• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.497-504
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• 2006

Biodiversity is closely related to the conservation of ecosystems. Ecosystems provide more subtle, but equally essential, services. Microorganisms decompose human's waste and renew the soils that produce our food crops. Biodiversity in Korean paddies encompass 54 families and 107 species of freshwater invertebrates. In terms of the number of aquatic insects affected by different sources, the order starting with the highest population was swine slurry > chemical fertilizer > fresh straw with reduced fertilizers > control. The number of freshwater invertebrate and aquatic macro-invertebrate in surface water of the plots without insecticidal application were 2 and 2.1 times greater than in fields receiving insecticide applications, respectively. The soil microfungal flora of the 85 isolates paddy fields in Korea was 30 species in 13 genera and 11 isolates were unidentified yet. Agricultural policy should be changed to assist the conservation of biodiversity because until now the agricultural ecosystems have been negatively affected from the development of high-yield varieties to enhance food production, and the expansion of fertilizer and chemical use. For the conservation of agricultural ecosystems, agricultural practices with less investment and more resource saving, as well as enhancing the safety of agricultural and livestock products are essential. Finally, this paper was written for the contribution for the development of environmentally friendly farming systems with neighboring or whole ecosystems.

• Fisheries and Aquatic Sciences
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• v.10 no.1
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• pp.16-23
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• 2007

Myostatin (GDF8) is a growth factor that limits muscle tissue growth and development in vertebrates. We isolated a myostatin-like gene (Py-MSTN) from the marine invertebrate, the scallop Patinopecten yessoensis. Py-MSTN was highly expressed in the adductor muscle and in the gill unexpectedly. Amino acid analysis showed that Py-MSTN has 49% amino acid sequence identity and 64% similarity to human myostatin (Hs-MSTN), and 42% identity and 61% similarity to myoglianin, the only invertebrate homolog. These results indicated that Py-MSTN may be functionally similar to the vertebrate MSTN than the invertebrate homolog. Phylogenetic analysis suggested that Py-MSTN is an ancestral form of vertebrate MSTN and GDF11 and does not belong to other $TGF-{\beta}$ family members. Molecular modeling showed that Py-MSTN exhibits a similar tertiary structure to mammalian BMP7, a member of $TGF-{\beta}$ family. In addition, the amino acid residues which contact extracellular domain of the receptor were relavively conserved. Given these results, we propose that Py-MSTN is a functionally active member of the $TGF-{\beta}$ family and is involved In muscle growth and regulation.

• Fisheries and Aquatic Sciences
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• v.12 no.2
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• pp.138-151
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• 2009

We quantitatively investigated compositions of fish and invertebrate bycatch in Korean shrimp fisheries. We sampled shrimp trawl bycatch from 48 commercial trawls over 1 year. These samples contained 108 taxa from 50 families, with 60 fish taxa contributing 51.2% of the total biomass and 48 invertebrate taxa 48.8%. However, 86.32% of the total individual organism density comprised invertebrates, while individual fishes made up the remainder. Within the bycatch, two fish species varied in population size structure by season, suggesting recruitment is seasonal in these taxa. Overall general catch characteristics (total bycatch biomass and organism density) varied significantly by season and tide, and a significant interaction effect was observed (season$\times$tide) on total density, but not on total biomass. The data collected will be used in designing a program of long-term bycatch monitoring.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.10a
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• pp.217-221
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• 2010

• Fisheries and Aquatic Sciences
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• v.20 no.11
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• pp.28.1-28.17
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• 2017

Members of the phylum Echinodermata, commonly known as echinoderms, are exclusively marine invertebrates. Among the Echinodermata, sea cucumber belongs to the family Holothuroidea. The sea cucumber Stichopus (Apostichous) japonicus (Selenka) is an invertebrate animal inhabiting the coastal sea around Korean, Japan, China, and Russia. Sea cucumber has a significant commercial value, because it contains valuable nutrients such as vitamins and minerals. They possess a number of distinctive biologically and pharmacologically important compounds. In particular, the body wall of sea cucumber is a major edible part. It consists of peptide, collagen, gelatin, polysaccharide, and saponin, which possess several biological activities such as anti-cancer, anti-coagulation, anti-oxidation, and anti-osteoclastogenesis. Furthermore, the regenerative capacity of sea cucumber makes it a medically important organism. This review presents the various biological activities and biomedical potential of sea cucumber S. japonicus.

