The reproductive ecology of the purple shell, Rapana venosa was investigated by the histological observations on depositions of the egg capsules, and hatching of larvae in the laboratory and the subtidal zone of the vicinity of piung-do, Chollabud-do, west coast of korea, for one year from June 1992 to May 1993. The results are summarized as follows:1. Rapana venosa is dioecious in sex. The ovary is composed of a number of ovarian lobules, and the testis comprises a number of ovarian lobules, and the testis comprises of gonads could be classified into 4 stages in males and 5 stages in females: 1) growing stage(in female subdivided into 2 stages of early and late growing stage). 2)mature stage. 3)spent stage or copulationstage. 4)rdcovering stage. The early growing stage in females of the purple shell was in September through February, late gorwing stage was in October to March, mature stage was in September to January, mature stage was in September to July, copulation stage was in Februaty to June and recovering stage in April to October.3. Spawning occurred 3-4 times at intervals of 1-3 days, and completed within 10 days from the beginning of spawning during the spawning season of the year.4. From the results of laboratory and field observations, egg masses are composed of a number of egg capsules, egg masses are occurred from May to late August, and in mid August depositions of egg mass in composed of 90-113 egg capsules, fecundity in an egg capsule was ranged 984 to 1,241 eggs(average 1,096 egg). Therefore, fecundity in total egg capsules spawned per individual during the spawning season is estimated as approximately 320,000 to 450,000 egges.5. The incubation period during deposition of an egg capsule to hatching larvad tood 17 days at 18.3-20.4%C(water temperature)and 1.021 (specific gravity fo sea water).
Contamination of heavy metals in water and sediments along Mangyeong Gang(river) has reached up to critical level The object of the study is to elucidate somed molluscs which inhabit along the river on respect to the modulatory role in reducing the pollution. For the purpose, molluscs which are common in numbers and biomass in the area were collected, and Cadmim(Cd) was subjected as a reference metal in the experiment. The corresponding species were; Cipango;aludina chinensis (muddy snail) and Scapharca subcrenata (seashell). As methods, sample species were kept in laboratory under the natural condition as possible. Soil were brought from the site of the collection, dried autoclaved and wetted with ordinary water. It wad utilized as media to maintain the collected species in vitro all the way of the experiment. CdCI<TEX>$^{2}$</TEX> was mixe in the medium according to experimental design. On the result obtained in the study, it is summarized that molluscs which inhabit along Mangyeong Gang(river)consume heavy mital-containing matters, so far Cd is concerned in the study. The amout of Cd concentration in tissues of the benthic natured invertebrates were dose and time related, and MT-Cd was also similar trend. Thus, Cd may eventually combine with low molecular protein forming metalloprotein, then reduce the toxicity of the heavy metal.
전복, Nordotis discus의 1<TEX>$0^{\circ}C$</TEX>와 2<TEX>$0^{\circ}C$</TEX>의 수온구에서 개체크기별 대사와 폐사에 미치는 부니의 영향에 대한 결과는 다음과 같다.1. 수온 -염분별 산소소비율의 일반적 경향은 고온-고염분에서 큰개체보다는 작은개체에서 그 비율리 높게 나타났다.2. 염분별 두 수온간의 온도계수 (Q <TEX>$_{10)}$</TEX> 는 작은 개체에서 1.2-2.9의 병위를 큰개체의 경우 1.5-3.4의 범위를 나타내었으나 개체크기에 관계없이 유사한 양상을 보였다.3. 부니의 농도별 사망율은 작은 개체의 경우 처리 96시간후 2<TEX>$0^{\circ}C$</TEX>수온에서 부니 농도1000ppm에서 가장 높았고. 큰 개체의 경우 50ppm에서 가장 낮았다.4. 96시간-반치사농도(LC<TEX>$_{50}$</TEX>)는 1<TEX>$0^{\circ}C$</TEX>의 경우, 큰개체에서 1076.58 ppm, 작은 개체에서 812.55 ppm이었으며, 2<TEX>$0^{\circ}C$</TEX>의 경우는 큰개체에서 698.28 ppm, 작은 개체에서 546.74ppm으로 나타났다.5. 부니의 영향으로 인한 호흡산소소비량은 개체크기에 관계없이 1<TEX>$0^{\circ}C$</TEX>에서 보다 2<TEX>$0^{\circ}C$</TEX>에서 더욱 높았으며, 1000ppm에서 70% 이상의 감소율을 나타내었다.
The number of chronosomes and karyotypes in eight species of the family Bradybaenidae were analyzed by air-drying method using gonad. The mitotic haploid chromosome numbers of Acusta despecta sieboldiana were 29 and conisisted of 12 pairs metacentric, 17 pairs submetacentric chromosomes. The mitotic haploid chromosomes were 29 and 11 pairs metacentric and 17 pairs submetacentric and 1 pair telocentric chromosomes in Koreanohadra kurodana; 29 and 10 pairs metacentric chromosomes in K. koreana' 29 and 10 pairs metacentric and 18 pairs submetacentric, and 1 pair acrocentric chromosomes in Karaftohelix adamsi; 28and 10 pairs metacentric, and 18 pairs submetacintric chromosomes in Aegista chosenica; 28 and 14 pairs metacentric and 14 pairs submetacentric chromosomes in A.(Plectotropis) diversa; 28 and 15 pairs metacentric, 10 pairs submetacentric and 3 pairs acrocentric chromosomes in A. (p.)quelpartinsis; 29 and 12 pairs metacentric and 9 pairs submetacentric and 2 pairs telocentric chromosomes in Nesiohelix samarangae.
