• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.4
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• pp.604-613
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• 2014

Community structures and species composition in benthic crustacean around Oryukdo of Busan was investigated using a SCUBA diving in 2011. A total 115 species, 51 families, and 4 taxa were collected during the sampling periods. Species were included 52 species in amphipoda, 49 in decapoda, 8 in isopoda and 6 in thoracica. On cluster analysis, the benthic crustacea community was classified into three groups based on the species composition: group A occurred in spring, group B in autumn and winter and group C in summer. Species composition in benthic crustacean corresponded with the water temperature.

• Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.7-13
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• 2006

Using biochemical methods, we determined the potential of local female shrimp populations as breeding stock to select the best adult prawns for improving larval production. As condition indexes, we selected total RNA, DNA, their ratio, and trypsin activity. The DNA content in the pleopods of each local population was similar, i.e., between $0.90{\pm}0.06\;and\;1.02{\pm}0.04(SE){\mu}g/mg$. In comparison, the RNA contents differed markedly between $2.00{\pm}0.09$ and $0.96{\pm}0.08\;{\mu}g/mg$. Therefore, the RNA/DNA (R/D) ratio in the pleopod could be used as a condition index because it represents a biochemical characteristic of the population. The mean pleopodal R/D ratio of the Goheung population was the highest at $2.52{\pm}0.19$, which indicated the best condition. Trypsin activity was influenced little by shrimp condition and more by the amount of food ingested. The gonadosomatic index (GSI) and R/D ratio in the gonads provided offsetting information about the instantaneous gonad maturity. The Goheung population had the highest instantaneous GSI, despite some spawning. Based on the condition indexes and time of gonad maturation, the Goheung shrimp population is suitable for use as breeding stock.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.1
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• pp.20-28
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• 2005

Species composition and seasonal variation of decapod crustacean assemblage in Hampyeong Bay, Korea were examined. Sampling was monthly made by a shrimp trawl between March 2003 to February 2004. A total of 39 species of 20 families were collected. Of these, Latreutes planirostris, Palaemon gravieri, Parapenaeopsis tenella, Exopalaemon carinicauda, Charybdis japonica, Trachysalambria curvirostris and Palaemon macrodactylus were dominant species comprising $84.3\%$ of the total number of individuals. Charybdis japonica, P. gravieri, Oratosquilla oratoria, E. carinicauda, T curvirostris, Metapenaeus joyneri and P. tenella represented $90.6\%$ of the total biomass. While total abundance (number of individuals) was high in spring, total biomass and species richness (number of species) and diversity were high in summer. Cluster analysis, based on monthly abundance data of the 14 most common species, showed that the species were separated into three different groups. Group A composed of Leptochela gracilis, Alpheus japonicus, Crangon uritai, P. macrodactylus, E. carinicauda, P. gravieri, O. oratoria, C. japonica, which were year round residents, group B M. joyneri, T. curvirostris and P. tenella, which were abundant in summer, and group C Crangon hakodatei, Latreutes anoplonyx and L. planirostris, which were abundant in winter. Principal component analysis revealed that seasonal variation in the decapod crustacean assemblage was attributed to the abundance of temporal species such as penaeid shrimps, which were abundant in summer, due to seasonal variation of water temperature and reproductive pattern.

• Ocean and Polar Research
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• v.43 no.1
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• pp.45-51
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• 2021

Studies on marine zooplankton diversity and ecology are important for understanding marine ecosystem, as well as environmental conservation and fisheries management. DNA metabarcoding is known as a useful tool to reveal and understand diversity among animals, but a comparative evaluation with classical microscopy is still required in order to properly use it for marine zooplankton research. This study compared crustacean mesozooplankton taxa revealed by morphological analysis and metabarcoding of the cytochrome oxidase I (COI). A total of 17 crustacean species were identified by morphological analysis, and 18 species by metabarcoding. Copepods made up the highest proportion of taxa, accounting for more than 50% of the total number of species delineated by both methods. Cladocerans were not found by morphological analysis, whereas amphipods and mysids were not detected by metabarcoding. Unlike morphological analysis, metabarcoding was able to identify decapods down to the species level. There were some discrepancies in copepod species, which could be due to a lack of genetic database, or biases during DNA extraction, amplification, pooling and bioinformatics. Morphological analysis will be useful for ecological studies as it can classify and quantify the life history stages of marine zooplankton that metabarcoding cannot detect. Metabarcoding can be a powerful tool for determining marine zooplankton diversity, if its methods or database are further supplemented.

• BMB Reports
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• v.37 no.2
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• pp.177-184
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• 2004

The Crustacean hyperglycemic hormone (CHH) has been shown to exist as multiple molecular forms in several crustacean species. In Penaeus monodon, a gene encoding CHH (so-called Pem-CHH1) was recently described. In this study, the molecular structures of two other CHH genes (Pem-CHH2 and Pem-CHH3) are reported. Both the Pem-CHH2 and Pem-CHH3 genes contain three exons that are separated by two introns that are similar to the structure of other genes in the same family. An analysis of the upstream nucleotide sequences of each Pem-CHH gene has identified the putative promoter element (TATA box) and putative binding sites for several transcription factors. The binding sites for CREB, Pit-1, and AP-1 were found upstream of all three Pem-CHH genes. A Southern blot analysis showed that at least one copy of each Pem-CHH gene was located within the same 10 kb genomic DNA fragment. These results suggest that the CHH genes are arranged in a cluster in the genome of P. monodon, and that their expression may be modulated by similar mechanisms.