• Journal of Ecology and Environment
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• v.37 no.4
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• pp.185-194
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• 2014

Seasonal monitoring was implemented to understand the influence of macrophyte bed structure on the composition and trophic interaction of aquatic organisms (algae, zooplankton, macro-invertebrate, and fish) in a shallow wetland (Upo Wetland, South Korea). Distinct division of the plant assemblage (reed zone and mixed plant zone) was observed. The reed zone was composed solely of Phragmites communis, whereas the mixed plant zone comprised a diverse macrophyte assemblage (Salvinia natans, Spirodela polyrhiza, Trapa japonica, Ceratophyllum demersum, and Hydrilla verticillata). Most of the aquatic organisms were more abundant in the mixed plant zone than in the reed zone, and this was positively associated with the seasonal development of macrophyte cover. Stable isotope analysis showed seasonal interactions among aquatic organisms. The majority of aquatic animal (zooplankton, Odonata, and Ephemeroptera) were dependent on epiphytic particulate organic matter (EPOM), and the dependence on EPOM gradually increased toward autumn. Interestingly, Lepomis macrochirus consumed Ephemeroptera and zooplankton in both macrophyte zones, but Micropterus salmoides depended on different food items in the reed zone and the mixed plant zone. Although, M. salmoides in the reed zone showed food utilization similar to L. macrochirus, it consumed Odonata or small L. macrochirus in the mixed plant zone. Based on these results, it appears that differences in the structure of the two macrophyte zones support different assemblages of aquatic organisms, strongly influencing the trophic interactions between the aquatic organisms.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.504-505
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• 2006

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.268-275
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• 2009

The survival and growth of marine benthic invertebrate larvae such as abalone depend on the nutritional value of micro algae. However, it is difficult to determine the dietary value of the many microalgal species used for food by benthic larvae. Therefore, we tested the benthic copepod, Tigriopus japonicus, which grazes microalgae on substrata in a manner similar to abalone larvae. It also has short generation time and is easy to rear which makes to be easier to examine the dietary value of each micro algal species. We measured the daily production of nauplii from gravid females of T. japonicus fed 26 microalgal species separately. Amino acid and fatty acid content of the micro algae and the copepod was also analyzed. The nauplii production of T. japonicus was the highest (10.7) when they were fed Navicula sp. (B-394) and the lowest (0.8) when they were fed Scrippsiella trochoidea. In Tetraselmis suecica the nauplii production was so high (8.2), which was not significantly different with the diatom group. We determined that Navicula sp. (B-394), Rhaphoneis sp. and T. suecica were good sources of food for T. japonicus. We suggest that a diet of with a mixture of these three micro algal species may be also good for invertebrate larvae such as abalone.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.913-919
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• 2015

In vertebrates, the vitamin D receptor (VDR), a member of the nuclear receptor superfamily, binds the biologically active ligand $1{\alpha},25-(OH)_2$-vitamin $D_3$ (1,25 $D_3$). Nearly all vertebrates, including Agnatha, possess a VDR with high ligand selectivity for 1,25 $D_3$ and related metabolites. Although a putative ancestral VDR gene is present in the genome of the chordate invertebrate Ciona intestinalis, the functional characteristics of marine invertebrate VDR are still obscure. To elucidate the ascidian Halocynthia roretzi VDR (HrVDR), we cloned full-length HrVDR cDNA and investigated the transcriptional activity of HrVDR in HEK293 cells. HrVDR consists of 1,680 nucleotides (559 amino acids [aa]), including a short N-terminal region (A/B domain; 26 aa), DNA-binding domain (C domain; 72 aa), hinge region (D domain; 272 aa), and C-terminal ligand-binding domain (E domain; 161 aa). The amino acid sequence identity of HrVDR was greatest to that of C. intestinalis VDR (56%). In the luciferase reporter assays, the transcriptional activity of HrVDR was not significantly increased by 1,25 $D_3$, whereas the farnesoid X receptor agonist GW4064 increased the transactivation of HrVDR. These results suggest the presence of a novel ligand for and a distinct ligand-binding domain in ascidian VDR.

• Development and Reproduction
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• v.25 no.4
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• pp.305-311
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• 2021

The oligonucleotides polymers (ON-polymers) were used producing a total of 110 loci unique to each clam population (LUECP) in group one and 132 in group two, respectively, varying in amount of DNA fragments (FRs) from greater than near 50 to a smaller quantity than 1,050 bp. The larger FR amounts (>1,050 bp) are not noticed in the two Scapharca subcrenata groups. The ON-polymer OPD-01 produced 33 LUECP, which were defining each group, almost 300 bp, 450 bp, and 500 bp, in the group one. The OPD-15 recognized 22 loci shared by the two clam populations (Loci shared by the two clam populations, LSTCP), a variety of FRs of sizes 300 bp that were equivalent in all specimens. The mean number of LUECP was varied and 1.2-fold greater in the shellfish group two than in the group one. Respecting mean bandsharing (BS) grade outcomes, entities in the shellfish group one (0.779±0.011) had a little higher BS grades than did entities from the group two (0.756±0.009) (p<0.05). The entities of the shellfish group one are not tightly gathered with other entities of the group two. The genetic distance (GD) (0.422) of this invertebrate (SUBCRENATA 02 and 01) is 7.41-fold hereditarily distinct to the GD (0.057) of the other invertebrate (SUBCRENATA 22 and 19). The polar dendrogram (PDG) procured by the five ON-polymers underlines two characteristic groups.