment, which is mostly used today. The aim of th...

The present study was designed to examine the potential for inducing ovulation in starry flounder (Platichthys stellatus) using gonadotropin-releasing hormone analog (GnRHa) and human chorionic gonadotropin (hCG) to assess whether starry flounder are differentially responsive to GnRHa and hCG. Female starry flounder were injected or implanted with...

In order to obtain a large number of fertilized eggs for seedling production, experiment was carried out examine effects of serotonin on spawning of the Pacific oyster Crassostrea gigas. The shorter response time to initial spawning in case of serotonin injection showed, the higher serotonin injected with 7.6-27 min. The response time to initial sp...

Experiments were carried out examine short-term effects of human chorionic gonadotropin (hCG) and long-term effects of luteinising hormone releasing hormone analogue (LHRHa) on milt production of the tongue sole Cynoglossus semilaevis. In the first experiment, each fish was implanted with a blank cholesterol pellet (control), 100 and 200?g LHRHa pe...

Abalones are gastropod mollusks belonging to the genus Haliotis. Pacific abalones are regarded as a very important marine gastropod mollusk in Korea, Japan, China, and also in food industries around the world. In Korea, 6 species of abalone have been reported to occur along the coasts: Haliotis discus hannai, Haliotis discus discus, Haliotis madaka...

These studies were conducted to compare the radulae of six species (Nordotis madaka, N. gigantea, N. discus discus, N. discus hannai, Sulculus diversicolor diversicolor, and S. diversicolor supertexta) of the family Haliotidae in Korea using the scanning electron microscope. As a result, teeth of all species has asymmetry rhipidoglossate form and b...

The Pacific abalone Haliotis discus hannai is used for commercial aquaculture in Korea. We examined the transcriptome of Pacific abalone Haliotis discus hannai siblings using NGS technology to identify genes associated with high growth rates. Pacific abalones grown for 200 days post-fertilization were divided into small-, medium-, and large-size gr...

The Pacific oyster Crassostrea gigas oocytes were exposed to 4 cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), methanol, or polyethylene glycol (PEG), each with 4 four concentrations (5, 10, 15, and 20%) and for 10, 20, 30 or 40 minutes for permeation. The oocytes were then fertilized, using normal sperm of the species. Fertilizat...

A phytoene synthase gene, crtB, was isolated from Kocuria gwangalliensis. The 1092 bp full length crtB has coding sequence of 948 bp and encodes a 316 amino-acids protein. The deduced amino acid sequence showed 70.9% identity with a putative phytoene synthase from K. rhizophila. An expression plasmid, pCcrtB, containing crtB gene was constructed, a...

Changes of oxygen consumption in juvenile giant grouper, Epinephelus lanceolatus were investigated in order to find out the physiological responses associated with freshwater and low salinities acclimation. Salinity changes in this experiment were set as follows; 35 psu (Exp. I) as control, decrease in the manners of 35{\rightarrow}20{\rightarrow}1...

This study is aimed to analyze the economic performance of black rockfish aquaculture by standardizing cost structures by region and farming size. The result of survey on farming and sale condition in each region, stocking density, survival rate, juvenile price, and unit production was the highest at Yeosu and Tongyeong, Heuksando showed the lowest...

These studies describe about genus Nordotis (Nordotis madaka, N. gigantea, N. discus discus, N. discus hannai) and suggest the taxonomic key. Also, adjustment and suggestion that confused Korean names in the Nordotis species from Korea.

The Morphological characteristics of four species of Korean Abalone species, Nordotis discus hannai, N. discus discus, N. gigantea, N. madaka were compared. then Phenotypic traits were characterized. we collected from coast of samchonpo, sacjon-si, Gyeongsangnam-do and jeju-do of korea 69 individual of Nordotis discus hannai from 2013 December to 2...

This study aimed to find an optimal diluent and cryoprotective agent (CPA) during cryopreservation of common Korean bitterling Acheilognathus signifier sperm. The bitterling is an endangered species in Korea, and this study will enable conservation and further technical development of artificial seed production. We tested the effects of cryopreserv...

Oxygen consumption (OC) of male black porgy Acanthopagrus schlegelii reared in freshwater (BFW) and seawater (BSW) during the reproductive period was , mg at , , mg at and , mg at , respectively. During the non-reproductive period, it was shown as , mg at , , mg at and , mg at , respectively. Thus, OC of BFW was higher than BSW both for non-reprodu...

