Cipangopaludina Chinensis Research Articles

A New, Old Method for Assessing Measurement Error in Both Univariate and Multivariate Morphometric Studies

A new approach to assessing percent measurement error (%ME), using an old sta- tistical technique (Model II Analyses of Variance and Covariance: ANOVA/ANCOVA), was developed using both weight and linear measurements made three times each on 87 freshwater snails (Cipangopaludina chinensis; Vivipariidae). Variability of each measurement, as well as co- variability between pairs of measurements, was partitioned into among- and within-snail (i.e., measurement error) components. The %ME varied by two orders of magnitude across the ten measurement variables considered. Shell weight had the lowest %ME (0.059%), while body whorl height had the highest (3.88%). There was a low correlation between %ME and the among-snail coefficient of variation for each variable (r = -0.28; P > 0.20). Within-snail correlations between pairs of measurement variables were uniformly low (r,ilhin ' 0.20), while among-snail correlations were generally very high (r = 0.74 to 0.99) due to the large size range of snails in the sample. In any morphometric study, if %ME is found to be high for a particular variable, it should either be deleted from the study or remeasured a number of times on every individual to be included in the dataset. (Measurement error; morphhometrics; model II ANOVA/ANCOVA.)

Studies on Echinostoma spp. in the Chungju Reservoir and upper streams of the Namhan River

The present study was performed to know the epidemiological status of echinostomiasis in the Chungju Reservoir and upper streams of Namhan River, together with an experimental study on the life history of Echinostoma hortense. The stool specimens of 169 inhabitants and 473 junior high school students from 5 different villages revealed 3 (0.5%) echinostomatid egg positive cases. E. hortense adult worms were recovered from one patient after a treatment and purgation. For the other two patients, it was presumed that one had E. hortense and another E. cinetorchis infection, based on the morphology of eggs. Five kinds of freshwater snails (168 Radix auricularia coreana, 534 Physa acuta, 144 Hippeutis cantori, 56 Cipangopaludina chinensis malleata and 125 Semisulcospira nodifila globus) examined for the cercariae of echinostomes showed negative results. Ten kinds of freshwater fishes examined for E. hortense metacercariae revealed positive rates as Misgurnus anguillicaudatus 40.5%, Odontobutis obscura interrupta 20.3%, Moroco oxycephalus 3.9%, and Coreoperca kawamebari 2.0%. In the experimental study, the metacercariae of E. hortense were infected to rats, eggs were collected from adult worms and cultivated, and miracidia were obtained. The miracidia were artificially infected to freshwater snails (R. auricularia), and cercarial shedding was studied. It was revealed that, when the snails were kept at a low temperature (24 degrees C), only 523 cercariae (on average) were produced during 24 hrs, while they were at a high temperature (30 degrees C), as many as 9,990 cercariae (on average) were shed during the same time. The experimental infection of E. hortense cercariae to freshwater fishes was successful in O. obscura interrupta 52.0%, M. anguillicaudatus 30.3%, C. kawamebari 27.0%, Cobitis lutheri 15.0%, M. oxycephalus 7.3%, Pseudogobio esocinus 4.3%, Squalidus coreanus 2.0%, Zacco platypus 1.3%, and Pungtungia herzi 1.3%. However, infection was not successful to snails, C. chinensis. It has been proved that the Chungju Reservoir and upper streams of Namhan river are endemic areas of echinostomiasis, especially of E. hortense, and snails such as R. auricularia coreana and fishes such as O. obscura interrupta, M. anguillicaudatus, and others are taking the role of first and second intermediate hosts, respectively.

Removal of Heavy Metals and Sewage Sludge Using the Mud Snail, Cipangopaludina chinensis malle at a REEVE, in Paddy Fields as Artificial Wetlands

The effects of the application of reed-sewage sludge compost on the heavy metal incorporation and the growth of young snails born from the adult mud snails, Cipanqopaludina chinensis malleata REEVE, put into submerged paddy soil were investigated. The biomass and growth of the snails in paddy soil with compost were superior to those in soil without compost. The Zn and Cu concentrations in the flesh portion of snails were extremely high as compared with those in the paddy soil surrounding the snails. This may be because snails ingest sewage sludge which is a main organic component of the composts and sewage sludge usually contains large amounts of Zn and Cu, suggesting that this type of snail may be useful in eliminating sewage sludge and Zn and Cu in paddy soil when composted sewage sludge has been applied.

