• Development and Reproduction
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• v.13 no.4
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• pp.341-351
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• 2009

The effects of serotonin (5-hydroxytryptamine, 5-HT), ecdysone (20-hydroxyecdysone, 20-E) and HCG (human chorionic gonadotropin) on the ovarian maturation of the fleshy shrimp, Fenneropenaeus chinensis were investigated. Adult female fleshy shrimps were injected with 5-HT ($5{\mu}g$/g body weight (BW) or $20{\mu}g$/g BW), 20-E ($5{\mu}g$/g BW, $10{\mu}g$/g BW or $20{\mu}g$/g BW) or HCG (5 IU/g BW or 10 IU/g BW) three times at 5-day intervals and were sacrificed 10 days after the last injection. The effects were compared against an intact control group and sham control group which received the injection of sterile saline solution as a vehicle. 20-E and HCG showed no effectiveness on ovarian maturation in fleshy shrimps. However flesh shrimp given 5-HT of $20{\mu}g$/g BW showed significant increase in gonadosomatic index (GSI) in early spring. The results suggest that treatment of 5-HT of $20{\mu}g$/g BW or more is useful approach for the nursery production of the fleshy shrimp, Fenneropenaeus chinensis aquaculture.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.27-31
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• 2005

Early larval growth for total length (TL) and body weight (BW) in flesh prawn (Fenneropenaeus chinensis) was studied from hatching to 25 days after hatching. Mean total length at nauplius and zoea stages was 0.21-0.39 mm and 0.62-1.03 mm, respectively. Mean total length of mysis stage grew from 1.28 mm (9 days after hatching) to 5.98 mm (21 days after hatching). The increase of body weight during experimental period showed step by step growth pattern due to metamorphosis of this species. The relationship between BW and TL from hatching to 25 days after hatching was BW = 2E-5TL/sup 4.1707/ (r²= 0.9746).

• Journal of Life Science
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• v.25 no.12
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• pp.1347-1353
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• 2015

The fleshy shrimp, Fenneropenaeus chinensis, is the family of Penaeidae and one of the most economically important marine culture species in Korea. However, its genetic characteristics have never been studied. In this study, a total of 240 wild F. chinensis individuals were collected from four locations as follows: Narodo (NRD, n = 60), Beopseongpo (BSP, n = 60), Chaesukpo (CSP, n = 60), and Cheonsuman (CSM, n = 60). Genetic variability and the relationships among four wild F. chinensis populations were analyzed using 13 newly developed microsatellite loci. Relatively high levels of genetic variability (mean allelic richness = 16.87; mean heterozygosity = 0.845) were found among localities. Among the 52 population loci, 13 showed significant deviation from the Hardy–Weinberg equilibrium. Neighbor-joining, principal coordinate, and molecular variance analyses revealed the presence of three subpopulations (NRD, CSM, BSP and CSP), which was consistent with clustering based on genetic distance. The mean observed heterozygosity values of the NRD, CSM, BSP, and CSP populations were 0.724, 0.821, 0.814, and 0.785 over all loci, respectively. These genetic variability and differentiation results of the four wild populations can be applied for future genetic improvement using selective breeding and to design suitable management guidelines for Korean F. chinensis culture.

• Journal of fish pathology
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• v.22 no.1
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• pp.15-21
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• 2009

White spot syndrome virus (WSSV) is a strong causative agent for high mortality in cultured and wild shrimps. From this study, the WSSV prevalence in marine organisms around shrimp farm as well as live feed-mediated transmission of WSSV to farmed shrimps were investigated. Based on nested-PCR method, WSSV was detected in wide array of marine organisms including Perinereis aibuhitensis (81.3% of prevalence rate, 13/16), Enedrias fangi (100%, 16/16), Ruditapes philippinarum (20%, 2/10), crab larvae (100%, 10/10), copepoda (30%, 3/10), Periophthalmus modestus (50%, 5/10), Pachygrapsus crassipes (10%, 1/10), Helice tridens (20%, 2/10) and Neomysis sp. (70%, 7/10). On the other hand, WSSV was not detected in Bullacta exarata, Uca arcuata, and Reishia clavigera. The percent prevalence of WSSV in wild shrimps, Fenneropenaeus chinensis was only 6%, but markedly increased up to 56% after a feeding trial using polychaete worms for one month, indicating that the live feed is one of significant carriers of WSSV to shrimps under practical farming conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.5
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• pp.688-695
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• 2015

The objective of this study was to investigate the effects of bio-floc system that is composed of effective microorganisms (EM) on the microbial composition and water qualities in rearing water and the growth of Chinese white shrimp, Fenneropenaeus chinensis. To investigate the microbial composition according to the bio-floc levels, the study was conducted at 100 and 150% of bio-floc after 5 and 10 days in bio-floc system. The results showed that total bacteria count (TBC) and the counts of Latobacillus sp., Bacillus sp. and Rhodobactor sp., were significantly decreased after 5 days in bio-floc system. To assess the growth of F. chinensis according to the concentrations of bio-floc, the study was conducted at the bio-floc concentrations; 0 (control), 60, 80, 100, 120 and 140% of the prepared bio-floc for 90 days. The growth factors such as daily length and weight gain were considerably increased at the concentrations of bio-floc 100, 120, and 140% after 90 days. As water quality indicators, the values of total-N, NH₄⁺-N and PO₄^--P were analyzed, and they were significantly decreased at 120 and 140% of bio-floc, compared to the control. The results demonstrated that combination of EM showed the synergic effect on removing N and P.

