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open access
메뉴This study surveyed endangered species, Lamprotula coreana, growth and survival rate by indoor . reared (IDR) and outdoor . reared (ODR). We measured shell length, height, width, weight every month and surveyed water condition everyday from February to November 2015. To assess the growth, calculate growth rate (GR), daily growth rate (DGR), specific growth rate (SGR), weight gain (WG), daily weight gain (DWG), specific weight gain (SWG). As a result, Initial shell length is 71.00 ± 3.37 mm IDR and 88.53 ± 5.63 mm ODR. Final shell length is 78.54 ± 3.60 IDR mm and 92.53 ± 4.92 mm ODR. Initial total weight is 103.67 ± 17.99 g IDR and 203.78 ± 30.61 g ODR. Final total weight is 138.43 ± 19.79 g IDR and 232.95 ± 31.82 g ODR. GR, DGR, SGR, WG, DWG, SWG are significantly different with IDR and ODR (P < 0.05). IDR is significantly higher than ODR and I presume it is because of the fed and water temperature. SR is over 92% for both of them and it is possible to reared indoor and outdoor. Recently, river construction work and environmental change have caused negative impact on the distribution of L. coreana. The result of this study would provide fundamental data for management and species preservation of L. coreana.
In order to determine optimal larval rearing conditions, the growth and the survival (%) of larvae on rearing conditions (water temperature, salinity, rearing density) and live food for keen's gaper Tresus keenae were investigated. Live food was used by cultured three microalgal species (Isochrysis galbana, Chaetoceros gracilis, Tetraselmis tetrathele) and microalgae concentrates (Shellfish diet 1800®, Reed Mariculture Inc., San Jose, CA, USA). The fastest growth was observed at 25℃ and the survival rate was over 30% at 15℃ and 20℃. The fastest growth and high survival of larvae were observed at 30 psu. The rearing density of larvae showed the fastest growth and the highest survival at 5 inds./mL. In the optimum rearing conditions of larvae the water temperature was 20℃, salinity was 30-35 psu and the rearing density of larvae was below 5 inds./mL. Larvae fed on different concentrations of cultured microalgae showed the fastest growth at 3 × 104 cells/mL/day and the highest survival at 1 × 104 cells/mL/day. Larvae fed on cultured microalgal species and microalgae concentrates showed the fastest growth and the highest survival at CM100 (cultured microalgae 100%) but the late growth at IA100 (instant algae 100%). Larvae fed on different feeding concentrations of microalgae concentrates showed the fastest growth at 2 × 104 cells/mL/day and the high survival at 1 × 104 cells/mL/day. Thus, larvae showed the fast growth and the high survival fed on microalgae concentrates or cultured microalgal species mixed instant algae. The optimal concentration of microalgae concentrates was 1 × 104 － 2 × 104 cells/mL/day for elevating the growth and the survival for larval rearing of T. keenae.
The Organic matter and trace metal contents and trace metal contents of sediments and their pollution levels at 9 stations were investigated in order to characterize sediment environment characteristics in the Geojeman Bay shellfish farming waters. The grain size of the surrounding sediments of the Geojeman Bay shellfish farm was in the order of mud in all samples. Clay contents ranged from 20.75-28.14% (24.15%), and the silt content 71.87-79.24% (75.85%). Ignition loss (IL) was in the range of 7.7-9.9% (9.2 ± 0.64%). Chemical oxygen demand (COD) was in the range of 17.9-26.6 mgO2/g (21.6 ± 2.52 mgO2/g). There is a possibility of contamination of organic matter. The concentrations of trace metals (As, Cd, Cr, Cu, Ni, Pb and Zn) in sediments of Geojeman Bay were analyzed. The contamination level of trace metals was evaluated by the concentration of each element. Cu exceeded the marine environment standard of threshold effects level. As, Cd, Cr, Ni, and Pb were below marine environment standard of threshold effects level in all study area. The pollution load index (PLI) for evaluating the total pollution level of trace metals was 1.1-1.4 (1.3), all study area and showed relatively high pollution at the entrance of the bay. The ecosystem risk index (ERI), was 98.8-131.14 (114.7), which was a moderate risk to some extent at most study area. Cr, Pb, and Zn were unpolluted, Cu and Cd were moderately polluted from nonpolished, and As was a medium pollution level. Moderately polluted.