Incorporation of heavy metals by the mud snail, Cipangopaludina chinensis malleata Reeve, in submerged paddy soil treated with composted sewage sludge

The biomass of newborn snails was higher in paddy soil without rice plants than in the soil with rice plants. There was an inverse correlation between shell width and concentratins of Zn and Cu in snail flesh. The Zn and Cu concentrations in snail flesh were extremely high compared with those in the paddy soil surrounding the snails, possibly because snails ingest sludge, one of the main components of the composts. These results suggest that this type of snail may be used to eliminate Zn and Cu from paddy soil when composted sewage sludge has been applied.

Distribution Of Medically Important Freshwater Snails And Larval Trematodes From Parafossarulus Manchouricus And Semisulcospira Libertina Around The Jinyang Lake In Kyongsang-Nam-Do, Korea

The Jinyang Lake is dammed up Nam River, and surrounded by Jinju city and four counties; Jinyang, Sanchong, Hadong, and Sachon in Kyongsang-Nam-Do, Korea. The area around this man-made lake have been known as an endemic focus of clonorchiasis in Korea. The present study was first aimed to know the distribution of freshwater mollusks including medically important snails, and larval trematodes shed from Parafossarulus manchouricus and Semisulcospira libertina. In addtion to above studies, water analyses in each snail habitat were carried out in order to figure out a part of their environmental factors. This malaco-ecological survey was done at the six areas around upper, middle and lower parts of the lake for 4 months, August-November, 1983. Total nine species of freshwater mollusks were collected throughout the study: 4 species of gastropods; Semisulcospira libertina, Cipangopaludina chinensis, Parafossarulus manchouricus and Radix auricularia, and 5 species of bivalves; Unio douglasiae, Anodonta woodiana, Lamprotula gottschei, Corbicula fluminea and Limnoperma lucustris. Out of nine species of freshwater mollusks, three species of gastropods; S. libertina, P. manchouricus and R. auricularia were medically important in terms of the transmission of digenetic trematodes to humans. P. manchouricus and R. auricularia were mainly collected from the shallow ponds and the irrigation channels with the muddy basin, but S. libertina and the bivalves were only collected from the stream of Nam river where the gravels and rocks were dominant. The levels of dissolved oxygen(D.O.) and biochemical oxygen demand (B.O.D.(5)) of the water specimens sampled from the study areas ranged from 6.0 to 9.6 ppm and from 0.4 to 1.6 ppm respectively. As a result, it is considered that water system around the Jinyang Lake might be relatively clean without any heavy pollution of aquatic microorganisms and organic materials during the period of this study. On the other hand, eight metalic constituents from the water samples were also assayed, and all metalic ions detected were remarkably low below the legal criteria. However, calcium ion in the water samples from the habitats of P. manchouricus was considerably higher than others. Infection rates of digenetic trematodes in the snails were 6.9 % in P. manchouricus and 4.8 poercent in S. libertina, respectively. P. manchouricus snails harboring with the cercariae of Clonorchis sinensis were only 0.14 % among the snails examined and other trematode cercariae except cercaria of C. sinensis were; furcocercus cercariae, cercaria of Loxogenes liberum type I and II. S. libertina snails parasitized with the cercariae of Metagonimus yokogawai were 1.5 % out of the snails examined and no cercaria of Paragonimus westermani was found in S. libertina snails in the present study. Digenetic trematode cercariae other then M. yokogawai in S. libertina snails were: Cercaria yoshidae (B type), Cercaria cristata, Cercaria innominatum, Cercaria of Centrocestus formosanus and Cercaria nipponensis.

The Natural History of an Ovoviviparous Snail, Viviparus georgianus (Lea), in a Soft-Water Eutrophic Lake

A population of the freshwater viviparid prosobranch snail, Viviparus georgianus, was studied in an eutrophic lake in western Connecticut. Male and female life spans were two and three years, respectively. Females grew longer and relatively wider than males. Shell growth of width to height was allometric and similar in pattern to another viviparid, Cipangopaludina chinensis. Growth rates were rapid after the lake warmed in spring and were negligible during winter. Mortality was relatively low for younger snails, and the death of the eldest cohort was a highly synchronized event occurring in late spring. Reproduction was semelparous. Females brooded a single batch of eggs for nine months during their third year (27-36 months old), released the young in April, and died at 38 months of age. The population demonstrated a migratory pattern which resulted in deep water winter aggregations and shallow water summer aggregations. Older males and females migrated together but the youngest cohort tended to lag behind.