| Home | E-Submission | Sitemap | Contact us |  
top_img
Korean J Parasitol > Volume 23(1):1985 > Article

Original Article
Korean J Parasitol. 1985 Jun;23(1):79-86. English.
Published online Mar 20, 1994.  http://dx.doi.org/10.3347/kjp.1985.23.1.79
Copyright © 1985 by The Korean Society for Parasitology
Experimental studies on the second intermediate hosts of Clonorchis sinensis IV. Observations on the fate of metacercariae of Clonorchis sinensis in the fish host, Cultriculus eigenmanni
Jae Ku Rhee,Byeong Kirl Baek and Ho Il Lee
Department of Veterinary Parasitology, Jeonbug National University, Jeonju 520, Korea.
Abstract

In order to judge appropriately the suitability as the second intermediate host of Clonorchis sinensis, the present experiments were proposed to survey the metacercaria of C. sinensis in the fish host, Cultriculus eigenmanni, in the field, and to observe, by experimental infection of the fish with Clonorchis cercaria, the penetrating ability of the cercaria, maturity, the process of degeneration and extinction, and infectivity of the metacercaria. The following is a brief summary of the leading facts gained through the experiments. All the ten fish (mean body weight 13.4 ± 3.43 g) which were caught in Ok-ku irrigation reservoir were infected with the metacercariae and the average number of the metacercariae found in the fish body/gram was 4.55. The fish was easily subject to invasion of the cercaria, and the examination of the cercariae after having the fish infected disclosed that 24 hours after the infection, all of the cercariae formed their cysts in muscle and the metacercariae kept growing, that 7 days later the metacercariae were found folding their bodies twice, and that in 15 days the characteristic structure of the metacercariae was complete and made a vigorous rotary movement intermittently. In the case of control fish, Pseudorasbora parva, both penetrating ability of the cercariae and the infective degree of the metacercariae to control host were stronger as compared with the fish host because that the control fish had higher suceptibility to C. sinensis. Afterwards, the metacercariae in the fish host came to a state of maturity and beyond this stage some metacercariae started the process of degeneration and extinction in as early as 30 days, and as more days elapsed, mortality of the metacercariae was not uniformly increased but difference of mortality appeared to be according to the individual of fish host. That is, in 390, 540 and 586 days, all of the metacercariae in the fish hosts became dead, meanwhile almost all of those found in the fish host of 596 days after the infection survived (mortality; 8.51 percent). Percentage of orally administered metacercariae developing to maturity in rabbit is 10.46 percent in the last case. As the days were progressed the shapes of the metacercariae in the fish host tended to change from ellipsoid to almost round shapes, the length became shorter while the width was wider. The results shown above revealed that C. eigenmanni was, though it could not be proper host than P. parva, suitable as the second intermediate host in addition to our previous observation results.

Figures


Fig. 1
Chronological change in ratio of length to width of Clonorchis metacercariae detected in Cultriculus eigenmanni.


Figs. 2-9
Figures given are of raw temporary specimens of the metacercariae of Clonorchis sinensis detected in the fish body, Cultriculus eigenmanni. And, magnification on figures 2, 3 and 6 is 200 times and remainder is 400 times.

Fig. 2. The oval cyst of 72 hours after the infection measured 100.7×90.1µm and has a second cyst layer prodeced by the host. The pigmented eyespots and the excretory bladder are obviously observed.

Fig. 3. Its internal structure is impossible to observe except for the eyespots from the metacercaria (103.0×87.0µm) which is degenerated into death, 3 days after the infection.

Fig. 4. A grayish-white space is visible between the body of dead metacercaria and the cyst wall whereas its internal structure is impossible to observe, and the cyst of 7 days after the infection measured 156.3×132.5µm.

Fig. 5. Internal organs are seen from the normal metacercaria alive (139.2×98.0µm), 30 days after the infection.

Fig. 6. Large type of the normal metacercaria alive measured 238.5×212µm and its internal structure is visible, 40 days after the infection.