These studies were conducted to compare the external morphologies of 15 species of land snails in 8 genera of family Bradybaenidae in Korea. Principal component analyses of 15 species can be divided into five groups based on the morphological characters and the result of cluster analyses were in accord with the principal component analyses. The morphological intraspecific similarity of Nesiohelix samarangae of Mitan and Cheju population(S=0.999) proved to be highest. The degree of interspecific similarity between Aegista(Plectotropis)divesa and Aegista(plectotropis)quelpartensis(S=0.970)were more similar than the other interspecies.
A cladistic analysis for phylogenetic relationship among 3 freshwater planorbid snail species was carried out on the basis of their conchological and anatomical characteristics.The intestinal loop in the digestive systims was mainly distinguishable among 3 species of the planorbid snails. The loops in Hippeutis cantori and Segmentina hemisphaerula coiled around stomach, extended down to the distal part of the liver and finally connected with the anus, while the loop in Gyraulus convexiusculus was short and small, and connected directly to the anus after coiling around the stomach. However, the intestinal loop of Hippeutis cantori was the largest among those of 3 target snail species. In the main morpholohical differences of the riproductive systems, Gyraulus convexiusculus uniquely had a calcareous stylet in the penis sheath. Although there was no stylet in the penis sheath in the other snail species, the penis shesths connected with 1 and 2 flagella in Segmentina hemisphaerula and in Hippeutis cantori, respectively were different from each other. Two planorbid species, Hippeutis cantori and Segmintina hemisphaerula have a more recent phylogenetic ancestor out three species employed including Gyraulus convexiusculus.
A study on the distribution and seasonal changes of the benthic macroinvertebrate community was performed on the 4 intertidal rocky shores of Biyang-do in Chehu Island throughout four seasons from January 1992 to january 1993. The macroinvertebrates composed of 8 phyla, 15 classes, 31 orders, 71 families, 168 species. The seasonal appearing species were 135 species in summer, 127 species in spring, 124 species in winter and 121 species in autumn, respectively. The dominant species of the upper zones were Nodilittorina exigua, Nerita japonica, Pollicipes mitella, the middle zones were Turbo coronata coreensis, Monodonta neritoides, petrolisthes japonicus and the lower zones were Pagurus samuelis, Chthamalus pilsbryi, Chlorostoma argyrostoma lischkei. The community dominance indices of the upper zones were much higher than the middle and lower zones. The seasonal appearnace in species in the lower zones were remarkable, but individual numbes were not. Species diversity and evenness in all investigated zones were highest in spring and lowest in winter. But species richness was highest in summer, lowest in autumm.
Contamination of heavy metals in water and sediments along Mantyeong (river) has reached up to critical level, The object of the study is to dlucidate some macroinvertebrates which inhabit along the river in respect to the modulatory role in reducing the pollution. For the purpose, Scapharca subcrenata(sea shell) which is common in numbers and biomass in the area was collected, and cadmium (Cd) was subjected as a reference metal in the experiment. The seashell was dried and autoclaved, followed by pellet preparation under various concentration of Cd: 50,100,250,500 and 1,500 ug /pellet. Mice were fed for 3 months, althrough last group(5 mice), 1,500 ug/pellet, died within 4 weeksof the administration.MT-Cd in liver and kidney increased in correlation with the amont of Cd concentration in pellet, especially in kidney than in liver. Liver and kidney of the mice showed pathological changes such as cellular infiltration and focal necrosis in liver, and peri-tubular cell infiltration or tubular necrosis etc. The changes were more intensive by amount of the Cd. Overall results in the present study suggest that Cd may eventually combine with soluble-protein forming metalloprotein, then reduce the toxicity of heavy metal, How the formed Mt-Cd is discharged from the kidney and the mechanism shall be the further subject to be clarified.
동양달팽이(Nesiohelix samarangae)의 자성생식기 중 정자낭(spermatheca)의 미세구조를 투과전자현미경을 이용하여 관찰하였다. 성체의 정자낭의 내강에서는 정자와 이와 관련된 물질들 또는 상피로부터의 분비물질들이 관찰되었다. 정자낭의 내강을 둘러싸고 있는 벽의 상피는 단층원주상피로서 내강과 연한 세포의 원형질막은 미세융모를 가지고 있었으며 섬모는 가지고 있지 않았다. 이 미세융모들의 기부에서는 고배율 하에서 pinocytotic vesicle들이 관찰되었고 때로 세포의 분비물을 세포 밖으로 방출하는 모습도 관찰되었다. 세포들의 상부세포질에는 많은 수의 mitochondria가 있었고, 때로 분비과립과 lysosomd들이 존재하기도 하였다. 이들보다 아래에는 잘 발달한 골지체와 과립소포체(RER)들이 있었다. 이 부위에서 분비과립들이 많이 형성되어 있는 모습이 세포에 따라 관찰되었고, 그 아래에 즉, 각 세포의 하반부 세포질에 상하로 긴 핵이 관찰되었다. 세포의 기부 원형질막은 상부 세포질 내로 깊게 그리고 수없이 많이 주름을 이루고 있어 인접한 세포와의 경계를 구분할 수 없을 정도였다. 기저막의 아래에는 근육다발과 색소세포들이 결합조직 내에서 관찰되었고, 정자낭의 외막은 큰 액포로 인하여 세포질들이 원형질막 주변으로 밀려나 있는 특이한 세포들로 이루어져 있었다. 정자낭의 기능은 정자를 일시 저장하며 정자낭 상피에서 분비되는 소화액들로 정자를 일차적으로 세포외 소화하고 소화되지 않은 물질들을 흡수하여 이차적으로 세포내소화하는 것으로 생각된다.
