• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.138-143
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• 2011

The efficiency of mtCOI amplication after DNA extraction of benthic harpacticoid Tigriopus japonicus s.l. was tested under different conditions depending on fixative (99% Ethanol, or 4% Formalin) and additional chemicals (Ludox or Rose Bengal). Each experimental group by the fixative was subdivided into four groups, respectively: 1) Control (fixative only), 2) processed with Ludox HS40, 3) processed with Rose Bengal, and 4) processed with both Ludox HS40 and Rose Bengal. For the 99% ethanol-fixed sample, overall success rate of amplification by PCR was 96% or above, while for the 4% formalin-fixed one, success rate was much lower than those of ethanol-fixed: 1) Control: 27%, 2) Ludox HS40: 3%, 3) Rose Bengal: 7%, and 4) Ludox HS40 and Rose Bengal: 3%. As a result present study verify that 99% ethanol is a proper fixative for DNA extraction in meiofauna organisms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.4
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• pp.358-364
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• 2003

Gross energy intake fecal, nitrogen excretory and metabolized energy of snotted halibut juvenile, Eopsetta grigorjewi, fed on Tigriopus iaponicus (Group A) and the enriched Artemia nauplii (Group B), were quantitatively investigated and represented as balance equations of energy and material. Absorption efficiency (AE), gross conversion efficiency $(K_1)$ and net conversion efnciency $(K_2)$ were also estimated to understand the changes in efficiency by the prey Gross energy intake, fecal, nitrogen excretory, metabolized and growth energy of Group A were $2.790\pm0.247,\;0.495\pm0.046,\;0.018\pm0.003,\;0.214\pm0.047\;cal\;mg^{-1}\;day^{-1}$ and $2.063\;cal\;mg^{-1}\;day^{-1},$ respectively. The same parameters of Group B were $4.801\pm0.165,\;0.579\pm0.031,\;0.055\pm0.010,\;0.306\pm0.048\;cal\;mg^{-1}\;day^{-1}$ and $3.861\;cal\;mg^{-1}\;day^{-1},$ respectively. Energy budget of Group A and B were represented as 100 C= 7.67 M+17.7 F+0.65 U+73.94 G and 100C=6.37 M+ 12.1 F+1.15 U+80.42 G, respectively, where C, M, F, U, and G represent gross energy intake, metabolized energy, fecal energy, nitrogen excretory (non-fecal) energy and growth energy, respectively. AEs of Croup A and B were $81.52\pm1.89,\;86.79\pm0.70\%,$ respectively, with significant difference at p=0.01 level. However, $K_1\;and K_2$ of Group A and B showed no significant difference at p=0.01 level, with $74.21\pm6.57,\;80.48\pm2.76\%\;and\;91.17\pm7.26,\;92.74\pm2.69\%$ respectively. These results suggest that T. japonicus is a possible substitute for Artemia nauplii for the snotted halibut juvenile.

• Journal of the Korean Society for Marine Environment & Energy
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• v.15 no.4
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• pp.281-291
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• 2012

In this study, WET (whole effluent toxicity) test with Skeletonema costatum, Tigriopus japonicus and Paralichthys olivaceus and ERA (environmental risk assessment) were conducted to assess the unacceptable effect on marine ecosystem by emitting the treated discharge water from 'ARA Plasma BWTS' BWMS (ballast water management system) using filtration, Plasma and MPUV module. 34 psu treated discharge water from ARA Plasma BWTS shown slight chronic toxicity effect on the P. olivaceus ($7d-LC_{50}{\Rightarrow}100.00%$ treated discharge water, $7d-LC_{25}{\Rightarrow}85.15%$ treated discharge water). Bromobenzene, chlorobenzene and 4-chlorotoluene in 34 psu treated discharge water from ARA Plasma BWTS were higher than in the background original content of seawater. The PECs (predictive environmental concentrations) of bromobenzene, chlorobenzene and 4-chlorotoluene calculated by MAMPEC (marine antifoulant model to predict environmental concentrations) program (ver. 3.0) were 3.34E-03, 2.10E-03 and 1.73E-03 ${\mu}g\;L^{-1}$, respectively and PNECs (predicted no effect concentrations) of them were 1.6, 0.5 and 1.9 ${\mu}g\;L^{-1}$. The PEC/PNEC ratio of bromobenzene, chlorobenzene and 4-chlorotoluene did not exceed one and 3 substances did not consider as persistence, bioaccumulative and toxic. Therefore, it was suggested that treated discharge water from ARA Plasma BWTS did not pose unacceptable effect on marine ecosystem.

• Ocean and Polar Research
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• v.36 no.2
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• pp.199-208
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• 2014

Copepods are a major food source for marine fish larvae in nature. Many studies on copepods culture have been conducted to develop a new live food for the seedling production of marine fish larvae. But fish farmers still depend on rotifer and Artemia nauplii. This study was carried out to find suitable copepods as live food for the larvae in hatchery. Eight species of copepods (1 calanoid, 2 cyclpoid, 5 harpacticoid) that were fed Isochrysis galbana were examined in terms of the size of nauplii, fecundity, amino acids, and fatty acids contents. These species were divided into small (nauplii length 46-86 ${\mu}m$) and large (nauplii length 120-188 ${\mu}m$) size group. Nitokra spinipes in the small group and Tigriopus japonicus in the large group showed the highest fecundity with 151.1 and 139.6 nauplii production per gravid female, respectively. With regard to nutrients, essential amino acids were the highest with 21.2% in cyclopoid Paracyclopina nana in the small group and n-3 HUFA were the highest in calanoid Pseudodiaptomus inopinus (8.5 ${\mu}g/mg$) in the large group and P. nana (8.8 ${\mu}g/mg$). In terms of the size, fecundity, and nutritional value of copepods examined in this study, N. spinipes and P. nana seem to be suitable copepod species to develop as a new live food for small mouth fish larvae.

