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Jong-yil Chai - One of the best experts on this subject based on the ideXlab platform.

  • Morphological and Molecular Identification of Stellantchasmus dermogenysi n. sp. (Digenea: Heterophyidae) in Thailand.
    Korean Journal of Parasitology, 2019
    Co-Authors: Chalobol Wongsawad, Pheravut Wongsawad, Nattawadee Nantarat, Preeyaporn Butboonchoo, Jong-yil Chai
    Abstract:

    We tried a series of morphological and molecular approaches to identify a new species of Stellantchasmus (Digenea: Heterophyidae) originating from the wrestling half-beaked Fish, Dermogenys pusillus of Thailand. Adult worm samples of the new species were recovered from hamsters experimentally infected with the metacercariae from D. pusillus in Thailand. Two isolates (Thai and Korean) of Stellantchasmus falcatus were used as comparative control groups. Worm samples of 3 Stellantchasmus groups were morphologically observed and molecularly analyzed with the mitochondrial cytochrome c oxidase 1 gene. The morphological characteristics of S. dermogenysi n. sp. are similar to S. falcatus originating from Brackish Water Fish, but minor difference was noted including the absence of the prepharynx, position of the ovary near the ceca end, smaller body size, and shorter esophageal length. A phylogenetic tree derived from neighbor-joining and maximum-likelihood methods suggests that S. dermogenysi n. sp. is separated from S. falcatus supported by high bootstrap values. The relative divergences persist between these host-specific trematodes, which we suggest should be recognized as 2 distinct species. Comparisons of S. dermogenysi n. sp. with S. falcatus isolated from mullets in Thailand and Korea indicate a genetic divergence of mitochondrial DNA of 19.4% and 21.7%, respectively. By the present study, a new species, Stellantchasmus dermogenysi n. sp. (Digenea: Heterophyidae), is proposed in Thailand based on molecular evidences, in addition to minor morphological differences between S. falcatus and the new species.

  • Heterophyid trematodes recovered from people residing along the Boseong River, South Korea.
    Acta Tropica, 2015
    Co-Authors: Jong-yil Chai, Bong-kwang Jung, Eun-hee Shin, Jae-lip Kim, Deok Gyu Kim, Hyemi Lim, Keon Hoon Lee, Mok Ryeon Kim, Sun Jin Han, Jae Hyun Yeom
    Abstract:

    Abstract We conducted an epidemiological survey to determine the status of heterophyid fluke infections among people residing along the Boseong River, Gokseong-gun, South Korea (= Korea) from October 2011 to February 2012. Fecal specimens were collected from 115 (male 51, female 64) people and examined for intestinal helminth eggs using the Kato-Katz thick smear technique. The eggs of Metagonimus yokogawai together with other Metagonimus spp. were detected in 28 (24.3%) cases. Eleven egg positive people were treated with 10 mg/kg praziquantel followed by MgSO 4 purging in order to recover the adult flukes. Whole consecutive diarrheic stools were collected individually 4–5 times. Adult flukes recovered were 66,499 specimens (6045.4/positive case) of M. yokogawai , 343 (38.1) of Metagonimus miyatai , 3293 (299.4) of Metagonimus takahashii , 81 (20.3) of Heterophyes nocens , 6 (3.0) of Heterophyopsis continua , and 1 (1.0) of Stictodora fuscata . The results indicated that the surveyed area is a highly endemic area of metagonimiasis (three Metagonimus species) with low-grade mixed infections of 3 other heterophyid flukes. The infected people experienced variable degrees of gastrointestinal discomfort and indigestion. They consumed raw freshWater and Brackish Water Fish, including sweetFish and mullets. It is strongly recommended that people residing in the survey area avoid eating raw Fish to prevent M. yokogawai and other heterophyid infections.

  • four human cases of acanthotrema felis digenea heterophyidae infection in korea
    Korean Journal of Parasitology, 2014
    Co-Authors: Jong-yil Chai, Jae-lip Kim, Min Seo
    Abstract:

    Acanthotrema felis is an intestinal trematode of cats originally reported from the Republic of Korea. Only 1 human case infected with a single adult worm has been previously recorded. In the present study, we report 4 human cases infected with a total of 10 worms recovered after anthelmintic treatment and purging. All 4 patients reside in coastal areas of Jeollanam-do, Korea, and have consumed Brackish Water Fish including the gobies, Acanthogobius flavimanus. The worms averaged 0.47 mm in length and 0.27 mm in width, and had 3 sclerites on the ventrogenital sac; 1 was short and thumb-like, another was long and blunt-ended, and the 3rd was long and broad-tipped. They were identified as A. felis Sohn, Han, & Chai, 2003. Surveys on coastal areas to detect further human cases infected with A. felis are required.