• Journal of Aquaculture
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• v.19 no.1
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• pp.1-6
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• 2006

The tryptic enzyme activities from hepatopancreas, foregut, midgut and feces were examined to optimize the feeding method in whiteleg shrimp, Litopenaeus vannamei. The highest tryptic enzyme activity was found in hepatopancreas. The enzyme activities of hepatopancreas were 4 times higher than those of foregut per mg dry weight at 30 minutes feeding. Post feeding period, the activities of hepatopancreas increased continuously up to 30 hours after feeding. Trypsin activities of foregut showed about 3 times higher than did those of midgut. Average activity of foregut reached the pick with $303{\pm}68\;(mean{\pm}SE)$ nmol/mg/min at two hours after feeding and kept the activity up to 4 hours after feeding and thereafter the activity decreased. Average tryptic enzyme activity of midgut increased to $96{\pm}26nmol/mg/min$ up to two hours after feeding and it decreased to $52{\pm}17nmol/mg/min$ at five hours after feeding eventhough the gastric evacuation rate was still 50% by then. Foregut clearance occurred in 30 minutes after feeding and midgut weight increased up to 2 hours after feeding. Also we found that the maximal food ingestion in foregut was equivalent to the average 0.3% of its body weight by 30 minutes after feeding. Up to 5 hours after feeding, the weight ratio of midgut to body weight reduced, but still the weight ratio of foregut to body weight kept the similarity until then. These indicated that the tryptic enzyme activity and the clearance rate are different among the digestive organs and between forgot and midgut during the post feeding period in whiteleg shrimp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.5
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• pp.456-460
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• 2009

Biofilm is a structured community of microorganism encapsulated within a self-developed polymeric matrix and adherent to a living or a solid surface. In this study, we investigated the effects of various substrates on the formation of biofilm in Vibrio parahaemolyticus. We found that biofilm formation profoundly increased in a substrate, that consisted of calcium chloride, calcium nitrate, and calcium sulfate in 1% peptone water. On the other hand, a dramatic reduction in biofilm formation was observed in a substrate, that consisted of glucose and ferric chloride in LB broth. These results suggest that V. parahaemolyticus prefer to form a biofilm on the surface of a crustacean or a clam, where calcium ion is rich, and also where seawater temperature is relatively lower. In contrast, high levels of glucose in a crustacean or a clam body resulting from increased seawater temperature, can make V. parahaemolyticus detach from it and lead to free floating.

• Environmental Engineering Research
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• v.15 no.1
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• pp.23-27
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• 2010

Genotoxic- and ecotoxic assessments of silver nanoparticles (AgNPs) were conducted on the freshwater crustacean Daphnia magna. AgNPs may have genotoxic effects on D. magna, given that the DNA strand breaks increased when exposed to this nanoparticle. Increased mortality was concomitantly observed with DNA damage in the AgNPs-exposed D. magna, which suggests AgNPs-induced DNA damage might provoke higher-level consequences. The results of the comparative toxicities of AgNPs and Ag ions suggest that AgNPs are slightly more toxic than Ag ions. Overall, these results suggest that AgNPs may be genotoxic toward D. magna, which may contribute to the knowledge relating to the aquatic toxicity of AgNPs on aquatic ecosystems, for which little data are available.

• Animal Systematics, Evolution and Diversity
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• v.36 no.4
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• pp.408-415
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• 2020

The suborder Hyperiidea is an abundant crustacean zooplankton in pelagic communities with copepods and euphausiaceans. Hyperiidean amphipods are known to be commensals or parasites of gelatinous organisms such as medusae, siphonophores, ctenophores, and salps. Korean hyperiid amphipods have not received taxonomical attention since the 1970s. During a survey of pelagic crustacean species, two species of hyperiid amphipods, Phronima atlantica Guérin-Méneville, 1836 belonging to the family Phronimidae and Oxycephalus clausi Bovallius, 1887 belonging to the family Oxycephalidae, were found on Dokdo, East Sea, Korea. These two species are new to Korean waters. In the present study, we provide descriptions and illustrations of these two hyperiid species.

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.354-360
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• 1997

This study was intended that the biochemical patterns, bioserological characteristics, resistance of antibiotics, and transferable resistance patterns of 35 Dscherichia coli strains from 79 fish and shellfish samples in marine markets from August to October, 1995. The Standard plate count, coliforms and fecal coliforms were also counted in the 79 cases and analysed the correlationship each other. Geometric means of Standard plate count in seawater fish, shellfish, mollusca and crustacean were 1.4$\times$105 CFU/g, 4.0$\times$105 CFU/g, 2.4$\times$105 CFU/g, 4.7$\times$105 CFU/g, and those of coliforms were 1.3$\times$103 CFU/g, 4.8$\times$103 CFU/g, 8.9$\times$102 CFU/g, 5.8$\times$103 CFU/g. There were no fecal coliforms in the fish and mollusc. However, the geometric means of coliforms in the shellfish and crustacean (1.1$\times$101 CFU/100g, 10 CFU/100 g) were less than those of fish and mollusca. The important biochemical characteristics of E. coli distinguished from the shellfish and crustacean were motility, ornithine decarboxylase, mucate, esculin. The fermentative properties of E. coli were also sucrose, salicin, sorbitol, and raffinose. Of 35 isolates of E. coli, 13 strains (37.1%) showed the pathogenic O antisera, which were O:27 3 strains (23.1%), ):159 2 strains (15.4%) and ):148, O:119, O:142, O:158, O:136, O:18, O:128, and O:168 1 strain (7.7%),respectively.