• Title/Summary/Keyword: Larval growth

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On the Early Life History of Gunnel (Enedrias fangi) (흰베도라치(Enedrias fangi)의 초기생활사에 관하여)

  • Yoo, Jae-Myung; Kim, Woong-Seo; Kim, Sung;Lee, Eun-Kyung
    • Korean Journal of Ichthyology
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    • v.7 no.1
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    • pp.25-32
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    • 1995
  • The larval fish, which had been previously identified or classified as Enedrias (Pholis) nebulosus, Enedrias spp., Pholis taczanowskii, and unidentified species belonging to Protosalanginae, were revealed as that of a gunnel, Enedrias fangi. This species has been known as a cold water species mainly caught in the Yellow Sea. Larval E. fangi showed peak abundances in the coastal waters off Chonlla Province in March, Chungnam Province in April, and Kyunggi Province in May and June. The primary spawning season of E. fangi seemed to be winter (November to January), and the eggs hatched after 60 days from spawning. The average growth rate of larval fish was about 0.33mm/day. The larval fish of 40mm in body length began to move to the bottom, and stayed in the bottom cold water mass when their body length was greater than 60-70mm. The average annual catches of larval E. fangi from 1985 to 1991 were 5,000M/T in the Yellow Sea, which were more than 99 % of the total gunnel catches around Korean waters. The peak season of catches was from March or April to July in Chungnam Province, and from May to July in Kyunggi Province.

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Effect of Live Food and Water Temperature on Larval Survival of Red Spotted Grouper, Epinephelus akaara (먹이생물과 수온이 붉바리 자어의 생존에 미치는 영향)

  • 이창규;허성범
    • Journal of Aquaculture
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    • v.11 no.4
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    • pp.565-572
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    • 1998
  • Survival rate of larval red spotted grouper, Epinephelus akaara is very low, because mouth size of the larvae is too small to eat normal sizes of rotifers. In order to enhance larval survival, optimal culture conditions for larvae using different live foods and water temperatures were studied. Bigger live food produced larger size of rotifer, when the rotifer was cultured with three different live foods such as Tetraselmis tetrathele, marine Chlorella and Nannochloris oculata. Also, the size of rotifer produced was temperature-dependent showing that higher water temperature induced smaller rotifer. Survial rate of the larvae increased with the increase of water temperature up to $29{\circ}C$. Also, higher larval survials were found at the food density of 15 to 20 individuals per milliliter. The larvae fed L-type or small individuals of L-type rotifer died all within a week, although the larvae fed S-type or small individuals of S-type one survived successfully during this period. The size of small individuals of S-type rotifer collected through fine net became larger in a few hours within larval culture tank. Survival rate of grouper larvae with initial stocking density of 40 thousands in 6-ton concrete tank was 6.3% in 10 days and 0.2% in 53 days after hatching, respectively. Total length of the larvae reached around 29.5 mm in 53days after hatching.

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A Study of Ecotoxicity Test for Byproducts of Ozone in the Ballast Water Treatment System with Ozonation

  • Park, Sung-Jin;Ha, Shin-Young;Kim, In-Soo
    • Journal of Navigation and Port Research
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    • v.35 no.9
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    • pp.741-747
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    • 2011
  • Ecological toxicity testing of the whole-effluent from the ozone ballast water treatment system was conducted as specified in the quality assurance project plans (QAPP). The growth inhibition test with microalgae, acute aquatic toxicity test with the Rotifer reproduction, toxicity test (or population growth) with the Rotifer, survival and growth toxicity test with larval fish and sediment toxicity test with amphipod were carried out to evaluate ecological toxicity on the movile test barge.

Effects of the Insect Growth Regulator Dimilin on Larval Development of Hemigrapsus sanguineus (Crustacea, Brachyura) Reared in the Laboratory (무늬발게 幼生에 對한 Dimilin 의 致死 影響)

  • Kim, Chang Hyun
    • The Korean Journal of Ecology
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    • v.13 no.1
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    • pp.19-24
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    • 1990
  • The effects of insect growth regulator Dimilin which interfere with the synthesis of chitin in the cuticle of insect larvae were investigated at various concentrations using the crab larvae of Hemigrapsus sanguineus. The larvae were cultured at control, 0.5, 1, 5 and 10 $\mu g$ Dimilin solutions and three replicate experiments were carried out to give correct analysis. Significant differences in percent mortality have occurred between control and 10$\mu g$ when the larvae were exposed to Dimilin whereas no differences were found between 5 and 10$\mu g$ Dimilin concentrations. If lethal concentration is defined as concentration at which less than 10 percent of crab larvae reach to the last zoeal stage from hatching it can be concluded that insect growth regulator Dimilin is lethal to the larvae of Hemigrapsus sanguineus at 5 and 10$\mu g$ Dimilin.

