The prevalence of Paradistomum geckonum, Mesocoelium sociale, and Postorchigenes ovatus (Digenea) in lizards (Sauria) from Indonesia

Three species of Digenea were found in collections of seven species of lizards from Indonesia from May 1978 to February 1979: Paradistomum geckonum Bhalerao, 1929 (Dicrocoeliidae) was found in the gallbladder and bile duct of Hemidactylus frenatus, Cosymbotus platyurus, Gehyra mutilata, Gekko gecko, Calotes versicolor, and Takydromus sexlineatus; Mesocoelium sociale Lühe, 1901 (Mesocoeliidae) in the small intestine and stomach of H. frenatus, C. platyurus, G. gecko, C. versicolor, and Mabuya multifasciata; and Postorchigenes ovatus Tubangui, 1928 (Lecithodendriidae) in the small intestine of H. frenatus, C. platyurus, G. mutilata, and G. gecko. Data on prevalence, intensity, and location within the host are given for each digenean species. No variations were observed between wet and dry seasons. Prevalence and intensity of P. geckonum and P. ovatus were similar in males and females of each host species examined except for the gecko Gehyra mutilata, in which females had a significantly higher prevalence of infection of both parasites than males. This difference is possibly due to differential food preference.

A scanning electron microscopic study of the alimentary canal in the grass lizard

The histology of the reptilian alimentary tract has been described in numerous light microscopic studies. However, no information on surface morphology is available for any species of reptiles. In the present communication, the alimentary canal of the grass lizard, Takydromus sexlineatus, is investigated by means of light and scanning electron microscopy.Various portions of the alimentary canal were dissected and removed rapidly. While immersed in cacodylate buffer, the inner lining of each portion was exposed and rinsed. The tissues were then fixed in 2% glutaraldehyde in cacodylate buffer, dehydrated in graded ethanol series, and critical point dried with carbon dioxide. After coating with gold, the specimens were examined on a JOEL JSM-35 operated at 35 KV. Tissues for light microscopy were processed routinely.

Observations on digeneans from lizards (Sauria) in Indonesia (Paradistomum geckonum, Mesocoelium sociale, and Postorchigenes ovatus) with a revision of Paradistomum Kossack, 1910 (Dicrocoeliidae)

An emended diagnosis for Paradistomum (syn. Paradistomoides) (Dicrocoeliidae) is given and Paradistomum geckonum is redescribed. Paradistomum geckonum occurred in the gallbladder or bile duct of Hemidactylus frenatus, Cosymbotus platyurus, Gehyra mutilata, Gekko gecko, Calotes versicolor, and Takydromus sexlineatus. Taxonomic characters used to separate P. geckonum from other Paradistomum spp. are evaluated and the effects of two different fixation techniques compared. Of the species occurring in Southeast Asian lizards, P. gregarinum, P. oroterminosus, P. paloensis, P. medius, P. brevis, and P. laruei are made synonyms of P. geckonum; P. mutabile, P. indica, P. samoensis, P. orientalis, P. spatulatus (n. comb.), and P. mujibi (n. comb.) are considered valid species and the taxonomic status of P. ceratophorae, P. excalotes, P. intestinalis (n. comb.), P. lanceolatus (n. comb.), P. diminutus (n. comb.), P. intermedius (n. comb.), P. elongatus (n. comb.), and P. hemidactylus (n. comb.) should be clarified as new material becomes available. Postorchigenes ovatus (Lecithodendriidae) occurred in the small intestine of the first four hosts listed above; Mesocoelium sociale (Brachycoeliidae) occurred in the small intestine or stomach of all hosts listed above except G. mutilata and T. sexlineatus, and was the only digenean found in Mabuya multifasciata. No digeneans were found in H. bowringi, H. garnoti, Draco volans, or Lygosoma spp. Gekko gecko was a new host record for all three parasites and C. platyurus for M. sociale and P. ovatus. Other new host records were C. versicolor and T. sexlineatus for P. gregarinum, H. frenatus for M. sociale, and G. mutilata for P. ovatus. All infections constitute new geographic records. Morphometric data are presented in tabular form for all three species.