Occurrence of Clinostomum complanatum in Aphanius dispar (Actinoptrygii: Cyprinodontidae) collected from Mehran River, Hormuzgan Province, South of Iran

OBJECTIVE

To investigate the possibility of Aphanius dispar (A.dispar) acting as intermediate host for Clinostomum complanatum (C. complanatum), from Mehran River, Hormuzgan Province of Iran.

METHODS

During a biological study of A. dispar in Mehran River, Hormuzgan Province, South of Iran, a total of 97 fish specimens were collected in 24 January 2006.

RESULTS

4 specimens (4.12%) including 1 male and 3 female were found infected with C. complanatum metacercaria. These metacercaria were coiled in the epiderm on the body surface of infected fishes. The infection is known as yellow spot disease. The parasite abundance, intensity and prevalence were 0.05%, 1.25% and 4.12%, respectively. The infection was higher in females than males.

CONCLUSIONS

To the best of our knowledge, this is the first report on occurrence of C. complanatum metacercaria in A. dispar in Iran.

Experimental infection with Paragonimus heterotremus metacercariae in laboratory animals in Manipur, India

This study was aimed to find out the host-parasite relationship between Paragonimus heterotremus isolated as metacercariae from mountain crabs, Indochinamon manipurensis, in Manipur, India and laboratory animals such as puppies, albino rats, Swiss mice, guinea pigs, and rabbits, as experimental animals. The animals were fed with the metacercariae. Infected animals were sacrificed 35 to 430 days after feeding to recover worms, which were used to determine the developmental stages. Adult worms (n = 14) were recovered from 3 puppies > or = 70 days after feeding and immature worms (n = 25) were recovered from 2 other puppies 35 or 43 days after infection. The infection rate in puppies was 100%. Juvenile worms were recovered from 3 of 13 rats: 1 of 11 rats whose viscera and cavities were examined and both of two rats whose muscles were examined. Rats were not a suitable animal model for pulmonary infection with P. heterotremus. Mice, guinea pigs, and rabbits were also found to be insusceptible to pulmonary infection with P. heterotremus.

Seasonal variation of metacercariae in cyprinoid fish from Kwae Noi Bamroongdan Dam, Phitsanulok Province, northern Thailand

Abstract. A seasonal investigation of the occurrence of metacercariae in cyprinoid fish was conducted at the Kwae Noi Bamroongdan Dam, Phitsanulok Province, northern Thailand during December 2008-August 2009. A total 361 cyprinoid fish from 10 species were examined by artificial digestion method evaluating for metacercariae. The metacercariae determined were Haplorchis taichui, Haplorchis pumilio, Haplorchoides sp and Centrocestus caninus. The prevalence of metacercariae ranged from 76.5% to 82.6%, with an intensity of infection of 23.4 to 36.6. H. taichui, Haplorchoides sp and C. caninus had the highest prevalence in the cool season, while H. pumilio was more prevalent during the hot season. The highest infection prevalence (100%) was seen in Rasbora metallicus, Barbodes gonionotus and R. metallicus. No significant differences in the type of metacercariae were found between seasons, indicating year-round infestation of cyprinoid fish.

Infection dynamics and molecular identification of metacercariae in cyprinoids from Chiang Mai and Sakon Nakhon Provinces

The infection dynamics of metacercariae were assessed in cyprinoid fish (cyprinoids) from Chiang Mai and Sakon Nakhon Provinces, Thailand, during October 2008 to September 2009. The samples were collected during 3 seasons from rivers and local markets. Metacercarial infection was determined by acid-pepsin digestion and confirmed using HAT-RAPD PCR method. Thirteen and 16 species of cyprinoids were collected from Chiang Mai and Sakon Nakhon with overall prevalences of metacercarial infection of 84.5 and 47.6%, respectively. Haplorchis taichui, Haplorchoides sp, and Centrocestus caninus were found in Chiang Mai and 4 species of metacercariae: H. taichui, Haplorchoides sp, O. viverrini and an unknown trematode species in Sakon Nakhon. H. taichui and Haplorchoides sp metacercariae in 3 species of cyprinoids (Henicorhynchus siamensis, Cyclocheilichthys armatus, Amblyrhynchichthy truncatus) had the highest prevalence (100%) in Chiang Mai, while the highest prevalence (100%) of metacercaria in Sakon Nakhon was Haplorchoides sp in 1 species of cyprinoids (Cyclocheilichthys armatus). The overall prevalence from Chiang Mai Province was highest in the rainy season (95.6%), lower in the hot-dry season (88.1%) and lowest in the cool season (72.5%). In Sakon Nakhon Province the highest prevalence was in the hot-dry season (52.7%), and lower in the rainy and cool season, 44.4% and 43.5%, respectively. The HAT-RAPD profiles confirmed the identity of metacercariae and adult stage of H. taichui, Haplorchoides sp, C. caninus and O. viverrini.