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ISSN : 1225-3480
The aim of this study was to provide biological basic information of Haliotis spp. hybrid using by reproductive biomarkers. The sex ratio showed high proportion of the female in three hybrids (H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus discus ♂ (1:0.1), H. discus hannai ♀ <TEX>${\times}$</TEX> H. madaka ♂ (1:0.4) and H. discus discus ♀ <TEX>${\times}$</TEX> H. discus hannai ♂ (1:0.5)), but in two hybrids (H. discus discus ♀ <TEX>${\times}$</TEX> H. gigantea ♂ (1:1.6) and H. discus discus ♀ <TEX>${\times}$</TEX> H. madaka ♂ (1:1.3)) the male. Sexual maturation was observed in two hybrids (H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus discus ♂ and H. discus discus ♀ <TEX>${\times}$</TEX> H. discus hannai ♂). The gonad index (GI) showed a high level in the two hybrids with observed sexual maturation than the three hybrids with not observed. The condition index (CI) and the meat weight rate (MWR) were not show significant difference.
This study interested on spawning and early embryo development in surf clam, Tresus keenae. For spawning induction, we performed natural spawning, physical stimulus (temperature, air dry), freshwater stimulus and chemical stimulus (sperm suspension). In addition, the sperm amounts were differently treated during artificial insemination and were investigated optimal amount of sperm through fertilization rate and hatching rate. The effects of water temperature and salinity on early embryo development were also investigated. Result that, the physical stimulation method was the most effective method with 35% efficiency in inducing spawning. The fertilization rate and hatching rate were best when <TEX>$50{\times}10^4inds./egg$</TEX> sperm were used for artificial insemination. The effects of water temperature and salinity on reaction velocity of embryogenesis were investigated. The fast velocity of embryogenesis had the water temperature was higher and salinity concentration was close to natural condition.
In order to figure out the characteristic of the occurrence of manila clam seeds and its inhabited environment in the mid-south of West coast, investigated at 19 manila clam beds on April and August, 2013. Water environment were shown to be changed depend on time of investigation rather than geographical effect. Sediment quality were under reference value which means it is uncontaminated. Regarding the sedimentary environment, sedimentary facies of the surface deposit were as various as eight, with a higher tendency of coarse-grained deposit in the contents of gravel, sand, silt, and clay. The average exposure time of the manila clam farms was 1 hour and 55 minutes. At the 10-20 mm habitat density of seed clams, no seed clams were harvested in April at Dangmi, Jukyo, Rahang, and Beopsan, which showed a typical phenomenon where seed clams grew and increased in number in August. On the contrary, Doseong, Wangsan, and Daecheon showed the opposite results where more seed clams were harvested in April than August, presumably because the habitat density of seed clams was too high in the previous year to delay growth. More seed clams developed in the sedimentary environments with coarse sizes of average deposit particles, mixed with other particles of various sizes.
This study conducted hybridizations between cold water Haliotis discus hannai and warm water Haliotis discus discus to produce both hybrid and pure hatchery stock and then compared growth and survival between the hybrid and pure seeds which were reared in indoor tanks and then seawater cages. A 250 day long culture in indoor tanks showed the highest growth in the hybrid H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus discus ♂, which was followed by the pure H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus hannai ♂. After the 250 day long culture in tanks, seeds with about 34 mm shell length were selected from the tanks and transferred to seawater cages to be reared for another 950 days. The sea cage culture also showed the highest growth in the hybrid H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus discus ♂ like indoor culture. Survival rate of the pure H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus hannai ♂, the hybrid H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus discus ♂, the hybrid H. discus discus ♀ <TEX>${\times}$</TEX> H. discus hannai ♂, and the pure H. discus discus ♀ <TEX>${</TEX><TEX>\times}$</TEX> H. discus discus ♂ during the 950 day cage culture was <TEX>$38.63{\pm}0.02%$</TEX>, <TEX>$39.63{\pm}0.01%$</TEX>, <TEX>$31.25{\pm}0.02%$</TEX> and <TEX>$24.25{\pm}0.05%$</TEX>, respectively, indicating the hybrid H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus discus ♂ having the highest Survival rate. In conclusion, the comparison of growth and mortality between the hybrid and pure seeds reared in land-based tanks and seawater cages demonstrated that the hybrid H. discus hannai ♀ <TEX>${\times}$</TEX> H. discus discus ♂ performed the best.
