• Development and Reproduction
• /
• v.9 no.1
• /
• pp.7-13
• /
• 2005

The effects of various physicochemical stimuli in parturition induction were assayed on ovoviviparous freshwater melania snails, Semisulcospira libertina libertina and S. gottschei. Both of them did not respond to $NH_4OH$ and $H_2O_2$, but showed responses to the water temperature raising, serotonin and acetylcholine. S. gottschei showed stronger responses to the stimulants in parturition induction compared with S. libertina libertina. In case of S. libertina libertina exposed to $10^{-9}M$ acetylcholine, the number of newly born larvae and juveniles per adult and juvenile parturition rate were 68 individuals and 57.5%, which were the most among experimental groups, respectively. In the parturition induction with temperature raising of $9^{\circ}C$, S. gottschei bred 113 larvae and juveniles in which juvenile parturition rate was 56.3% and $10^{-12}M$ acetylcholine also induced very high juvenile parturition rate(61.7%) and 83 larvae and juveniles. It could be concluded that the treatment of acetylcholine has a high effectiveness in the parturition induction of S. libertina libertina and S. gottschei.

• Development and Reproduction
• /
• v.4 no.2
• /
• pp.175-180
• /
• 2000

The reproductive cycle of ovoviviparous melania snail, Semisulcospira libeytina libertina was studied in the valley near Naewon Temple in Yangsan, Korea. Water temperature (WT) of the habitat ranged from 1.3$^{\circ}C$ to 22.5$^{\circ}C$ The meat weight rate (MWR) reached the maximum with the beginning of WT increase in March and the minimum in August. Monthly changes in average oocyte diameter showed the maximum (249.6$\pm$2.6 ${\mu}{\textrm}{m}$) in July and the minimum (134.3$\pm$2.8 ${\mu}{\textrm}{m}$) in December S. libertina libertina seemed to be a year-round breeder except for mid-summer and mid-winter. Two main reproductive cycle of the species could be divided into five successive stages: multiplicative (March, October), growing (April and May, November), mature (June and July, December), ovulation (August, January), parturition (September and October, March to May) and resting (September, February) stages in female and multiplicative (March, October), growing (April, November), mature (March to June, December), copulatory (July and August, January), resting (September, February) stages in male.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2002.05a
• /
• pp.327-328
• /
• 2002

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2002.08a
• /
• pp.202-203
• /
• 2002

• The Korean Journal of Malacology
• /
• v.15 no.1
• /
• pp.13-20
• /
• 1999

A horizontal starch gel electrophoresis for enzyme proteins extracted from three Korean species and one Chinese species of Semisulcospira was carried out in order to elucidate their genetic relationships. A total of 10 enzymes were employed in three different of buffer systems. Two loci from each enzyme of GAPDH, GOT, ICDH, IDH and PEP(VL); three loci from each of three enzymes, EST, PEP(LGG) and PGDH; and five loci from GPI were observed. Most of the loci in three pleurocerid species employed showed homozygous monomorphic banding patterns and some of them were specific as genetic markers between two different species. However, EST-2, PEP(LGG-3) and PGDH-1 loci in Korean S. libertina and PEP(LGG-3), PGM-1 and PGM-2 loci in Chinese S. libertina showed polymorphic banding patterns. Three Korean Semisulcospira species including S. libertina were more closely clustered in a dendrogram within the range of genetic identity values of 0.818-0.936, and these clusters were lineated with Chinese S. libertina at the value of 0.621.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2000.05a
• /
• pp.263-264
• /
• 2000

한국을 비롯하여 일본, 대만, 중국 등에 널리 분포되어 있는 다슬기(Semisulcospira libertina libertina)는 자웅이체로서 난생 또는 난태생인 것으로 알려져 있다. 우리나라에는 전국에 걸쳐 강, 호수, 연못 및 계곡 등에 널리 서식하며, 식용으로서 기호도가 높은 유용 수산자원이다. 그러나 최근에는 생활하수, 농약, 중금속 등에 의한 다슬기 서식지 오염과 행락객의 무분별한 채취로 인해 자원이 급격히 줄어들고 있다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2001.05a
• /
• pp.381-382
• /
• 2001