• Journal of Aquaculture
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• v.17 no.4
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• pp.235-239
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• 2004

Experiments were carried out to examine the effects of the different levels of oxygen, ammonia and hydrogen sulfide on survival, specific growth rate (SGR) and feed conversion ratio (FCR) of juvenile shrimp, Fenneropenaeus chinensis. Survival of the shrimp exposed to the hypoxia with $\leq$2.5 mg/L dissolved oxygen for 24 days were significantly affected. SGR and FCR of the shrimp exposed to$\leq$3.0 mg/L dissolved oxygen were significantly reduced than those of shrimp reared at 6.8 mg/L dissolved oxygen concentration. Survival of the shrimp exposed to $\geq$2.0 mg/L of ammonia levels for 24 days was significantly affected. Moreover, compared to the control group significant decrease of SGR and FCR of the shrimp has been observed with $\geq$1.0 mg/L and $\geq$0.5 mg/L of ammonia concentrations. In case of hydrogen sulfide, $\geq$0.5 mg/L was the critical level showed its significant negative effect on survival rate of shrimp exposed for 24 days. While, the group exposed with $\geq$0.07 mg/L and $\geq$0.05 mg/L hydrogen sulfide levels had a lower SGR and FCR values than did the control group in the same stipulated time of exposure.

• Journal of Microbiology and Biotechnology
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• v.21 no.11
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• pp.1109-1115
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• 2011

A highly sensitive and specific TaqMan real-time PCR was used to quantify hepatopancreatic parvovirus (HPV) type III infections in wild broodstocks and hatchery-reared postlarvae (PL) of Fenneropenaeus chinensis. Totals of 159 and 162 wild brooders from three locations were captured, and 140 and 180 PL were obtained from seven and six commercial hatcheries in 2007 and 2008, respectively. Among the three wild broodstock groups from 2007, only 1 group showed HPV infection and 3.2% of 159 brooders were positive for HPV infection. In 2008, HPV infections were observed from all three wild broodstock groups with $1.93{\times}10^4$ copies/mg tissue of pleopods. Of 162 brooders, 26.6% were positive for HPV infection. No PL from the two hatcheries collected in 2007 showed HPV infection, and PL from the rest of the five hatcheries had up to $1.74{\times}10^6$ copies/ng of DNA, and PL from three hatcheries showed HPV infections with over 1,000 copies/ng of DNA. The PL from all seven hatcheries collected in 2008 showed up to $2.10{\times}10^5$ HPV copies/ng of DNA. PL from two hatcheries showed less than 100 copies/ng of DNA, but PL from the rest of the hatcheries showed HPV infections with over 1,000 copies/ng of DNA. These results show that HPV type III is widely distributed in Korea in addition to previously reported HPV type I, and they can be effectively detected by type-specific realtime PCR.

• Journal of Microbiology and Biotechnology
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• v.11 no.3
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• pp.394-398
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• 2001

Because of the great concern over the possibility of contamination from the rod-shaped nuclear virus (PRDV) from Japan and white spot virus (WSSV) from Taiwan, most eggs used in Korean shrimp farms are currently obtained from local broodstock. In addition, the screening of imported broodstock for any viral presence at the National Fisheries Research and Development Institute is also mandatory. Nonetheless, massive mortality from white spot syndrome continues in Korea. In the present study, we present an improved PCR method to use tissue-extracted DNA instead of viral DNA extracted from a purified virus based on a sucrose density gradient, and produced results within 8 h. In 1998, this modified PCR method was able to detect that diseased Penaeus japonicus were infected within 8 h. In 1998, this modified PCR method was able to detect that diseased Penaeus japonicus were infected only with PRDV, while Fenneropenaeus chinensis were infected with both PRDV and WSSV. In 1999, PRDV and WSSV were detected in F. chinensis with signs of infection, but not with WSSV alone.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.1
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• pp.34-39
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• 2007

Penaeidins are members of a special family of antimicrobial peptides existing in several species of shrimp and play a crucial role in the immunological defense of shrimp. In this study, we isolated and characterized one EST clone (penaeidin) from cDNA library of fleshy prawn Fenneropenaeus chinensis hemocytes. Amino acids sequence comparison and phylogenetic analysis with other known penaeidins revealed that our clone was completely identical to F. chinensis Penaeidin 3-2 (Accession no. ABC33920), which composed of 71 amino acids with a putative signal peptide (1-19) and a cysteine-rich domain (C-terminal part). The expression and distribution of Penaeidin 3-2 transcripts in shrimp were detected in hemocytes, hepatopancreas, and muscles, and that Penaeidin 3-2 was constitutively expressed mainly in hemocytes. The artificial infection of white spot syndrome virus to F. chinensis resulted in Penaeidin 3-2 mRNA up-regulation in hemocytes, suggesting that the possible role of Penaeidin 3-2 in host defense system of F. chinensis.

• Journal of Marine Bioscience and Biotechnology
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• v.2 no.4
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• pp.224-229
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• 2007

Muscle tissue expresses many muscle-specific genes, including myostatin (also known as GDF8) that is a member of the transforming growth factor-beta superfamily. Myostatin (MSTN) negatively regulates mammalian skeletal muscle growth and development by inhibiting myoblast proliferation. Mice and cattle possessing mutant MSTN alleles display a 'double muscling' phenotype characterized by extreme skeletal muscle hypertrophy and/or hyperplasia. In this study, we first have characterized partial cDNA of a MSTN gene from the muscle tissue in the F. chinensis and examined its expression pattern in various tissues. The partial MSTN gene (GenBank accession number EU 131093) in the F. chinensis was 1134 bp, encoding for 377 amino acids that showed 63-93% amino acid similarity to other vertebrate MSTNs, containing a conserved proteolytic cleavage site (RXRR) and conserved cysteine residues in the C-terminus. Based on a RT-PCR, the MSTN gene was expressed in the all tissues of F. chinensis used in this study.