  • A case of Diphyllobothrium latum infection with a brief review of diphyllobothriasis in the Republic of Korea.
    The Korean journal of parasitology, 2007
    Co-Authors: Eun Bin Lee, Eun-hee Shin, Jung-hoon Song, Nam Seon Park, Byung Kook Kang, Hyung Suk Lee, Yoon Ju Han, Hyo Jin Kim, Jong-yil Chai
    Abstract:

    A case of Diphyllobothrium latum infection in a 49-year old man is described, and diphyllobothriasis latum in the Republic of Korea is briefly reviewed. An incomplete strobila of a tapeworm, 95 cm in length, without scolex and neck, was spontaneously discharged in the feces of a patient. On the basis of morphologic characteristics of the worm and eggs, the worm was identified as D. latum. The patient was successfully treated with a single dose (15 mg/kg) of praziquantel. The most probable source of infection was salmon flesh according to the past history of the patient. The first case of D. latum infection was documented in 1971, and this is the 43rd recorded case in the Republic of Korea. The 43 cases were briefly reviewed. The patients' main complaints were gastrointestinal troubles, such as mild abdominal pain, indigestion, and diarrhea, and discharge of tapeworm segments in the feces. The suspected infection sources included raw or improperly cooked flesh of fresh or Brackish Water Fish, including the perch, mullet, salmon, and trout.

  • Identification of Acanthotrema felis (Digenea: Heterophyidae) metacercariae encysted in the Brackish Water Fish Acanthogobius flavimanus
    The Korean journal of parasitology, 2003
    Co-Authors: Eun-taek Han, Min Seo, Jong-yil Chai
    Abstract:

    The metacercariae of Acanthotrema felis Sohn et al., 2003 (Digenea: Heterophyidae) were discovered in a species of the Brackish Water Fish, Acanthogobius flavimanus, in the Republic of Korea. They were experimentally fed to kittens, and adult flukes were harvested 7 days later. The adults were morphologically characterized by the presence of a bipartite seminal vesicle, the ventral sucker associated with a ventrogenital sac enclosing 3 sclerites (2 long and pointed, and 1 short and thumb-like), and an unarmed gonotyl. The adult flukes were identified as A. felis Sohn et al., 2003, and the Brackish Water Fish A. flavimanus has been verified as one of its second intermediate hosts.

Champika Ellawala Kankanamge - One of the best experts on this subject based on the ideXlab platform.

  • Bio-transfer factors and temporal variation of heavy metals in different sexes of three species of edible Brackish Water Fish
    Environmental Science and Pollution Research, 2017
    Co-Authors: Ranil Kavindra Asela Kularatne, Jalaldeen Mohamed Harris, Periyathamby Vinobaba, Champika Ellawala Kankanamge
    Abstract:

    This article discusses bioaccumulation and temporal variation of heavy metals in three edible lagoon Fish species with references to gender. Cd and As were undetected in the three Fish species (i.e., below the method detection limits of 1 μg Cd/kg wet weight and 2 μg As/kg wet weight) irrespective of the periods, and Cd was undetected in the Water too (i.e., below the detection limit of 0.0003 mg/L). Except for Zn (which was mainly available as Zn^2+ in the Water), Pb was present largely as low labile metal-chloride complexes and As as HAsO_4 ^2− as per Visual MINTEQ, version 3.1. Bio-transfer factors of Sn (which was also undetected in the Water; below the detection limit of 0.05 mg/L), Hg, Pb, and Zn were

  • bio transfer factors and temporal variation of heavy metals in different sexes of three species of edible Brackish Water Fish
    Environmental Science and Pollution Research, 2017
    Co-Authors: Ranil Kavindra Asela Kularatne, Jalaldeen Mohamed Harris, Periyathamby Vinobaba, Champika Ellawala Kankanamge
    Abstract:

