• Animal cells and systems
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• v.3 no.4
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• pp.375-383
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• 1999

Gonadal development, gametogenesis, reproductive cycle, and first sexual maturity of Reishia clavigera were investigated monthly from July 1998 to June 1999 through cytological and histological observations. R. clavigera had separate sexes, and was an internal fertilizer. The ma1e penis was located near the two tentacles. The ovary and testis were composed of a great number of oogenic lobules and spermatogenic tubules, respectively. The size of ripe oocyte ranged from 130 to 140 ${\mu}$m in diameter. The peripheral cytoplasm of the germinal vesicle of the ripe oocyte in many cases were surrounded by smaller yolk granules, while the eccentric cytoplasm was occupied with larger ones. The reproductive cycle of R. clavigera could be classified into five successive stages: early active, late active, ripe, spawning, and recovery. Spawning of females occurred from early July to August when the seawater reached above 24.8$^{\circ}C$. Spawning of males occurred from early June to August in the water above 22.8$^{\circ}C$. Minimum size for sexual maturity of both sexes was above 10.0 mm in shell height. Each egg capsule was a cylinder or spindle in shape, 4-6 mm in length and 1-2 mm in width. Colors of newly spawned egg capsules showed yellowish white or pale yellow, while those with veliger larvae showed pale black, and released larvae or dead egg capsules showed black violet. The fecundity in an egg capsule ranged from 70 to 91 eggs (mean＝80.28 eggs).

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.172.1-172
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• 1999

No Abstract, See Full Text

• The Korean Journal of Ecology
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• v.23 no.1
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• pp.51-57
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• 2000

Concentrations of cadmium, copper and zinc were determined in three molluscan species including Sacculosiphonaria japonica, Reishia clavigera and Crassostrea gigas to assess heavy metal contamination in the Onsan Bay. The range of cadmium concentrations were 3.83∼39.67 ㎍/g d.w. in S. japonica, 7.47∼103.47 ㎍/g d.w. in R. clavigera, 1.32∼92.17 ㎍/g d.w. in C. gigas. Concentration of cadmium at contaminated site in C. gigas was 70 folds higher than that of reference site. The range of copper concentrations were 22.92∼1287.56 ㎍/g d.w. in S. japonica, 37.53∼656.97 ㎍/g d.w. in R. clavigera, 161.50∼3208.52 ㎍/g d.w. in C. gigas. The concentration of copper at contaminated site in S. japonica was 56 folds higher than that of reference site. The range of zinc concentrations were 93.48∼377.40 ㎍/g d.w. in S. japonica, 423.65∼1075.57 ㎍/g w. in R. clavigera, 2018.13∼22275.00 ㎍/g d.w. in C. gigas. The difference of zinc concentrations between reference site and contaminated site was relatively small than those of cadmium and copper in all the species tested. The largest difference was 11 folds in C. gigas. In the present work, we confirmed that all of these species, S. japonica, R. clavigera and C. gigas, could be used as biological indicators to monitor heavy metal contamination.

• 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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.843-852
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• 2022

To determine the composition of benthic species on the southwest coast, a macrobenthos study was conducted at 18 sites on the islands of Wando and Jodo for seven summers (2014-2021) from June to September. Two hundred and twenty species(645 ind./m²) were collected on the rocky shores of Wando and Jodo. A similar number of species was observed in Wando (165 species) and Jodo (167 species). The mean density was higher in Wando (726 ind./m²) than in Jodo (564 ind./m²). The number of species was the highest at Site 15 (116 species), and the density was highest at Site 7 (1,664 ind/m²). The dominant species were Nodilittorina radiata with 175 ind./m² (27.1%), Littorina brevicula with 97 ind./m² (15.1%), and Heminerita japonica with 41 ind./m² (6.3%). The climate change indicator species, Tetraclita japonca, appeared in 15 sites, and the endemic species, Ptilohyale bisaeta, appeared in some sites. Fusinus spectrum, which appears on the Red List as a Near Threatened (NT) species, the lowest level of extinction risk, appeared in Jodo. The macrobenthos of Wando and Jodo demonstrated the general characteristics of rocky shores in Korea. Based on the tides and substrate, the rocky shores revealed a vertical distribution trend where Nodilittorina radiata, Littorina brevicula, Chthamalus challengeri, and Reishia clavigera were dominant. Wando and Jodo exhibited similar habitat distribution patterns.

