• Development and Reproduction
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• v.2 no.1
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• pp.81-87
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• 1998

A scanning electron microscopic study on the glochidial encystment and excystment during the development of Anodonta arcaeformis flavotincta on Carassius auratus, a common natural host fish, was carried out. The glochidia were attached to the fins, buccal cavity and gills of the host fish within 30 minutes. In this study, the fins of host fish infected with the glochidia were examined in a time series. The attachment rates of the glochidia on the pectoral fins, caudal fin and pelvic fins of the host fish were 30%, 22%, and 17%, respectively. The glochidia which attached to the fish became encysted within 27 hrs. The process of encystment progressed slowly. Ti took 24 to 27 hours in the formation of the primary cyst, and after 5 to 6 days, the larvae was covered completely with the epithelial cels of the host tissues. The process of detachment of juvenile clam was observed on the 8th day after host infection. Most of the juvenile clams have sloughed from the cyst of the host within 15 days. No significant size difference was observed in the glochidia and the juvenile which were found before attachment and after detachment from the cyst of the host fish.

• The Korean Journal of Malacology
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• v.5 no.1
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• pp.29-34
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• 1989

의암호에서 채집된 작은애칭이(Anodonta aracaeformis)와 펄조개(Anodonta woodiana despecta)의 유생을 줄납자루(Acheilognathus yamatautae), 돌고기(Pungtungia heizi), 붕어(Carassius auratus)를 숙주로 하여 인위 감염 시킨 결과는 다음과 같다. 1. 펄조개 glochidium 의 부착기간은 줄납자루, 돌고기에 각각 10일과 9일이었고 작은대칭이glochidium은 붕어에 21일간 부착하였다.2. 펄조개, 작은 대칭이 glochidium은 숙주의 가슴지느러미와 아가미에 높은 부착률을 나타내었다.3. 펄조개glochidium의 부착전과 후의 크기 변화는 없었으나 작은 대칭이 glochidium의 경우는 각고, 각장, 인대길이의 부착전 평균 크기가 0.345mm, 10365mm, 0.271mm에서 21일 이후 이탈 직전의 평균 크기는 0.373mm, 0,386mm, 0.290mm로 외형적인 크기 증가를 나타내었다.4. 펄조개 glochidium감염에 대한 숙주의 민감성은 줄납자루가 돌고기보다 높게 나타났다.5. 펄조개 glochidium은 부착후 2일, 작은대칭이는 8일째부터 기관 형성을 관찰할 수 있었다.

• The Korean Journal of Malacology
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• v.23 no.2
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• pp.181-187
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• 2007

A scanning electron microscopic study on the glochidium and glochidial encystment of Anodonta arcaeformis on the host fish Carassius auratus was conducted. The shape of the glochidium was apparently subtriangular and its average size was $270\;{\mu}m\;\times\;260\;{\mu}m\;\times\;145\;{\mu}m$. The glochidial shell valves were of the same size, kept together by a ligament that is 50.4 ${\mu}m$ in length and 5.5 ${\mu}m$ in width. Each of the glochidial shell valve had a long hook studded with many spines on the superior face. A large area of at the apex of the valve surrounding the base of the hook was provided with numerous small spines which became progressively smaller toward the periphery of the area. The glochidial shell valve consisted of two layers. The mantle cells line the glochidial shell valves and some of hair cells were observed. A larval thread was 2.3 ${\mu}m$ in diameter. In the artificial infection of the glochidia to one of the natural hosts, Carassius auratus, it took about three to four hours to encyst the glochidia with epithelial cells of the fish fins. The encystment method was the cell migration from the neighboring epithelial cells.

