• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.71-71
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• 2019

The genus Cenchrus (Poaceae), containing ca. 23 species, is distributed throughout Australia, Africa, Indian sub-continent, and America. In Korea, Cenchrus longispinus (Hack.) Fernald, especially introduced to Daecheong Island in 1999, is one of the most hazardous invasive plant which causes serious environmental threats, biodiversity damages and physically negative impact on humans and animals. Based on the next-generation sequencing (NGS) technology, we characterized the chloroplast (cp) genome sequences of C. longispinus which contains a large single copy (LSC; 80,223 bp), a small single copy (SSC; 12,449 bp), separated by a pair of inverted repeats (IRs; 22,236 bp). Additionally, we analyzed the cp genome sequences of Cenchrus echinatus L. which contains a large single copy (LSC; 80,220 bp), a small single copy (SSC; 12,439 bp), separated by a pair of inverted repeats (IRs; 22,236 bp). These cp genomes consist of 75 unique genes, 4 rRNA coding genes, 33 tRNA coding genes and 21 duplicated in the IR regions, of which the gene content and organization are similar to the other Poaceae cp genomes. We selected 40 potential regions in cp genomes of two Cenchrus species and one Korean Pennisetum species to develop new single nucleotide polymorphism (SNP) markers for identifying C. longispinus based on amplification-refractory mutation system (ARMS) technique. The markers, inferred from SNP in matK and ndhF genes, show effectiveness to recognize C. longispinus from C. echinatus and Korean native species Pennisetum alopecuroides (L.) Spreng.

• Journal of fish pathology
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• v.34 no.1
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• pp.55-61
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• 2021

One of the major problems in fish production is that parasite-induced episodes of disease can result in significant impacts to the health of stock, mortalities and, economical losses. Seabreams are economically important fish in both the capture fishery and aquaculture sectors in Oman and represent potential species for aquaculture. The current study set out to investigate infection of polyopisthocotylean monogeneans on the gills of wild goldlined seabream, Rhabdosargus sarba, caught from Musairah region in Oman. The prevalence, mean intensity and abundance of polyopisthocotyleans on 145 fish was found to be 52.41%, 5.65 and 3.04, respectively. Three species of microcotylid parasite were isolated, one being Atrispinum acarne while the remaining two species require further study to identify them. There was no significant difference in the infection rate between host sex, however, parasite burdens were higher on larger sized fish (p<0.05) and were found to favour the first gill arch (p< 0.05). The study found that the sample of Rhabdosargus sarba landed in the waters around Musairah are heavily infected, with a predominantly immature population of microcotylids. Further work is required to better understand the potential risk each species poses to the health of its host before a decision is made on the suitability of new candidate fish species for commercial aquaculture.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.274-285
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• 2007

The subfamily Chrominae of damselfishes (Teleostei: Pomacentridae) includes the genus Chromis and Dascyllus. They are found throughout the tropical oceans and form a major component of coral reef communities. There are 5 species of the Chrominae currently recognized in Korea. This study was conducted to infer phylogenetic position of two Korean Chromis species and one Dascyllus species within general category of their each genus in worldwide level. This study also includes one species of Japanese Dascyllus. In the phylogenetic analysis, the Japanese D. aruanus grouped with D. aruanus previously reported from French Polynesia. Korean Chromis fumea grouped with Australian C. nitida and the p-distance value between the two species is relatively very low (0.047). Korean C. notatus grouped together with C. flavomaculata (New Caledonia). In the sequence analysis of some Korean and Japanese damselfishes, there was no sequence variation between D. melanurus (Jeju, Korea) and D. melanurus (Indo-Pacific), but the sequences of the two populations were different in only one nucleotide sites from that of D. melanurus in Indonesian Archipelago. The sequences of Dascyllus aruanus (Japan) were different in two nucleotide sites from it in French Polynesia. There were high difference between the sequences of two Korean species, Chromis fumea and Korean C. notatus. The variations among mitochondrial cytochrome b sequences indicate that the gene sequence could be used as DNA barcode for identification of local populations of D. aruaus and D. melanurus as well as species level.