• KOMUNHWA
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• no.70
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• pp.63-88
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• 2007

The purpose of this writing is to examine the places and instruments of the dissection for deformed animal carcasses excavated in shellfish stacks of the period of the Proto-Three Kingdoms(삼한) and the Three Kingdoms(삼국). The remains were chosen, which had been excavated and finished in the analysis of the animal carcasses, and the main objects are all shells and deer, especially among Mammalia. As the result, the dissection of shells was not taken place in the habitats of the animals, but inside or around of the residence of the people. For deer, too, it was done in the public place or specific area around and inside the residence. As concerns the method of dissection for shells, for Pelecypoda(부족류), represented by Meretrix lusoria(백합), the inner meat was taken out by wrenching the shell with a kind of small knives, or by boiling, and sometimes by cracking the middle of the shell in the case of big Meretrix lusoria and Dosinorbis japonicus(떡조개). For Rapana venosa(피뿔고둥), representative of Gastropoad(배발류), the people broke the top or some parts of the body to get the inner meat or used some kind of needles and stylus to pick the inner meat out after boiling. Abalones‘ meat was attached firmly to the shell, so very sharp and proper metal instruments were used to take the meat out Relatively small-sized Reishia clavigera(대수리),Top shell(밤고둥) meats were taken out by breaking the top parts after boiling, then sucking the meats, or by picking them out by using needles and stylus in the original shape. In the case of large Mammalia like deer, in the full consideration of the point that deer itself are used in various ways, they were dissected in the order of skinning, taking out the internal organs, cutting front and rear legs, separating joint parts and meats, extracting bone-marrow by 철정, 철부, ironed hand knife in very delicate ways. It seems that skinning, and front and rear legs' cutting were taken place in the place around the residence, on the other hand joint parts' separating and bone-marrow extracting in the residence. The tools for the dissection were confirmed to be hand-knife, honed ax, hammer stone, bondstone, needles and stylus, and some other sharp instrument. They were used properly according to objects.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.6
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• pp.853-865
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• 2022

In this study, from August to October 2019, we conducted a survey of the spatial distribution and dominant species of macrobenthos on the rocky intertidal zones of 38 specified islands distributed along the southern coast of Korea. On the basis of observation made using 50 × 50 cm quadrats, we identified a total of 80 species, among which, Mollusca were the most abundant fauna, with 54 species that accounted for 67.4% of the total, followed by Crustacea with 15 species (18.7%). The recorded numbers of Cnidaria, Porifera, and Echinodermata species ranged from 1 to 6. In terms of the regional patterns of species richness, specified islands in Yeosu were found to be the most species rich, supporting 61 species, whereas islands in Hadong, Namhae, and Chujado were found to have a similar level of species richness, ranging from 42 to 46 species. Islands in Boseong and Goheung were home to the fewest species, with only 29 species being recorded. At the sampling station scale, we noted a considerable difference in faunal richness, ranging from 6 (St. 6) to 33 (St. 20) species. Among the recorded species, Echinolittorina radiata was identified as the dominant species on 15 specified islands, with the next most abundant species being Tetraclita japonica, considered an indicator species of climate change, which was recorded on 11 islands. In terms of frequency, E. radiata, found on 36 islands, was identified as the most frequently occurring species, followed by Reishia clavigera (30 islands), Mytilisepta virgata (29), Nerita japonica (28), Ligia. exotica (27), and Littorina brevicula (26). Of the 80 species identified, 9, 4, and 2 species of Mollusca, Crustacea, and Cnidaria, respectively, are classified as Marine fauna of accepted foreign export, whereas 50 are Red List species, 44 are species of Least Concern, 3 are Data Deficient species, and 1 species was not evaluated. However, during the survey, we found no Near Threatened or Not Applicable species. On the basis of the findings of this survey, it would appear that the abundance and richness of macrobenthic fauna inhabiting the rocky intertidal zones of specified islands along the southern coast of Korea differ according to different habitat conditions, particularly with respect to the duration of exposure and the extent and properties of the substrata. The findings of this study will provide baseline data for future monitoring and management of specified islands in Korea.