• The Korean Journal of Malacology
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• v.9 no.1
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• pp.46-62
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• 1993

Six species of freshx\water Unionidae mussels in Korea, Anodonta arcaeformis flavotincta, A. woodiana, Unio douglasiae, U. douglasiae sinuloatus, Lamprotula gottschei, Lanceolaria acorohyncha were compared in regard to the various taxonomical characteristics of ultra structures of shells and glochidia. The results obtained in this study are summarized as follows;the orter demibranchs of all the females of six species have served as marsupial(gravid)pouch. However, all the foru demibranchs were used as the marsupium in some female individuals of L. gottschei. The glochidia of A. arcaeformis flavotincta, A. woodiana and L. gottschei were separated one by one with the mucous strings and U. douglasiae sinuolatus were round-subtriangular in shape, and those of L. gottschei were subelliptical in shape. Each of the glochidial shell valves of six species had a hook studded with many spines on the superior face on valve. The glochidial shell valve had two or three rows of large spines; A. arcaeformis flavotincta, A. woodiana, and L. gottschei had two rows and three rows in U. douglasiae, U. douglasiae sinuolatus, and L. acrorhyncha. The numbers of sensory hairs of A. arcaeformis flavotincta and A. woodiana were all eight, those of U. douglasiae, U. douglasiae sinuolatus and L. acrorhyncha were six. and that of L. gottschei was four. The external and internal surfaces of the glochidial shell valves of A. A. arcadformis flavotincta, A. woodiana, and L. gottschei had foveolate and psilate in U. douglaseae, U. douglasiae sinuolatus and L. acrorhyncha.

• The Korean Journal of Malacology
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• v.11 no.2
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• pp.147-163
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• 1995

The unionid family Unionidae contains several genera in Korea, among which occru considerable variations in life histories and sexual conditions. Seven species from the Korea(Anodonta arcaeformis flavotincta, A. woodiana, Unio douglaseae, U. douglasiae sinuolatus, Lamprotula gottschei, Lanceolaria acrorhyncha, Solenaia triangularis)were stueide in order to identify and describe the seasonal gonadal activity and the visceral sex. The gonads of seven species were histologically examined by using the paraffin block technique for sectioning. All seven species were uniformly dioecious and testicular activity in six species except one species, S. triangularis, generated sperm-morulae(multinucleated cell). The annual reproductive cycle of the seven species could be classified into five successive stages; multicative, growing, mature, spent, deginerative and resting stages. The breeding season of six species was the summer and that of A. a. flavotincta was the winter.

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.53-70
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• 2003

In order to understand freshwater molluscan fauna in Asan area, a survey was conducted on the watersheds of this area during the period of October 1999 to August 2000. For the purpose of easy overlook of the molluscan fauna in Asan area, present survey was undertaken on a total of 101 sampling sites of 4 major watersheds connected along Onyang River, Gokgyo River, Sapgyo Lake, and Asan Lake. The collected freshwater mollusks were analysed based on the environment of their habitats. The freshwater mollusks collected through out the present survey were 27 species, 12 families, 5 orders, and 2 classes. Of these, gastropods were 18 species, 10 families, 3 orders; and bivalves were 9 species, 2 families, and 2 orders. The dominant gastropods in this area were Radix auricularia coreana, Cipangopaludina chinensis malleata, Hippeutis cantori, Physa acuta, Gyraulus convexiusculus and Austropeplea ollula and the dominant bivalves were Anodonta arcaeformis, Anodonta arcaeformis flavotincta, and Anodonta woodiana. Dominant species in rice fields were Fossaria truncatula, Segmentina hemisphaerula and Physa acuta, dominant species in rivers were Radix auricularia coreana, Physa acuta, and Hippeutis cantori. Dominant species in reservoirs were Cipangopaludina chinensis malleata, Radix auricularia coreana, Austropeplea ollula, and Fossaria truncatula. Dominant species collected in lakes were Cipangopaludina chinensis malleata, Hippeutis cantori, Cipangopaludina japonica, and Radix auricularia coreana. Radix auricularia coreana, Cipangopaludina chinensis malleata, and Austropeplea ollula were dominantly inhabiting on the muddy bottoms. Anodonta woodiana, Cipangopaludina japonica, and Corbicula fluminea occurred mainly in the gravel areas. Radix auricularia coreana, Cipangopaludina chinensis malleata, and Hippeutis cantori were dominant in the muddy rock areas. Rock-dominant species were Radix auricularia coreana, Semisulcospira forticosta and Koreanomelania paucicincta. Sand-dominant species were Physa acuta, Radix auricularia coreana, and Hippeutis cantori. Sand gravel-dominant species were Physa acuta, Radix auricularia coreana, and oreanomelania paucicincta. Hippeutis cantori, Cipangopaludina chinensis malleata, and Gyraulus convexiusculus occurred in the sand-muddy areas. Cristaria plicata, appointed as an endangered species from the "Natural Environmental Conservation Law", was collected from 5 sampling sites (site Nos. 45, 47, 48, and 52). For the endangered species found in this survey should be make appropriate protection.