We have studied the systematic monitoring method and construction of tidal flat environment. Surface sediment and sea water samples from the Gomso and Geunso bay of intertidal areas at cultured clams were analyzed for geochemical characteristics and physiochemical parameters. The geochemical characteristics(Chemical Oxygen Demand(COD) ranged from 4 to 8 mg/g-dry wt, Ignition Loss(IL), acid Acid Volatile Sulfide(AVS), Enrichment Factor(Ef), Accumulation Rate(Igeo), C/N ratio and C/S ratio) were measured to estimate the connection of between the contents of inorganic elements in surface sediments of research area. The mean grain size of sediments for research area were different at the ratio of silt and clay. The deposit pore-water of sediments were analyzed the distribution of nutrients at a certain depth profile using the pore-water extraction apparatus. On a wet weight bsais, the concentration of ΣBenzo[α]pyrene ranged frome 0.02 ng/g to 5.61 ng/g and the concentration of toxicity equivalent factor (TEF) for ΣBenzo[α]pyrene ranged frome 0.12 ng/g to 6.51 ng/g. Ef value and Igeo of the metals proved that environmental characteristics can be classified as heavily to moderately polluted. The C/S, C/N ratio were revealed that research area had anoxic or sub-anoxic bottom conditions, respectively. The research areas of cultured clams were effected by the various environmental conditions.
Hox genes are expressed along the anterior-posterior body axis in a collinear fashion in the majority of bilaterians. Contrary to polyplacophorans, gastropods including abalone deviate from this pattern by expressing Hox genes in distinct morphological structures and not in a staggered fashion. However, the molecular developmental understandings remain unknown. In the present study, we isolated DNA sequence of Hox gene from genome database and investigated its mRNA expression in early developmental stages of abalone, Haliotis discus hannai. The H. discus hannai Hox gene (HDH-HoxA2) showed 36% and 37% amino acid identities with with HoxA2 of Crassostrea gigas and Mixuhopecten yessoensis, respectively. The 62 amino acids sequence of homeodomain was conserved well in HDH-HoxA2. The qRT-PCR detected HDH-HoxA2 at the first day after hatching (trocophore larvae stage), but the expression of HDH-HoxA2 mRNA decreased after two days post-hatching. The present study is the first to report on the molecular cloning, characterization and expression analysis of Hox gene in H. discus hannai. The results might provide new insights into the regulation of early developmental stages of abalone.
It is known that severe infestation of polychaetes with abalone shells can cause mortality and affect productivity. In order to obtain accurate data on polychaete infestations, we surveyed the infection rate of polychaetes in the abalone, Haliotis discus hannai cage farms located in Wando area. The survey included changes in infestation rates for three years, monthly and seasonal changes in infestation rates and infestation rates in the spawning field. The range of infestation rate of polychaetes against abalone for 3 years was 23.8-52.8%. In general, infestation rate increased rapidly around high temperature (around August) and peaked in autumn. The mean infestation rate of the polychaetes of the onshore farms producing abalone was 5.4%. Therefore, the rate of polydorides infestation in abalone farms in Wando-gun increased during the period of rising water temperature, and it is considered that the infestations that occur during the production of young shell may be affected.
The PANM Database (Protostome DB) was constructed for the first in the year 2015. The aim of the construction was to provide a public platform for researchers to efficiently annotate the next-generation sequencing (NGS) data arising out of genome sequencing projects of species belonging to Arthropoda, Mollusca, and Nematoda (Protostome group). The web-based interface has paramount importance in improving the process of sequencing data with a greater number of noteworthy hits. In the subsequent year, we released an update to the database (PANM-DB v1.0) that contained twice the number of protein sequences (7,571,246) as compared to the original database and the inclusion of Cephalopod sequences. We now release the third database update (PANM-DB v3) with the incorporation of 11,615,243 protein sequences. The size of PANM-DB v3 is smaller, only 6% of NCBI nr database, and significantly reduces the NGS data annotation time. Like the previous versions of the database, PANM-DB v3 is freely downloadable from http://panm.sch.ac.kr/ for local BLAST analysis.
Three unrecorded sacoglossan species of Hermaea noto (Baba, 1959), Ercolania boodleae (Baba, 1938), and Elysia trisinuata Baba, 1949 were collected from South Sea of Korea and redescribed with pictures.
