• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.3
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• pp.396-404
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• 2015

Morotoge shrimp Pandalopsis japonica is caught by pot and others in the eastern coastal waters of Korea. Comparative fishing experiments were carried out in the eastern coast of Korea, using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3 mm) in order to estimate the mesh selectivity of the pot for the morotoge shrimp, Pandalopsis japonica. The SELECT (Share Each Length's Catch Total) analysis method was applied to the catch data. The master selection curve of the pot for the shrimp was estimated to be s(R) = exp(15.770R-10.573)/[1+exp(15.770R-10.753)], where R is the ratio of carapace length to mesh size. From the selection curves, the carapace lengths of 50% retention were 11.6, 17.0, 23.9, and 34.1 mm for 17, 25, 35, and 50 mm mesh-size pot, respectively. It means that the pots of larger mesh size allow more shrimp of small size to escape.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.5
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• pp.562-566
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• 2014

Larvae of pandalid shrimp Pandalopsis japonica are benthic, and may prefer bottom to planktonic food items. Three diets, enriched Artemia meta-nauplii (AR), clam meat (CM), and crumbled shrimp (CD), were evaluated as food for early larvae in terms of biometric growth R:D ratios. Larvae fed AR and CM had significantly greater total length and dry weight than did larvae fed CD (P<0.05). Survival was significantly greater in larvae fed CM than in those fed AR and CD (P<0.05). R:D ratios were also significantly higher in larvae fed AR and CM than in those fed CD (P<0.05). Planktonic Artemia meta-nauplii containing high levels of fatty acids and amino acids were not suitable for either normal somatic growth or survival at early benthic larval stages. Furthermore, it is necessary to determine the optimal feeding duration to increase digestibility of AD. Thus, we propose that clam meat is the best diet for pandalid shrimp larvae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.807-812
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• 2013

The energy budget of the larvae of pandalid shrimp, Pandalopsis japonica, reared in the laboratory from zoea to post-larva was investigated. Energy used during the growth of the shrimp larvae was calculated daily for feeding, growth, molting, and metabolism. The total energy used was 16.2 J for the entire larval stage. Molting energy loss was estimated at a total 1.03 J. Energy used for respiration was estimated at a total of 1.85 J. The intake energy by feeding reached a total of 77.69 J. The total sum of energies used by excretion and egestion was 58.61 J. Larvae assimilated 24.57% of ingested food and used 84.91% for somatic growth. The gross growth efficiency ($K_1$) was 22.19% for the entire larval stage, and the net growth efficiency ($K_2$) was 90.31%. Maintenance costs were estimated at 9.69% of assimilated energy for the entire larval stage.

• Proceedings of the Korean Aquaculture Society Conference
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• 2002.08a
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• pp.210-211
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• 2002

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1997.06a
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• pp.193-194
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• 1997

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.338-339
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• 2002

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.22-30
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• 2011

Vitellogenin (Vg) is the precursor of vitellin (Vn), which is the major yolk protein in nearly all oviparous species, including fish, amphibians, reptiles, and most invertebrates. It is one of the most important factors during reproduction, and numerous studies have shown that Vg genes are markers of the reproductive cycle and effecter genes induced by endocrine-disrupting chemicals (EDCs). Previously, we isolated two distinct cDNAs encoding vitellogenin homologs Pj-Vg1 and Pj-Vg2 from Pandalus shrimp Pandalopsis japonica. In this study, full-length genomic sequences of Pj-Vg1 and Pj-Vg2 were determined using a PCR-based genome walking strategy. Isolated Pj-Vg1 and Pj-Vg2 genes were 11,910 and 11,850 bp long, respectively. Both Pj-Vg genes had 15 exons and 14 introns, and the splicing sites were also the same, suggesting that they arose via gene duplication. The similar structural characteristics of decapod Vg genes suggest that they are all orthologs that evolved from the same ancestral gene. Analysis of Pj-Vg1 and Pj-Vg2 expression revealed that the relative copy numbers of Pj-Vg1 and Pj-Vg2 were similar in the hepatopancreas, whereas Pj-Vg2 transcripts were also detected in the ovary. Expression of both Pj-Vg genes was induced in hepatopancreas of mature individuals, whereas only Pj-Vg2 transcripts were upregulated in the ovaries from mature animals, suggesting that both Pj-Vgs are important for oocyte development. A strong positive correlation was found between Pj-Vg1 and Pj-Vg2 transcripts in the same individual, indicating they are under the same control mechanisms. Additionally, a positive correlation was found between ovarian and hepatopancreatic Pj-Vg2 transcripts, suggesting that its dual expression is regulated by similar physiological conditions. Knowledge of the similarities and differences between the two vitellogenin-like genes, Pj-Vg1 and Pj-Vg2, would help us to understand their roles in reproduction and other physiological effects.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2005.05a
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• pp.83-85
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• 2005

• Fisheries and Aquatic Sciences
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• v.17 no.4
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• pp.421-425
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• 2014

The antioxidant and cholinesterase inhibitory activities of the acetone and dichloromethane ($CH_2Cl_2$) extracts of the by-products (heads, shells, and tails) of Pandalus borealis, Pandalus hypsinotus, and Pandalopsis japonica belonging to the family Pandalidae were investigated and their bioactivities were compared. The antioxidant and cholinesterase inhibitory activities of the organic solvent extracts of three shrimp by-products were evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-Azino-bis[3-ethylbenzothiazoline-6-sulfonic acid] ($ABTS^+$) radical scavenging activities, reducing power and xanthine oxidase (XO) inhibitory activity assays and Ellman's colorimetric method. The extracts of P. hypsinotus exhibited the highest antioxidant and cholinesterase inhibitory activities. The acetone extracts showed more potent activities toward antioxidant and cholinesterase inhibition compared with the $CH_2Cl_2$ extracts. Furthermore, the total carotenoid contents of the acetone extracts were higher than those of the $CH_2Cl_2$ extracts. Thus, the carotenoid contents may affect antioxidant and cholinesterase inhibition. Our results suggest that the shrimp by-products could act as a nutraceutical agent to prevent oxidative stress and Alzheimer's disease.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.4
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• pp.368-376
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• 2013

Fishing experiments were carried out in the adjacent sea of Yeongil Bay, the eastern cost of Korea from 2003 to 2004 using the dome-shaped pots with different five mesh sizes (17.1, 24.8, 35.3, 39.8, and 48.3mm) in order to determine the size selectivity of pots for the whelk, Buccinum opisthoplectum. The catch species were composed of Buccinum opisthoplectum (45.4%), Buccinum striatissimum (30.1%), Pandalopsis japonica (9.3%), Chionoecetes opilio (8.9%), and so on. The shell height (l) of Buccinum opisthoplectum caught in the experimental fishing pots was measured. The SELECT (Share Each Length's Catch Total) analysis method was applied with fishing data to obtain master selection curve. The model with the estimated split parameter was found to fit the catch data best. The master selection curve was estimated to be s (R)〓exp (7.833R-10.871)/[1 + exp (7.833R-10.871], where R is the ratio of shell height to mesh size. The relative shell length for 50% retention was 1.388, and the selection range was 0.281. It means that the pots of larger mesh size allow more whelks of small size to escape.