• The Journal of Fisheries Business Administration
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• v.25 no.1
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• pp.37-59
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• 1994

Many studies to cope with the present problems of Korean coastal and offshore fisheries has been performed, but these were done partly in necessities and general studies for Korean inshore and offshore fisheries are in early stage. Most of these studies adopted analytical way of approach for each fishery individually and they could not reflect the effect of correlated interaction among fisheries on the several common species/stocks, and thus optimal effort allocation was impossible. To consider general fisheries and optimal effort allocation among competing mixed species, a linear programming (LP) approach is applied in this study and introduced into 16 important inshore and offshore fisheries with 13 constraining species which were chosen by annual yield order. This study is not based on the biological interaction among species (i.e., prey - predator system) but the technological interaction between species and fishing efforts. For the application of LP model in these fisheries, the standardization of fishing efforts through different fishing gears could not be successful and a new way of effort standardization through CPUE for vessel tonnage was originated. Total standardized fishing effort on a particular species i, Ei, is computed as the linear summation of standardized fishing effort generated by each fishery j. That is, (equation omitted) where $f_{j}$ is the total vessel tonnage of fishery j and aij is the coefficients contributing to the standardized fishing effort per ton for species i taken in fishery j. The total fishing effort level on species i due to both directed fishing and by - catch can thus be accounted in the aij's. Optimal effort allocation among the j fisheries may be considered a minimizing problem (minimize $\Sigma$ $f_{j}$), subject to the constraints that standardized fishing effort levels on particular species are maintained at, above, and below certain predefined levels. Fishing effort goals for individual species can be based on various biological and/or economic criteria, i.e., fishing effort level generating maximum sustainable yield and/or maximum economic yield. But in this study the $F_{0.1}$ criteria which was accepted as an approximate level for $F_{mey}$ by Outland and Boerema's (1973) study. The findings of this study are, (1) LP model can be applied to the Korean inshore and offshore fisheries giobally. (2) Through a new way of combining multiple different fisheries' efforts for a particular species together generating standardized fishing effort, Schaefer curve could be applied to the complex system successfully. (3) The results of this study for total reduction scale were mostly the same as those of prior studies, but different much from the individual scales of reduction. This study showed the necessities for exploitation of more concrete parameters to put into consideration of profitability of fisheries and social factors, and this model can be modified according to the actual constraints. Also, considering the age structure of stocks, this model can be developed into better one for better fisheries management.ent.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.2
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• pp.141-149
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• 2004

The aim of this study was to test the validity of the hypothesis that the karyotypes of four species of Lepilemuridae were formed spontaneously from their ancestral hybrid karyotype. Hypothetical ancestral haploid Karyotype of Lepilemuridae is composed of 18 autosomes and X chromosomes. Lepilemur mustelinus karyotype has four tandem fused chromosomes and one Robertsonian translocated chromosome pairs. Lepilemur septentrionalis septentrionalis karyotype has only two pairs of translocated chromosomes. We reconstruct and suggest ancestral karyotype of LMU(ancLMU) and LSS(ancLSS), from which all four studied species were derived. Hybrids of ancLMU and ancLSS were formed and produce differently fused equilibrated gametes via circular form arrangement during gametogenesis. Five unit of trivalent homologous chromosome pairs were engaged in a circular form to give new gamete corresponding to the karyotype of L. dorsalis, orientation of one unit of trivalent was inversed in the circle to gave new gamete corresponding to the karyotype of L. leucopus. Seven homologous chromosome pairs were engaged in circular form to give haploid karyotype of Lepilemur ruficaudatus. Only one homologous chromosome pair is dissociated and the other chromosome pairs rearranged in the circle to form haploid karyotype of Lepilemur edwardsi. The new gametes could be produced from these circular forms. When the new gamete fertilized with the same type of gamete, The new homozygote is produced as existing L. dorsalis, L. leucopus, L. edwardsi and L. ruficaudatus. These results support the theory that new species could be formed in hybrid population through activated chromosome fusion, chromosome rearrangement in circular from at zygotene stage and production of equilibrated gametes to form homozygote new species.

• Ocean and Polar Research
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• v.29 no.3
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• pp.273-282
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• 2007

For an efficient management and utilization of marine biodiversity information, we made an attempt to develop the Korea Marine Biodiversity Information System (KoMBIS), building a species name inventory of Korea marine organisms. The inventory includes 17 organism groups: phytoplankton, zooplankton, algae and halophyte, sponges, cnidarians, rotifers, nematodes, bryozoans, brachiopods, molluscs, echiurans, annelids, arthropods, echinoderms, urochordates and fish. The species names were collected from 37 different references and reviewed for validity by taxonomists, which resulted in 9,798 valid names in addition to 1,845 synonyms. The Korea marine species inventory is the first one of this kind, for previous Korean species name inventories were mostly composed of terrestrial and freshwater organisms. KoMBIS, the information system developed, contains not only the species name but also information on morphological and ecological characteristics such as distribution, DNA barcode, and references. This system is convenient for the inputting of new data and servicing users through the internet, so that management and utilization of the biodiversity information is more efficient. Linking the DNA barcode data with species information provides an objective measure for identification of a species, which accommodates the recommendation of Consortium for the Barcode of Life, and makes the Korea marine biodiversity information compatible with international databases. Considering the frequent exchange of marine organisms internationally via ballast water and such issues as climate change, this information system will be useful in many areas of marine biodiversity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.4
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• pp.569-574
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• 2023