Post-thawed larval rearing in Pacific oyster Crassostrea gigas was performed to investigate the survival rate with time course in three kinds of larvae cryopreserved. The highest survival rate and larval activity index (LAI) of post-thawed larvae were obtained from the permeation in 0.2 M sucrose and 2.0 M ethylene glycol (EG) at -1°C/min in freezi...

This study looked into recovery rate and histological changes in the gills of juvenile abalone Haliotis discus hannai by exposure time (3, 6, 12, 24 and 48 h) of different water temperatures (15, 20 and ) and salinities (30, 25, 20 and 15 psu) to understand reasons for the death of abalone exposed by low salinity water. In each water temperature, a...

Blood physiological responses, growth and survial rates were examined in juvenile starry flounder, Plotichthys stellatus exposed to different salinities (5, 10, 20, 33 ppt) for 90 days. At the end of the experiment, the plasma levels of Na+and osmolality were similar at 10, 20, 33 ppt, however, the values were significantly lower at 5 ppt compared...

The objective was to evaluate various extenders and cryoprotectants on postthaw motility of longtooth grouper (Epinephelus bruneus) sperm, based on sperm motility ratio (SMR), sperm velocity (SV), and morphological damage after thawing. To evaluate the optimal cryoprotectant for cryopreservation of longtooth grouper sperm, semen was diluted in 0.3...

The objective of this study was to find the optimal sugar level for motile parameters of spermatozoa of the yellow croaker Larimichthys polyactis. The spermatozoa were immotile in distilled water and motile in solutions containing different sugars. The highest spermatozoa velocity, motility, and duration of spermatozoa motility were obtained in sol...

The gonadosomatic index (GSI), sex steroid hormones and gonadal development of roughscale sole Clidoderma asperrimum cultured in indoor tank were investigated to evaluate its sexual maturation and reproductive cycle. The highest GSI values of female and male were (May) and (August), respectively. The reproductive cycle would be classified into four...

The effects of ovine prolactin (oPRL) on osmoregulatory ability (electrolyte balance, plasma osmolality and activity of gill chloride cells and gill Na+/K+‐ATPase) and stress responses (plasma cortisol, glucose, aspartate aminotransferase: AST and alanine aminotransferase: ALT) were investigated in black porgy transferred to freshwater (FW). Fish i...

This study aims to investigate the genes encoding prolactin (PRL) and prolactin receptors (PRLR) and their tissue-specific expression in starry flounder Platichthys stellatus. Starry flounder PRL gene consisting of five exons encodes an ORF of 212 amino acid residue comprised of a putative signal peptide of 24 amino acids and a mature protein of 18...

This study was performed to evaluate the food value of starry flounder Platichthys stellatus reared in different salinity. Results of salinity experiment in starry flounder clearly showed that there were no significant difference among cohesiveness and hardness except springiness. Proximate composition of muscle, crude lipid at the salinity 0 psu w...

Reproductive biology (maturation and spawning) of the female tongue sole Cynoglssus semilaevis were examined in 154 specimens caught from the west coast of Korea (between February and November 2010). Monthly changes of gonadosomatic index (GSI) and condition factor (CF) were peaked in September. Hepatosomatic index (HSI) showed a negative correlati...

The effects of various extenders and cryoprotectants on movable spermatozoa ratio (MSR), spermatozoa velocity (SV) and duration of spermatozoa motility (DSM) of post-thawed spermatozoa were examined. The MSR, SV and DSM of post-thawed sperm in artificial seminal plasma (ASP) extender were higher than those in marine fish Ringer's solution (MFRS) ex...

The effects of food, temperature, salinity, and rearing density on the survival and growth of the swimming crab Portunus trituberculatus, were studied. With regard to food, the larval survival rate to zoea IV was the highest (53.9%) in the mixed feed group (rotifers+ Artemia), followed, in order, by the rotifer, commercial feed, and Artemia groups....

The objectives of this present study were to assess the effects of varying dilutions, pH, temperature and cations on spermatozoa motile parameters (SMPs) in fish Larimichthys polyactis. Optimal SMPs were observed when emen was diluted in artificial seawater (ASW) at a ratio of 1 to 100, with temperature of 10 degreesC and pH 8.0. The spermatozoa of...