    This article discusses bioaccumulation and temporal variation of heavy metals in three edible lagoon Fish species with references to gender. Cd and As were undetected in the three Fish species (i.e., below the method detection limits of 1 μg Cd/kg wet weight and 2 μg As/kg wet weight) irrespective of the periods, and Cd was undetected in the Water too (i.e., below the detection limit of 0.0003 mg/L). Except for Zn (which was mainly available as Zn2+ in the Water), Pb was present largely as low labile metal-chloride complexes and As as HAsO4 2− as per Visual MINTEQ, version 3.1. Bio-transfer factors of Sn (which was also undetected in the Water; below the detection limit of 0.05 mg/L), Hg, Pb, and Zn were <1 in both sexes, justifying that bioaccumulation was largely attributed to food rather than uptake from the Water. Metal accumulation patterns differed drastically between the Fish species. Arius maculatus (a carnivore) exhibited higher Zn, Hg, and Sn accumulations during the drier periods (June–September) compared with Mugil cephalus (a detritivore/herbivore) and Etroplus suratensis (an omnivore). Pb was detected only in A. maculatus (July–August) possibly due to biomagnification. Zn was present in higher levels in all species (irrespective of sex) compared with the other metals, but levels were below admissible limits. However, the relationship between temporal variation of Zn and gender in all species was insignificant. In M. cephalus, the temporal variation of Sn and Hg between the sexes was also insignificant. Female A. maculatus and E. suratensis showed higher Hg concentrations, while males showed higher Sn concentrations. Temporal variation patterns of Pb were unclear.

John G Pope - One of the best experts on this subject based on the ideXlab platform.

  • size growth temperature and the natural mortality of marine Fish
    Fish and Fisheries, 2010
    Co-Authors: Henrik Gislason, Niels Daan, Jake Rice, John G Pope
    Abstract:

    The natural mortality of exploited Fish populations is often assumed to be a species-specific constant independent of body size. This assumption has important implications for size-based Fish population models and for predicting the outcome of size-dependent Fisheries management measures such as mesh-size regulations. To test the assumption, we critically review the empirical estimates of the natural mortality, M (year-1), of marine and Brackish Water Fish stocks and model them as a function of von Bertalanffy growth parameters, L8 (cm) and K (year-1), temperature (Kelvin) and length, L (cm). Using the Arrhenius equation to describe the relationship between M and temperature, we find M to be significantly related to length, L8 and K, but not to temperature (R2 = 0.62, P <0.0001, n = 168). Temperature and K are significantly correlated and when K is removed from the model the temperature term becomes significant, but the resulting model explains less of the total variance (R2 = 0.42, P <0.0001, n = 168). The relationships between M, L, L8, K and temperature are shown to be in general accordance with previous theoretical and empirical investigations. We conclude that natural mortality is significantly related to length and growth characteristics and recommend to use the empirical formula: ln(M) = 0.55 - 1.61ln(L) + 1.44ln(L8) + ln(K), for estimating the natural mortality of marine and Brackish Water Fish.

  • Size, growth, temperature and the natural mortality of marine Fish
    Fish and Fisheries, 2010
    Co-Authors: Henrik Gislason, Niels Daan, Jake Rice, John G Pope
    Abstract:

    The natural mortality of exploited Fish populations is often assumed to be a species-specific constant independent of body size. This assumption has important implications for size-based Fish population models and for predicting the outcome of size-dependent Fisheries management measures such as mesh-size regulations. To test the assumption, we critically review the empirical estimates of the natural mortality, M (year-1), of marine and Brackish Water Fish stocks and model them as a function of von Bertalanffy growth parameters, L8 (cm) and K (year-1), temperature (Kelvin) and length, L (cm). Using the Arrhenius equation to describe the relationship between M and temperature, we find M to be significantly related to length, L8 and K, but not to temperature (R2 = 0.62, P

Ranil Kavindra Asela Kularatne - One of the best experts on this subject based on the ideXlab platform.

  • Bio-transfer factors and temporal variation of heavy metals in different sexes of three species of edible Brackish Water Fish
    Environmental Science and Pollution Research, 2017
    Co-Authors: Ranil Kavindra Asela Kularatne, Jalaldeen Mohamed Harris, Periyathamby Vinobaba, Champika Ellawala Kankanamge
    Abstract:

    This article discusses bioaccumulation and temporal variation of heavy metals in three edible lagoon Fish species with references to gender. Cd and As were undetected in the three Fish species (i.e., below the method detection limits of 1 μg Cd/kg wet weight and 2 μg As/kg wet weight) irrespective of the periods, and Cd was undetected in the Water too (i.e., below the detection limit of 0.0003 mg/L). Except for Zn (which was mainly available as Zn^2+ in the Water), Pb was present largely as low labile metal-chloride complexes and As as HAsO_4 ^2− as per Visual MINTEQ, version 3.1. Bio-transfer factors of Sn (which was also undetected in the Water; below the detection limit of 0.05 mg/L), Hg, Pb, and Zn were