A single specimen (30.35 mm standard length) of Ptereleotris evides was collected from the southern coast of Jejudo Island, Korea, in September 2017 during a skin diving outing. Ptereleotris evides is characterized by having a slightly elongated body, six spines on the 1^st dorsal fin, one spine and 25 soft rays on the 2^nd dorsal fin, 22 pectoral fin rays, one spine and four soft rays on the pelvic fin, one spine and 25 soft rays on the anal fin, and no disc in pelvic fin. This species differs from the congeneric species, P. hanae and P. heteroptera in having no elongated rays on the caudal fin and a black spot at the ventral margin of the caudal peduncle, respectively. Molecular analysis results based on mitochondrial DNA cytochrome c oxidase subunit I (COI) sequences showed that our specimen almost corresponded to P. evides (99.82%) sequences from registered at the NCBI. As this is the first record of P. evides in Korean waters, we propose a new Korean name for it, "Ga-mak-cheong-hwang-mun-jeol".

• Natural Product Sciences
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• v.4 no.4
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• pp.253-256
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• 1998

Chemical investigation of hot hexane extract of the stem bark of Gordonia ceylanica afforded a new triterpenoid, $3{\beta}-acetoxy-28-hydroxyolean-12-ene$ (1) and three other oleanane triterpenoids, $3{\beta}-hydroxyolean-12-ene$ (2), $3{\beta}-acetoxyolean-12-ene$ (3), and $3{\beta}-acetoxyolean-12-en-11-one$ (4) which are new to the species. Structure of compound 1 was suggested by $^1H\;NMR,\;^{13}C\;NMR$ and MS spectral data and confirmed by converting to previously reported compound, erythrodiol diacetate (5). Structures of 2, 3 and 4 were established by comparison of the spectral data with the previously reported compounds. Further the acid hydrolysate of 4 was identical with $3{\beta}-hydroxyolean-12-en-11-one$ (6).

• ALGAE
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• v.26 no.3
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• pp.243-251
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• 2011

Environmental conditions can influence the morphology of local biota through phenotypic plasticity or local adaptation. Macroalgal morphologies are often associated with wave-exposure conditions. We investigated the relationship between morphology and wave exposure in two common endemic subtidal macroalgae, Carpophyllum angustifolium and C. maschalocarpum, from the East Cape of New Zealand. Morphological comparisons were made between individuals from two sites and four different wave-exposure zones, as defined by fetch and barnacle composition. Of the seven morphological traits measured in C. angustifolium, only total length varied, and individuals were longer in more wave-exposed environments between the two exposure zones where the species were found. In contrast, total length, stipe thickness and vesicle presence all varied significantly between exposure zones in C. maschalocarpum. C. maschalocarpum specimens were shorter with thinner stipes, and fewer individuals had vesicles in the more wave-exposed zones. Morphological traits of both species also varied between sites, suggesting that other influences are important for determining species morphology. Further study is needed to investigate the role of phenotypic plasticity and genetic variability for driving morphological variation in C. angustifolium and C. maschalocarpum.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.4
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• pp.424-429
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• 2019

Two juvenile (9.48 and 10.11 mm in standard length) specimens of the lanternfish Notoscopelus japonicus, belonging to the family Myctophidae, were collected from the waters around Busan and Jeju Island in February 2017. This species is characterized by having melanophores along the dorsal side of the body and one photophore (PO5) in front of the pelvic fin. It is distinguished from Benthosema pterotum in having many melanophores on the dorsal side and a single photophore (PO5) on the trunk. N. japonicus is also distinguished from its congeneric N. resplendens and N. caudispinosus in having no melanophores at the base of the anal fin. Analyzing 521 base pairs of the 16S rRNA sequence, the specimens were identical to N. japonicus adults from Japan (K2P distance <0.004). This is the first record of N. japonicus in Korea, and we propose a new Korean name "Deung-jum-saet-bi-neul-chi" for this species.