• Journal of Environmental Science International
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• v.20 no.11
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• pp.1383-1394
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• 2011

Environmental impacts of suspended solids (SS) released in coastal area by dredging, reclamation and construction can cause serious damages to coastal habitats and benthic organisms. Acute toxicity tests (4-7 days) were conducted to identify the relationship between SS concentration and mortality of three marine benthic species; benthic copepod (Tigriopus japonicus) adult, Pacific abalone (Haliotis discus hannai) spat, and olive flounder (Paralichthys olivaceus) fry. Benthic copepod was the most sensitive to SS followed by olive flounder fry and Pacific abalone spat, with an $LC_{50}$ (lethal concentration of 50% mortality) value of 61.0 mg/L and LOEC (lowest observed effective concentration) value of 31.3 mg/L for benthic copepod. LOEC and 7 day-$LC_{50}$ for Pacific abalone spat were 500.0 mg/L and 1887.7 mg/L, and those for olive flounder fry were 125.0 mg/L and 156.9 mg/L, respectively. The tolerance limits of the test species to SS revealed the various concentration ranges of SS, which reflects the physiology and ecology of the test species. These results are very valuable for the determination of SS concentration of effluents released into the coastal area by dredging, reclamation and construction etc. Also, sharp increase of SS can cause long-term damages to the benthic and sessile fauna by blanketing of benthic substratum. These experimental procedures for marine bioassay and acute toxicity results can be a useful guideline for practical management planning of SS discharge into coastal area.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.267-272
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• 2016

The feeding habits of Chaenogobius annularis were studied based on gut contents analysis of 315 individuals, collected from September 2014 to August 2015 in the tidepools at the intertidal zone of Tongyeong, Korea. The size of C. annularis ranged from 17.0 to 54.0 mm in standard length (SL). C. annularis mainly consumed copepods (especially Tigriopus japonicus). Its diets included seaweeds, cirripeds, mysids and amphipods. C. annularis showed ontogenetic changes in feeding habits. Small individuals fed mainly on copepods. As body size increased, the portion of seaweed increased, whereas the consumption of copepods decreased.

• Molecules and Cells
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• v.22 no.3
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• pp.314-322
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• 2006

The whole mitochondrial genome (14,915 nt) of Pollicipes mitella (Crustacea, Maxillopoda, Cirripedia, Thoracica) was sequenced and characterized. It is the shortest of the 31 completely sequenced crustacean mitochondrial genomes, with the exception of a copepod Tigriopus japonicus (14,628 nt). It consists of the usual 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 relatively short non-coding region (294 nt). The thoracican cirripeds apart from Megabalanus volcano have the same arrangement of protein-coding genes as Limulus polypemus, but there are frequent tRNA gene translocations (at least 8). Some interesting translocation features that may be specific to the thoracican cirriped lineage are as follows: 1) trnK-trnQ lies between the control region and trnI, 2) trnA-trnE lies between trnN and trnS1, 3) trnP lies between ND4L and trnT, and 4) trnY-trnC lies between trnS2 and ND1. In P. mitella there are two trnL genes (L1 and L2) in the typical crustacean positions (ND1-L1-LrRNA and CO1-L2-CO2). The present result is compared and discussed with the other three cirriped mitochondrial genomes from one pedunculate (Pollicipes polymerus) and two sessiles (Tetraclita japonica and M. volcano) published so far. Mitochondrial protein phylogenies reconstructed by the BI and ML algorithms show that the thoracican Cirripedia is monophyletic (BPP 100/BP 100) and associated with Remipedia (BPP 98/BP 35). In addition, Oligostraca, including Ostracoda, Branchiura, and Pentastomida, is a monophyletic group (BPP 99/BP 68), and is basal to all the other examined arthropods. Remipedia + Cirripedia appears as an independent lineage within Arthropoda, apart from Thoracopoda (Malacostraca, Branchiopda, and Cephalocarida). The Thoracopoda is paraphyletic to Hexapoda. The present result suggests that the monophylies of Crustacea and Maxillopoda should be reconsidered.

• Journal of Aquaculture
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• v.18 no.1
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• pp.13-18
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• 2005

This study was to investigate the effects of water temperature and food on the mass seed production of larval parrot fish, Oplegnathus fasciatus. Growth of the larvae reared at heated water temperature ($25.3^{\circ}C$) was significantly higher than that of the larvae reared at natural water temperature ($20.5^{\circ}C$). In addition, survival rate of the larvae at heated and natural sea water temperature were $24.0\%$ and $12.3\%$, respectively (P<0.05). Growth and survival rate of the larvae fed mixed diets of Nannochloropsis oculata, rotifer (Brachionus rotundiformis). Artemia nauplii, Tigriopus japonicus and artificial diets were significantly higher than that of the larvae fed only either rotifer or artificial diets (P<0.05). The average survival rate and total length of the larvae reared for 50 days after hatching were $22.5\%$ and 62.0$\pm$4.0 mm, respectively. Amount of consumed rotifers at one time feeding by a larva was rapidly increased with growth from 10.3 individuals per larva 5 day old to 65.5 individuals per larva 20 day old.