• Korean Journal of Ichthyology
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• v.6 no.1
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• pp.39-50
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• 1994

Spawning of the bitterling, Acheilognathus yamatsutae into the mussel was studied from 1990 to 1992 in Lake Uiam, Korea. This fish preferred to spawn in certain mussel species such as Unio douglasiae, U. douglasiae sinuolatus, Lamprotula gottsehei and Anodonta arcaeformis flavotincta in order of preference. Within the same species of mussel, they preferred the larger size. Eggs and larvae were commonly located in the inner demibranch of mussels. Average number of eggs or larvae per mussel was 3.6(ranged from 1 to 35). The eggs of the bitterling were hatched out within 41 hours when water temperature remained over $20^{\circ}C$ and the larvae already possessed minute tubercles on the skin and yolk projections to prevent themselves being washed out from mussels.

• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.39-48
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• 2021

In order to control algal bloom, which causes environmental problems such as eutrophication in freshwater ecological environments, many attempts have recently been made using biological approaches. Among them is filtration using bivalve. Algae control with filter-feeding bivalves is emerging as an eco-friendly method. In this study, bivalves collected at Baekje weir in Geum River in Korea from Jun to Sep 2020 were tested to find out the possibility of algae control using filter-feeding bivalves through laboratory experiments. The Unio douglasiae, Anodonta woodiana, and Anodonta arcaeformis collected from Baekje weir were put into a water tank (2 L) containing Clorella vulgaris, and as a result, the average filtration rate was 95.9% per animal after 24 hrs. Calculating this with the Chl-a concentration converted to a calibration curve, it was found that the average of 154.84 ㎍ L^-1 of Chl-a was reduced. Based on this calculation, the possibility that one bivalve can eliminate Chl-a in one month is 0.0005%. It is expected that the effect is 20.14% when there are 40,000 animals. These results indirectly showed how effective bivalve's ability to control Chl-a in their habitat is. Although this study was limited to calculating the algae control ability of aquatic ecosystem based on the filtration rate of bivalve and the corresponding Chl-a reduction rate, it is thought that it will be used as basic data for integrated research from various factors and viewpoints (phytoplankton, aquatic plants, benthic organisms, and sediments) through additional research.

• Korean Journal of Environmental Biology
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• v.41 no.3
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• pp.229-246
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• 2023

The bitterling (Cyprinidae, Acheilongnathinae) is a temperate freshwater fish with a unique spawning symbiosis with host mussels. Female bitterlings use their extended ovipositors to lay eggs on the gills of mussels through the mussel's exhalant siphon. In the present study, in April of 2020, we investigated spawning frequencies and patterns of three bitterling fish species in host mussel species in the Nakdong River basin (Hoecheon). During field surveys, a total of four bitterling and three mussel species were found. We observed bitterling's spawning eggs/larvae in the three mussel species: Anodonta arcaeformis(proportion spawned: 45.5%), Corbicula fluminea(12.1%), and Nodularia douglasiae (45.2%). The number of bitterlings' eggs/larvae per mussel ranged from 1 to 58. Using our developed genetic markers, we identified the eggs/larvae of each bitterling species in each mussel species (except for A. macropterus): A. arcaeformis (spawned by Acheilognathus yamatsutae), C. fluminea (A. yamatsutae and Tanakia latimarginata), and N. douglasiae (A. yamatsutae, Rhodeus uyekii, and T. latimarginata). Approximately 57.6% of N. douglasiae mussel individuals had eggs/larvae of more than one bitterling species, suggesting that interspecific competition for occupying spawning grounds is intense. This is the first report on bitterling's spawning events in the Asian clam C. fluminea from Korea; however, it should be ascertained whether bitterling's embryo undergoes successful development inside the small mussel and leaves as a free-swimming juvenile. In addition, the importance of its conservation as a new host mussel species for bitterling fishes needs to be studied further.