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

Abstract

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.