Fig. 7. The cyst (129.0×66.0µm) is exceedingly diminished in size with only degenerated excretory corpuscles left, 390 days after the infection.

Fig. 8. A grayish-white space is visible between the body of bent metacercaria and the cyst wall whereas its internal structure is impossible to observe owing to degenerated reddish-brown pigment masses. The almost round cyst measured 127.2×137.8µm, same case as the above.

Fig. 9. The almost round metacercaria measured 127.0×135.0µm and normal structure and a vigorous rotary movement can be observed, same case as the above.


Tables


Table 1
Distribution of digenetic trematode metacercariae in ten Cultriculus eigenmanni*


Table 2
Chronological status of Clonorchis metacercariae detected in Cultriculus eigenmanni


Table 3
Percentage of orally administered Clonorchis metacercariae developing to maturity in rabbits

References
1. Chun SK. [Studies On The Experimental Mode Of Infections Of Clonorchis Sinensis: II. Experimental Infection Of Clonorchis Sinensis Cercaria To Fry Of Fresh Water Fishes]. Korean J Parasitol 1964;2(3):137–147.
 
2. Chun SK. [Studies on the experimental mode of infections of Clonorchis sinensis: III. Studies on the wormicidal effect of external mucous substance of some fresh water fish on the larva of Clonorchis sinensis]. Korean J Parasitol 1964;2(3):148–158.
 
3. Kobayashi H. Acta Medicinalia in Keijo 1928;11(2):109–124.
4. Rhee JK. [Experimental studies on the second intermediate hosts of Clonorchis sinensis: III. Observations on the relationship between clavate cells of epidermis and infectivity of metacercariae of Clonorchis sinensis in fresh-water fish]. Korean J Parasitol 1974;12(2):101–110.
 
5. Rhee JK, Baek BK, Ahn BZ, Park YJ. [The Wormicidal Substances Of Fresh Water Fishes On Clonorchis Sinensis: I Preliminary Research On The Wormicidal Substance From Mucous Substance Of Carassius Carassius]. Korean J Parasitol 1979;17(2):121–126.
 
6. Rhee JK, Baek BK, Ahn BZ, Park YJ. [The Wormicidal Substances Of Fresh Water Fishes On Clonorchis Sinensis: II. Preliminary Research On The Wormicidal Substances From Mucous Substances Of Various Fresh Water Fishes]. Korean J Parasitol 1980;18(1):98–104.
 
7. Rhee JK, Kim PG, Baek BK, Lee SB, Ahn BZ. [Experimental Infection Of Clonorchis Sinensis To Cyprinus Carpio Nudus]. Korean J Parasitol 1983;21(1):11–19.
 
8. Rhee JK, Kim PG, Baek BK, Lee SB, Ahn BZ. [The Wormicidal Substance Of Fresh Water Fishes On Clonorchis Sinensis: Iv. Preliminary Research On The Wormicidal Substance From Mucus Of Cyprinus Carpio Nudus]. Korean J Parasitol 1983;21(1):21–26.
 
9. Rhee JK, Lee SB, Ahn BZ. [The Wormicidal Substance Of Fresh Water Fishes On Clonorchis Sinensis V. Purification And Chemical Characterization Of Clonorchicidal Substance From Epidermal Mucus Of Cyprinus Carpio]. Korean J Parasitol 1984;22(1):127–134.
 
Editorial Office
Department of Molecular Parasitology, Samsung Medical Center, School of Medicine, Sungkyunkwan University,
2066 Seobu-ro, Jangan-gu, Suwon 16419, Gyeonggi-do, Korea.
Tel: +82-31-299-6251   FAX: +82-1-299-6269   E-mail: kjp.editor@gmail.com
About |  Browse Articles |  Current Issue |  For Authors and Reviewers
Copyright © 2022 by The Korean Society for Parasitology and Tropical Medicine.     Developed in M2PI