다슬기 (Semisulcospira libertina libertina)는 식용으로 기호도가 높고 유용 수산자원으로서 개발 가치가 높으나 성장이나 자원량에 관한 기초 생물학적인 조사는 충분히 이루어지지 않고 있다. 최근에는 중금속, 농약 등에 오염될 가능성이 있어 자연산 다슬기의 식용 가능성 여부가 불투명한 상태에 이르고 있으며, 자연자원도 급격히 줄어 들고 있는 실정이다. 따라서 다슬기의 종묘생산 및 양식기술 개발에 대한 관심이 고조되고 있으며, 이 종에 대한 번식생물학적인 연구 (Chang et al., 2000)가 진행되고 있으나, 다슬기 종묘의 성장 상황에 대한 기준 자료는 찾아보기 힘들다. (중략)

• Genomics & Informatics
• /
• v.19 no.3
• /
• pp.32.1-32.10
• /
• 2021

Semisulcospira libertina, a species of freshwater snail, is widespread in East Asia. It is important as a food source. Additionally, it is a vector of clonorchiasis, paragonimiasis, metagonimiasis, and other parasites. Although S. libertina has ecological, commercial, and clinical importance, its whole-genome has not been reported yet. Here, we revealed the genome of S. libertina through de novo assembly. We assembled the whole-genome of S. libertina and determined its transcriptome for the first time using Illumina NovaSeq 6000 platform. According to the k-mer analysis, the genome size of S. libertina was estimated to be 3.04 Gb. Using RepeatMasker, a total of 53.68% of repeats were identified in the genome assembly. Genome data of S. libertina reported in this study will be useful for identification and conservation of S. libertina in East Asia.

• The Korean Journal of Malacology
• /
• v.29 no.1
• /
• pp.83-85
• /
• 2013

Size-mass relationships were estimated for 4 species belonging to genus Semisulcospira from the Guem River, Korea. These 4 freshwater snail species: Semisulcospira libertina, Semisulcospira coreana, Semisulcospira gottschei, and Semisulcospira forticosta. Between June and November 2011, samples were caught by dredge (mesh size 10mm of multifilament nylon, total length 4.35 m) at depths of < 2 m. Estimates of for parameter b of the size-mass relationship (W = $aSH^b$) ranged between 2.0072 (Semisulcospira libertina) and 2.3463 (Semisulcospira gottschei).

• The Korean Journal of Malacology
• /
• v.25 no.2
• /
• pp.145-151
• /
• 2009

The ultrastructural changes in germ cells during oogenesis of the melania snail, Semisulcospira libertina libertina have been investigated by light and electron microscopy. The ovary is located on the surface of the hepatopancreas in the spiral posterior region. The ovary exhibited greenish color in the gonadal mature season. The ovary was composed of a number of oogenic follicles. Oogenesis was divided into five stages with histological features: (1) oogonia, (2) previtellogenic, (3) initial vitellogenic, (4) active vitellogenic, and (5) mature stages. Oogonia were oval in shape, $4-6\;{\mu}m$ in diameter, and had a large nucleus. Previtellogenic oocytes were about $20\;{\mu}m$ in diameter and the cytoplasm reacted with hematoxylin in H-E satin. Initial vitellogenic stage, oocytes were $60-80\;{\mu}m$ in diameter, and small yolk granules of low electron density are scattered in the cytoplasm. Oocytes in the initial vitellogenic stage were connected with ovarian follicle by egg stalk. Active vitellogenic oocyte were $100-120\;{\mu}m$ in diameter. Electron density, size and quantity of yolk granules that are distributed in the cytoplasm have increased from the previous stage. Result of TEM observations, the oocyte contains well-developed Golgi complex, endoplasmic reticula and tubular mitochondria in the cytoplasm. Cytoplasm of mature oocyte was filled with proteinaceous yolk globules of high electron density. In this stage, the length of microvilli in the egg envelope was approximately $1.1\;{\mu}m$.