Storage of semen is useful for genetic studies and artificial breeding of fish. The aims of the present study were to find the best extender, dilution ratio, temperature, and antibiotic for cold storage of yellow croaker Larimichthys polyactis semen. The semen of yellow croaker was stored with artificial seminal plasma or marine fish Ringer's solut...

This study demonstrated that cryopreserved semen from dead fish can be used for seedling production. Yellow croakers, Larimichthys polyactis, were killed and stored at temperatures of 20°C or 0°C for 6 hours. At 2 hour intervals, semen from these fish was collected using abdominal pressure and evaluated for spermatozoa motility and semen cryopreser...

The reproductive cycle and batch fecundity of yellow croaker Larimichthys polyactis were examined in 981 specimens (286 males, 695 females) caught from waters around Mokpo, Busan, and Jeju-do (Korea) between February 2008 and January 2009. Males and females with ripe-stage gonads were collected between April and June, at which time the mean gonados...

Bioconcentration of perfluorinated compounds (PFCs) was studied in a biphasic (uptake and elimination) study with blackrock fish, Sebastes schlegeli. The blackrock fish was acclimated to varying salinities over a two-week period before the present study. Among the four selected PFCs: perfluorooctane sulfonate (PFOS), perfluoro-octanoic acid (PFOA),...

The sperm collection time, sex steroid hormones, and gonadal development of protandrous black porgy, Acanthopagrus schlegeli, acclimated in freshwater for more than 2 years were investigated to evaluate its reproductive capability. The gonadal development of black porgy reared in seawater and freshwater could each be classified into four successive...

Effect of potassium salt of perfluorooctane sulfonic acid (PFOS) on the osmoregulation of marine teleost (blackrock fish), Sebastes schlegeli, was investigated under varying salinities, by monitoring serum osmolality, Na(+), K(+), Cl(-), Ca(2+) and Mg(2+) concentrations in serum, serum glucose, and gill Na(+)-K(+) ATPase (NKA) activity. The fish wa...

Despite the reports of widespread occurrence of perfluorinated compounds (PFCs) in estuarine and coastal waters and open seas, little is known on the effect of salinity on bioaccumulation. In this study, effects of salinity on bioaccumulation of PFCs in Pacific oysters (Crassostrea gigas) were investigated. Furthermore, partitioning of PFCs between...

In order to standardize the juvenile abalone rearing technique, we selected sample farms by region in East, West and South coasts of Korea and Jeju island. We also have reviewed previous literature and visited farms to survey on the management of abalone juvenile production, spawning, hatching and so forth. Results of investigation are as follows:...

We experimentally determined the physico-chemical properties of seminal plasma as well as the sperm cryopreservation techniques of masou salmon, Oncorhynchus masou masou. Seminal plasma contained 18?1mmol/L potassium, 144?4mmol/L sodium, 116?3mmol/L chloride, 83.2?3.1mg/L calcium, 14.8?0.7mg/L magnesium, 45?9mg/L glucose, and 1.0?0.0g/L total prote...

Hur, J.W., Lim, H.K. and Chang, Y.J. 2008. Effects of repetitive temperature changes on the stress response and growth of olive flounder, Paralichthys olivaceus. J. Appl. Anim. Res., 33: 49?54. This study has examined the effects of repetitive and rapid changes of water temperature (such as sudden rises and falls) on the stress response and growth...

The present study aimed to find the best diluent and cryoprotectant for sperm cryopreservation of filefish Tham-naconus modestus. Two kinds of artificial seminal plasma (ASP1, ASP2), 0.3 M glucose and marine fish Ringer's solution (MFRS) were employed as diluent. Dimethyl sulfoxide (DMSO) and methanol as cryoprotectant were selected for sperm cryop...

Two experiments were designed to examine short-term effects of human chorionic gonadotropin (hCG), and long-term effects of gonadotropin-releasing hormone agonist (GnRHa), 17{\alpha}-hydroxyprogesterone (17P), and 17{\alpha},20{\beta}-dihydroxy-4-pregnen-3-one\;(17,20{\beta}P), alone or in combination, on milt production of the starry flounder Plat...

Understanding the nutritional condition and survival of fish larvae is of primary importance in mass larva culture because intensive mortality is concentrated during the larval period. In order to estimate growth and nutritional status based on biochemical indices of slime flounder, Microstomus achne, larvae reared under starved and fed conditions...