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Neuropeptides and Neuroactive Substance in the Bembyx mori Brain: Allatotropin Gene and Localization, Neuronal Growth by BDNF, and Apoptosis by Edysone

  • Lee, Bong-Hee
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • 2003.10a
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    • pp.13-18
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    • 2003
  • Allatotropin is a 13-residue amidated neuropeptide isolated from pharate adult heads of the tobacco hornworm, Manduca serta and strongly stimulates biosynthesis of juvenile hormones in adults, but not larval, lepidopteran corpora allata. From a Bombyx mori midgut cDNA library, a cDNA that encodes a 130-amino-acid polypeptide containing M. sexta allatotropin sequence was isolated. The B. mori allatotropin cDNA consists of 1196 nucleotides. (omitted)

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Sexual Maturation of the Top Shell, Omphalius rusticus (Gastropoda: Trochidae), on the Western Coast of Korea

  • Lee, Ju-Ha
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2000.10a
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    • pp.244-245
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    • 2000
  • The top shell, Omphalius rusticus (Gastropoda: Trochidae), is marine mollusk inhabiting underneath a rock in the intertidal zone of the coasts of Korea and Japan, and it is one of the edible gastropods. This species is a herbivorous animal. Up to now, there have been some reports on the Trochidae: aspects of classification, spawning periodicity, production, growth and size-frequency distribution of living populations, feeding, reproductive cycle, and induction of larval metamorphosis. (omitted)

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Identification of Antioxidative Component of Marine Microalgae

  • Kim, Se-Kwon;Baek, Ho-Chul;Lee, Sang-Hun
    • Proceedings of the Korean Society of Fisheries Technology Conference
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    • 2001.05a
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    • pp.144-145
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    • 2001
  • Marine microalgae are used extensively in mariculture as food for marine animals, in particular larval and juvenile molluscs, crustaceans and fish. A wide range of microalgae has been tested, because not all species are equally successful in supporting growth of a particular animal. In addition, bioactivities of marine microalgae are recently investigated for the effective exploitation of unutilized marine resources. (omitted)

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Expression of Cell Proliferation-Related PCNA and E2F Genes in Drosophila Gut and Inhibitory Effect of Nitric Oxide

  • Choi, Na-Hyun;Kim, Young-Shin;Hwang, Mi-Sun;Nam, Hyuck-Jin;Kim, Nam-Deuk;Chung, Hae-Young;Yoo, Mi-Ae
    • Animal cells and systems
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    • v.5 no.1
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    • pp.59-64
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    • 2001
  • To understand the late gut development and differentiation, identification and characterization of target genes of homeotic genes involved in gut development are required. We have previously reported that homeodomain proteins can regulate expression of the cell proliferation-related genes. We investigated here the expression of the Drosophila proliferating cell nuclear antigen(PCNA) and E2F(dE2F) genes in larval and adult guts using transgenic flies bearing lacz reporter genes. Both PCNA and dE2F genes were expressed strongly in whole regions of the larval and adult guts including the esophagus, proventriculus, midgut and hindgut, showing higher expression in foregut and hindgut imaginal rings of larva. Nitric Oxide(NO) has been known to be involved in cell proliferation and tumor growth and also to have an antiproliferative activity. Therefore, we also investigated effects of NO on the expression of PCNA and dE2F genes in gut through analyses of lacz reporter expression level in the SNP (NO donor)-treated larval guts. Expressions of both PCNA and dE2F were greatly declined by SNP. The inhibitory effect of NO was shown in whole regions of the gut, especially in hindgut, while the internal region of proventriculus, esophagus, foregut imaginal ring and hindgut imaginal ring was resistant. Our results suggest that this inhibitory effect may be related with the antiproliferative activity of NO.

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Detection of the expression of a Bombyx mori Atypical Protein Kinase C in BmPLV-Infected Larval Midgut

  • Cao, Jian;He, Yuanqing;Li, Guohui;Chen, Keping;Kong, Jie;Wang, Fenghua;Shi, Jing;Yao, Qin
    • International Journal of Industrial Entomology and Biomaterials
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    • v.22 no.2
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    • pp.59-64
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    • 2011
  • Protein kinase C (PKC) is involved in many cellular signaling pathways, it participates in many physiological processes, such as cell cycle, growth, proliferation, differentiation and apoptosis. To investigate the effect of PKC on the silkworm midgut tissue infection of Bombyx mori parvo-like virus (BmPLV), a B. mori atypical protein kinase C (BmaPKC) gene was cloned from larval midgut tissue, expressed in E. coli and purified. Additionally, the BmPLV susceptible silkworm strain and resistant silkworm strain were used to test the effect of the B. mori infection on BmPLV. The result showed that BmaPKC encodes a predicted 586 amino acid protein, which contains a C-terminal kinase domain and an N-terminal regulatory domain. The maximum expression amount of the soluble (His)6-tagged fusion protein was detected after 0.8 mmol/L IPTG was added and cultured at $21^{\circ}C$. The (His) 6-tagged fusion protein revealed about 73 kDa molecular weight which confirmed by western blot and mass spectrography. Furthermore BmaPKC protein were detected at 0-72 h post-infection in BmPLVinfected larval midgut tissue, western blot showed that as time went on, the expression of BmaPKC increased gradually in susceptible strain, the expression quantity on 72 h is 5 times of 0 h. However, in resistant strain, the expression quantity is slightly lower than susceptible strain. But no significant change in resistant strain was observed as time went on. The available data suggest that BmaPKC may involve in the regulation of BmPLV proliferation.