• Title/Summary/Keyword: radula

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First Record of the Velvet Snail, Coriocella jayi (Littorinimorpha: Velutinidae) from Korea

  • Yucheol Lee;Damin Lee;Jina Park;Joong-Ki Park
    • Animal Systematics, Evolution and Diversity
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    • v.40 no.2
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    • pp.130-134
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    • 2024
  • The family Velutinidae is found in various intertidal and subtidal habitats worldwide including Arctic and Antarctic seas. They are characterized by possessing a fragile shell that is partially or entirely covered by the mantle. Eight valid species of the genus Coriocella have been reported mostly in the Indo-West Pacific. Here we report Coriocella jayi Wellens, 1996 from Korean waters for the first time and describe details of their external morphology and radula characteristics using scanning electron microscopy, and provide the mtDNA cox1 sequence as a DNA barcode sequence information. This species is distinguished from other congeneric species by having six cylinder-shaped tubercular lobes of their dorsal part of mantle body and mantle color. Phylogenetic tree using the mtDNA cox1 sequence data shows that two Coriocella species (C. jayi and C. nigra) are grouped as their respective sister among Velutinidae species, and these relationships are strongly supported by 100% bootstrap value. Despite the morphological similarities, further investigation will be needed to confirm whether the African and Korean populations can be justified as the same species with a disconnected distribution range, or represent morphologically similar but two distinct species.

Observations of Boring Behaviour and the Drilling Mechanism of Lunatia fortunei (Gastropoda: Naticidae) in Western Korea

  • Chung, Ee-Yung;Kim, Sung-Han;Back, Yong-Hae
    • The Korean Journal of Malacology
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    • v.27 no.3
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    • pp.253-259
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    • 2011
  • Boring behaviour and drilling mechanism were investigated by visual observations. In this study, of two kinds of holes (the outer and inner holes) which are formed by drilling of boring gastropod Lunatia fortunei (Naticidae), the diameters of the outer holes are broader and larger than those of the inner holes, and their holes look like the crater in shape, as seen in all valves of bivalves bored by Naticidae species. Two kinds of glands (the accessory boring gland and accessory salivary gland) on the foots of boring gastropods have been investigated. Of them, it has been confirmed that only the accessory salivary glands on the foots secreted sulphuric (acidic) components in the mucus (secretion), while the accessory boring glands on the foots did not secrete their components. In this study, we confirmed that L. fortunei possess the accessory boring gland on the foot, as seen in most species in Naticidae. Accoeding to the results of the experiment of the blue litmus paper tests of the mucus (secretions) secreted from the accessory boring gland the color of the blue litmus paper did not turn red in color because chemical components of mucus (secretion) secreted from the accessory boring gland on the foot of L. fortunei (boring gastropod) were not acidic components. It is supposed that the mucus, which is secreted from the accessory boring gland, contained gelatin-like substances or enzymes without acidic components, as already reported in Naticidae species. Therefore, these substances may be involved in softening the surface of the valves of M. veneriformis. Consequently, it is assumed thar L. fortunei bores holes through the shells of molluscs by means of following 3 methods: (1) a softening of the calcareous shells of M. veneriformis with chemical secretions (including gellatin-like substances or enzyme except for acidic components) from the accessory boring glands, (2) mechanical rasping with the radula, (3) a combination of both. In this study, particularly, acidic components, which are involved in softening the surface of the shells, are not associated with the boring mechanism of L. fortunei because chemical acidic components were not detected in the mucus (secretion), as found in Naticidae species.

Fungal Flora of Ullung Island (I) - on Some Corticioid Fungi - (울릉도의 근류상 (I) - 수 종 고약균류에 관하여 -)

  • 정학성
    • Journal of Plant Biology
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    • v.34 no.1
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    • pp.77-90
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    • 1991
  • Fresh fungi were obtained during collection trips to Ullung Island in October, 1989, and August, 1990. Among them, some corticioid fungi were identified. Ten fungi were confirmed new to Korea and are recorded here with descriptions. They are Athelia epiphylla, Grandinia alutaria, G. gran.utosa, G. stenospora. Cylindrobasidium evolvens. Hyphoderma rlldula, H setigerum, Hypochnicium eichleri, Trechispora Illbo-ochracea, and T. farinllcea.nllcea.

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Study on Radulae of Seven Species of the Family Pleuroceridae in Korea (한국산 다슬기 과 7 종의 치설 연구)

  • 고정호;이준상;권오길
    • The Korean Journal of Malacology
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    • v.17 no.2
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    • pp.105-115
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    • 2001
  • These studies were conducted to compare the external radulae of seven species (Semisulcospira gottschei, S. coreana, S. forticosta, S. tegulata, S. ibertina, Koreanomelania nodifila and Koreoleptoxis globus ovalis) of freshwater snails in three genera of the family Pleuroceridae in Korea. Under a microscope of 100 magnifications, observation of seven species can be distinguished sharply between three genera of Semisuicospira, Koreanomelania and Koreoleptoxis, and the morphological characters of radulae can be used as taxonomic tool in genus level of Pleuroceridae. Besides SEM photograph of the radulae based on the morphological characters in seven species can be verified a new criteria for classification of genus' unit grade in accord with firsthand drawing sketch under a microscope of 100 magnifications. But it is difficult that all of the species can be detected sharply the difference of interspecies by comparisons of radulae in the family Pleuroceridae in Korea. Therefore, the morphological characters of radulae can not be set a criteria for classification of species level.

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Physiological and Ecological Characteristics of the Apple Snails (왕우렁이 (apple snails)의 생리.생태적 특성에 관한 연구)

  • Lee, Sang-Beom;Koh, Mun-Hwan;Na, Young-Eun;Kim, Jin-Ho
    • Korean Journal of Environmental Agriculture
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    • v.21 no.1
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    • pp.50-56
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    • 2002
  • This experiment was carried out to obtain some information about overwintering, physiological and ecological characteristics of apple snails. Another purpose of this experiment was to characterize an appetite for rice plants by apple snails and to elucidate their choice of fresh green ones (vegetables, some other crops, weeds in rice fields). The freshwater snails were found with higher population at sites abundant organic compounds such as plant debris and at regions with high temperature. They also prefer calcium-rich water. This is a naturally occurring process. Apple snails were exceptionally veil-adapted to the south regions of Korea, especially Janghang, Jangseong and Haenam, even if the temperature of winter season is cold below 0$^{\circ}C$. Apple snails were not very selective in their food choice and eat almost everything available in their environment. A snail have something called a radula in its mouth for grinding up its food. A apple snail also chews on fruits and young succulent plant barks. In case of reproduction. apple snails deposit about 157$\sim$784 (average of 321 eggs) milky white to pale orange colored eggs above the waterline. In approximately every 22.4 seconds a new egg appears. The total time needed to deposit a egg mass varies from 58 minutes$\sim$4 hours 13 minutes. Apple snails reproduct actively from May to June and from September to October. An appetite of apple snails for rice plants was the different depending on their size and glowing stage for rice plants. Apple snails had a great appetite of rice plants as well as dropwort, tomato, cabbage, radish, aquatic plants etc. They preferred to eat young rice plants and drastically quit eating rice plants of over 40 cm in height. Thus considering the food preference of apple snail for various plants including rice, they were thought to be a potentially strong predator in fields, especially, at regions with warmer winter.