ISSN : 1225-3480
A study on the seasonal changes of the benthic macroinvertebrate community was performed on the intertidal rocky shores ao eastern coast of Cheju island and U-do throughout four seasons from october 1991 to August 1992. The macroinvertebrates were composed of 10 phyla, 18 classes, 39 orders, 94 families and 201 species. the number of speecies were 183 in summer, 147 in autumn, 138 in spring and 94 in winter, respectively. The total wpecies collected throuhout the study period were 193 species in U-do and 151 species in the eastern coast of Cheju Island. Nodilittorina exigua was the most dominant species in all seasons, followed by Monodonta neritoides in spring, autumn and winter, and pollicipes mitella in summer. U-do was higher in species diversity and richness and lower in evenness than the eastern coast. Species diversity and richness were higher in summer than any other seasons in lower intertidal zones. Community dominance indices, however, were significantly higher in upper intertidal zones than in lower intertidal zones.
Field investigations were made in 1991 and 1992 in Kwangju and the western and central Chonnam area to determine the distribution of Lymnaea viridis, the intermediate host of Fasciola hepatica, and to study their life history during the different seasons. It had a wide distribution, existing all over the places, and the principal habitats of the snail were rice paddies. The life cycle was determined by making frequent visits to a series of habitats. The snsils began to produce egg masses in April, and egg production was the highest in May and June. Egg laying was continued but decreased in summer. There was sudden decrease in egg production in October when the temperature was below 2<TEX>$0^{\circ}C$</TEX>. The number of snails in July. Under the unfavourble conditions the snail either crawle up on the snail to aestivation. At low temperature below 8<TEX>$^{\circ}C$</TEX> the snails hibernated inthe mud of the habitat. It was found in some habitats thao the snails were loving together with L. auricularia and Physa s pp. which indicates the neccessity of differentiation among them.
한국 해산 중복족류에 대한 분류학적 연구의 일환으로 1971년 9월부터 1991년 10월까지 전국 해안 34개 지점으로부터 채집된 나사고둥 상과, 배고둥 상과, 개도지 상과, 위고둥 상과에 속하는 표본들을 대상으로 동정, 분류한 결과 다음와 같은 9종의 한국 미기록종을 얻었기에 도판과함께 디들 종을 새로이 재기재하였다: Kuuosiola fascialis (Menke, 1828), Neohaustator andenensis (Otuka, 1934), Iphinoe unicarinatus(Broderip & Sowerby, 1829), Turritropis turrita Habe, 1962, Calyptraea morbida(Broderip & sowerby, 1829)Turritropis turrita Habe, 1962, Calyptraea morbida(Reeve, 1859), Crepidula onyx (Sowerby, 1824), Primovula frumentum (Sowerby, 1828), Erosaria helvora(Linne, 1758), Reticutriton tenuiliratus(Lissschke, 1873).
Inthe prisent paper, we report the study of Korean epitoniid which were collected from12 localities of Korean waters during the span of August 1982 to May 1992. Upon identification of these specimins and riview of the provious ricords, Korean Epitoniidae were found to be composed of 12 species in 10 genera, Among them, following 5 species in 4 genera were turned out to be new to the Korean malacofauna and redescribed with illustrations: Viciniscala liliputana (A. Adams, 1861), Mazescala casta(Sowerby, 1844).
Clams were collected from mouth part of Mangeong Gang(river) of which heavy metals were heavily contaminated. Scapharca subcrenata, one of the clams, were fed to mice for 1-2 months with regular food stuffs. Eventhough difference of body weight was recognized between the experimental group and normal diat group, accumulation of heavy metals examined, cadmium was found 1.16 <TEX>$\mu\textrm{g}$</TEX>/gm in liver, 3.31 <TEX>$\mu\textrm{g}$</TEX>/gm in kidney and 0.21 <TEX>$\mu\textrm{g}$</TEX>/gm in blood of experimental group at 60th day, whereas 0.14 <TEX>$\mu\textrm{g}$</TEX>/gm, 0.35<TEX>$\mu\textrm{g}$</TEX>/gm and 0<TEX>$\mu\textrm{g}$</TEX>/gm respectively in normal diet group ate tje same period. No specific histo pathological finding was found in brain and kidney, although slighr fatty change and focal necrosis were found in liver tissues of the experimental group in second month.
동양달팽이 (Nesiohelix samarangae)는 동양달팽이속(Nesiohelix)에 속하는 종으로 한국에서 동양？팽이속으로는 유일하게 발견되는 종이다. 본 실험에서는 동양달팽이의 웅성생식기관의 각 부분 즉, 난정소(ovotestis), 양성관(hermaphrodite duct), 수정실(fertilization chamber), 전립선(prostate), 수정관(vas deferens), 상음경(epiphallus), 음경(penis)등의 배열 상태를 관찰하고 이들에 대한 광학현미경적 관찰을 위해 Hematoxylin- Eosin염색과 Mallory 염색을 실시하였다. 난정소(ovotestis)는 많은 수의 선포(acini)로 이루어져 있으며 각 선포는 배상피세포층(germinal epithelial cell layer)과 영양세포(nurse cell), 생식세포(gamete cell)들로 이루어져 있었다. 선포(acini)는 원주상피로 덮여있었다. 양성관(hermaphrodite duct)은 가늘고 긴 관으로 내벽은 섬모입방상피세포와 얇은 결합조직층으로 이루어져 있었으며 내강은 농축된 정자로 가득 차 있었다 . 수정관(fertilization chamber)은 3개의 도관이 결합조직에 의해 둘러싸인 형태로 이루어져 있었다. 도관의 상피세포는 뚜렷한 위중층섬모원주세포로 되어 있었다. 전립선(prostaoe)은 분비기능을 가진 것으로 사료되는 세포들과 실제 분비가 일어나는 실(chamber)로 이루어져 있었으나 다른 염색법 또는 전자현미경적 관찰에 의해 다른 구조들의 존재유무를 확인 해야할 것으로 사료된다. 실(chamber)은 분비포로 보이는 세포들과 접해 있었다. 수정관(vas deferens)은 결합조직으로 이루어진 근육질의 두꺼운 벽을 가지고 있었으며 내강은 돌출부위에 의해 4부분으로 갈라져 있었다. 내강에 연한 상피는 원주세포로 되어 있었다. 상음경(epiphallus)의 벽은 근섬유 다발은 벽의 외곽으로 갈수록 밀도가 높아졌다. 상부에 내강과 연결되는 함입구조(groove)를 가지며, 내강에 연한 상피는 섬모가 없는 원주세포로 이루어져 있었다. 음경(penis)은 근섬유가 산재된 두꺼운 벽을 가졌으며 상음경보다 굵은 원통형이었다. 내강은 많은 돌출부에 의해 복잡하게 나뉘어 있으며 상피세포는 원주 세포로 이루어져 있었고 섬모는 관찰되지 않았다. 내강 내의 분비물과 세포의 형태로 보아 내강상피세포는 분비기능을 가진 것으로 사료된다.