Abalone is economically important marine resources for fisheries and aquaculture industries worldwide. The climate changes cause the mass mortality of farmed abalone and have led to the economic loss of fisheries and aquaculture industries in Korea. In order to find genes which are involved in physiological response to temperature stress, we have performed sequencing of transcriptome after thermal stimulation. The heat-shock response is elicited by exposure of cells to thermal and chemical stress and induces activation of Hsp70. Heat shock binding protein 1 (HspBP1) was originally identified as a protein that interacts with Hsp70 and inhibits its chaperone. In this study, molecular characterization and expression of HspBP1, named abHspBP1, were studied to understand the mechanism of heat shock response of the pacific abalone (Haliotis discus hannai) under thermal stresses. The full-length cDNA of abHspBP1 was of 981 bp, encoding a protein of 326 aa. Multiple alignments and phylogenetic analysis with the deduced amino acid of abHspBP1 showed homology with Mizuhopectenyessoensis HspBP1. Reverse transcription PCR analysis indicated that the abHspBP1 mRNA in the hemocyte and gill was drastically increased at <TEX>$30^{\circ}C$</TEX>. The expression of Hsp70 in the hemocytes and gills was drastically increased at <TEX>$30^{\circ}C$</TEX>. Our present study for the first time reported the identification, molecular cloning, characterization and tissue expression analysis of HspBP1 in Haliotis discus hannai. The results of this study might provide new insights into the regulation of heat shock response in this species.
This study was performed to identify rapidly Haliotis gigantea using polymerase chain reaction with species-specific primers. Around 680 bp of the mitochondrial ND5 gene region from four Haliotis species were aligned and species-specific forward primer was designed based on the single nucleotide polymorphism (SNP) from H. gigantea. The optimal PCR conditions were selected by cross reactivity using gradient PCR method from <TEX>$55^{\circ}C$</TEX> to <TEX>$66^{\circ}C$</TEX>. Species-specific PCR (SS-PCR) amplification reactions with two pairs of primers were performed for a five specimens of Haliotis species. SS-PCR leads to a species specific amplification of a 1,006 bp fragment in H. discus hannai, H. discus discus, H. madaka and 786 bp in H. gigantea, respectively. The two different sizes of each PCR products can be quickly and easily detected by single gel electrophoresis. The sensitivity of the SS-PCR was up to <TEX>$1ng/{\mu}l$</TEX> DNA as a starting concentration in H. gigantea tested. Therefore SS-PCR technique with species-specific primer based on SNP could be a powerful tool for discrimination of H. gigantean and can contribute to the prevention of falsified labeling of this species.
Metallothioneins (MT) are cysteine-rich small proteins known for their high affinity binding to metal ions. MT confers cytoprotection against oxidative stress and acts as an efficient modulator of immunity and infection. There have been ever-increasing reports on the function of MT in environmental monitoring programmes. Lately, MT has been studied as a biomarker towards the taxonomic clustering of various species, including the molluscans. The Korean endemic land snail, Aegista chejuensis is native to Jeju Island and South coastal regions of Korea. Functional genomics information for the species is limited, although the Illumina-based DNAseq and transcriptome information are registered with the Sequence Read Archive (SRA) of National Center for Biotechnology Information (NCBI). While annotating the ORF-sensitive unigenes from the transcriptome, a MT sequence comprising of 288 bp coding region and 96 amino acid residues translatable protein was deciphered. In silico analysis using ClustalX and the MEGA7 program grouped A. chejuensis under the Stylommatophora clade of eupulmonate mollusk families. The study was able to confirm the evolutionary position of the species and established the MT sequence as a candidate for taxonomic classification of the species.
Tide pools in the rocky intertidal of Jeju Island are characterized by a rich molluscan biodiversity, often associated with macro algae; however, few studies have reported on the unique algae-mollusk association in tide pools in Jeju Island. In May 2012, we collected mollusk species associated with the coralline algae Corallina confusa Yendo, 1902 from a tide pool at Hamo beach on the south-west coast of Jeju Island. A total of 24 species associated with the coralline algae were identified, including one chiton in the Mopaliidae, 4 bivalves, and 19 gastropods. Most of the molluscs isolated from the coralline algae were juvenile and sub-adults, suggesting that C. confusa clusters in tide pools are utilized as a shelter or source of food for grazing gastropods.
We report the Korean marine gastropods which were collected form six localities in Korean sea waters from May 1995 to February 2007. Among them, 11 species (Lottia tenuisculpta, Coccopigya punctoradiata, Lirularia pygmaea, Eatonina kitanagato, Assiminea estuarina, Assiminea hiradoensis, Teinostoma radiatum, Sticteulima amamiensis, Proterato pura, Bittium alutaceum, Cerithidium perparvulum) are redescribed with pictures.