  • bio transfer factors and temporal variation of heavy metals in different sexes of three species of edible Brackish Water Fish
    Environmental Science and Pollution Research, 2017
    Co-Authors: Ranil Kavindra Asela Kularatne, Jalaldeen Mohamed Harris, Periyathamby Vinobaba, Champika Ellawala Kankanamge
    Abstract:

    This article discusses bioaccumulation and temporal variation of heavy metals in three edible lagoon Fish species with references to gender. Cd and As were undetected in the three Fish species (i.e., below the method detection limits of 1 μg Cd/kg wet weight and 2 μg As/kg wet weight) irrespective of the periods, and Cd was undetected in the Water too (i.e., below the detection limit of 0.0003 mg/L). Except for Zn (which was mainly available as Zn2+ in the Water), Pb was present largely as low labile metal-chloride complexes and As as HAsO4 2− as per Visual MINTEQ, version 3.1. Bio-transfer factors of Sn (which was also undetected in the Water; below the detection limit of 0.05 mg/L), Hg, Pb, and Zn were <1 in both sexes, justifying that bioaccumulation was largely attributed to food rather than uptake from the Water. Metal accumulation patterns differed drastically between the Fish species. Arius maculatus (a carnivore) exhibited higher Zn, Hg, and Sn accumulations during the drier periods (June–September) compared with Mugil cephalus (a detritivore/herbivore) and Etroplus suratensis (an omnivore). Pb was detected only in A. maculatus (July–August) possibly due to biomagnification. Zn was present in higher levels in all species (irrespective of sex) compared with the other metals, but levels were below admissible limits. However, the relationship between temporal variation of Zn and gender in all species was insignificant. In M. cephalus, the temporal variation of Sn and Hg between the sexes was also insignificant. Female A. maculatus and E. suratensis showed higher Hg concentrations, while males showed higher Sn concentrations. Temporal variation patterns of Pb were unclear.

Henrik Gislason - One of the best experts on this subject based on the ideXlab platform.

  • size growth temperature and the natural mortality of marine Fish
    Fish and Fisheries, 2010
    Co-Authors: Henrik Gislason, Niels Daan, Jake Rice, John G Pope
    Abstract:

    The natural mortality of exploited Fish populations is often assumed to be a species-specific constant independent of body size. This assumption has important implications for size-based Fish population models and for predicting the outcome of size-dependent Fisheries management measures such as mesh-size regulations. To test the assumption, we critically review the empirical estimates of the natural mortality, M (year-1), of marine and Brackish Water Fish stocks and model them as a function of von Bertalanffy growth parameters, L8 (cm) and K (year-1), temperature (Kelvin) and length, L (cm). Using the Arrhenius equation to describe the relationship between M and temperature, we find M to be significantly related to length, L8 and K, but not to temperature (R2 = 0.62, P <0.0001, n = 168). Temperature and K are significantly correlated and when K is removed from the model the temperature term becomes significant, but the resulting model explains less of the total variance (R2 = 0.42, P <0.0001, n = 168). The relationships between M, L, L8, K and temperature are shown to be in general accordance with previous theoretical and empirical investigations. We conclude that natural mortality is significantly related to length and growth characteristics and recommend to use the empirical formula: ln(M) = 0.55 - 1.61ln(L) + 1.44ln(L8) + ln(K), for estimating the natural mortality of marine and Brackish Water Fish.

  • Size, growth, temperature and the natural mortality of marine Fish
    Fish and Fisheries, 2010
    Co-Authors: Henrik Gislason, Niels Daan, Jake Rice, John G Pope
    Abstract:

    The natural mortality of exploited Fish populations is often assumed to be a species-specific constant independent of body size. This assumption has important implications for size-based Fish population models and for predicting the outcome of size-dependent Fisheries management measures such as mesh-size regulations. To test the assumption, we critically review the empirical estimates of the natural mortality, M (year-1), of marine and Brackish Water Fish stocks and model them as a function of von Bertalanffy growth parameters, L8 (cm) and K (year-1), temperature (Kelvin) and length, L (cm). Using the Arrhenius equation to describe the relationship between M and temperature, we find M to be significantly related to length, L8 and K, but not to temperature (R2 = 0.62, P