Life cycle studies on two Digenea, Paradistomum geckonum (Dicrocoeliidae) and Mesocoelium sociale (Mesocoeliidae), in geckonid lizards from Indonesia

1987 ◽  
Vol 65 (10) ◽  
pp. 2491-2497 ◽  
Author(s):  
Murray J. Kennedy ◽  
L. M. Killick ◽  
M. Beverley-Burton

Life cycle studies of Paradistomum geckonum (Dicrocoeliidae) were attempted experimentally. The pulmonate gastropod Lamellaxis gracilis served as the first intermediate host; geckonid lizards (Cosymbotus platyurus, Gehyra mutilata, and Hemidactylus frenatus) served as definitive hosts. The life cycle of Mesocoelium sociale (Mesocoeliidae) was studied in naturally infected first intermediate hosts (L. gracilis, Huttonella bicolor) and experimentally in geckonid definitive hosts (C. platyurus, G. mutilata, and H. frenatus). Some naturally infected L. gracilis were infected concurrently with larval stages of both digeneans. Second intermediate hosts, presumed to be arthropods, were experimentally unnecessary. Metacercariae of P. geckonum were not found. Cercariae of M. sociale formed encysted metacercariae in the same individual snails.

1986 ◽  
Vol 34 (2) ◽  
pp. 279 ◽  
Author(s):  
TH Cribb

Stemmatostoma pearsoni, gen. et sp. nov., is described from the intestine of Leiopotherapon unicolor (Gunther) and Macquaria novemaculeata (Steindachner) in Queensland. Stemmatostoma is placed within the Neochasminae and is distinguished by its long oesophagus, compact ovary, short caeca, pre-ovarian vitellaria, simple gonotyl and funnel-shaped oral sucker. The diagnosis of the Neochasminae is emended excluding Parspina Pearse. Telogaster opisthorchis Macfarlane is recorded from the intestine of Anguilla reinhardtii Steindachner from Victoria. The spinose oral suckers of S. pearsoni and T. opisthorchis are capable of being retracted into tegumental pockets. It is postulated that this arrangement may be widespread amongst spinose cryptogonimids. The first intermediate host of S. pearsoni is Posticobia brazieri (Smith), a prosobranch snail. The second intermediate hosts are freshwater fish: Hypseleotris galii (Ogilby), H. compressus (Krefft), Mogurnda mogurnda (Richardson), M. adspersa (Castelnau), Philypnodon grandiceps (Krefft), Gobiomorphus australis (Krefft), and Pseudomugil signifer Kner. Within the snail there is a mother sporocyst generation, a redial generation and a cercarial generation. Development of the mother sporocyst is similar to that described for other opisthorchioids. Cryptogonimid cercariae are characterized by 16 flame-cells, pre-vesicular penetration glands, dorso-ventral caudal finfolds and absence of body pigmentation. On the basis of cercarial and adult morphology it is proposed that Pseudexorchis Yamaguti be excluded from the Cryptogonimidae.


1944 ◽  
Vol 22d (1) ◽  
pp. 6-16 ◽  
Author(s):  
Thomas W. M. Cameron

A trematode, widely distributed in Canada, and occurring in man and other fish-eating mammals, is described and its taxonomy discussed. Its life cycle has been worked out and it is shown to involve a snail, Amnicola limosa porata as first intermediate host and a fish, the common sucker (Catostomus commersonii) as the second intermediate host. The larval stages are described.


2000 ◽  
Vol 74 (2) ◽  
pp. 165-172 ◽  
Author(s):  
C. Muñoz-Antolí ◽  
R. Toledo ◽  
J.G. Esteban

AbstractThe morphology of the different larval stages and life cycle ofHypoderaeum conoideum(Trematoda: Echinostomatidae) are described. The freshwater snail speciesLymnaea peregra(Gastropoda: Lymnaeidae) serves as the natural first intermediate host and this andL. corvusserve as experimental first intermediate hosts. These and other freshwater snails, such asPhysella acutaandGyraulus chinensis, in turn serve as second intermediate hosts. Adult worms were obtained from chicks and ducks, but not from rats, mice and golden hamsters. The morphology of the larval stages is compared with previous work onH. conoideum. Several aspects of the biology of the life history stages are described with emphasis on the transmission dynamics of the free-living stages. Differential suitability of the snail species that may act as first and/or second intermediate hosts is studied and discussed.


1953 ◽  
Vol 1 (2) ◽  
pp. 193 ◽  
Author(s):  
PH Durie

A description of the development at 27�C. of Ceylonocotyle streptocoelium (Fischoeder 1901) Nasmark 1937, a paramphistome from the rumen and reticulum of sheep and cattle in Australia, is given in detail. Eggs hatched after 16 days' incubation and miracidia penetrated the intermediate host, a planorbid snail, Glyptanisus gilberti Dunker 1848, through the mantle cavity. The development of the larval stages of the parasite within the intermediate host was completed 34 days after infection, when cerariae were secreted by snails. Cysts of C. streptocoelium fed to sheep and cattle showed that flukes reached maturity in the rumen in 48 and 56 days respectively. The life cycle of the fluke, therefore, was completed in a minimum period of approximately 3.5 months under these conditions. It was found that temperature had a marked effect on the rate of development of larval stages within the molluscan intermediate host, the developmental period at 20�C. being twice as long as that at 27�C. The various stages occurring in the molluscan intermediate host are described in detail. The development of Paramphistomum ichikauiai Fukui 1922 is compared with that of C. streptocoelium. The rate of development was found to be more rapid than for C. streptocoelium under the same conditions. Eggs hatched after 12 days incubation and cercariae were secreted from the intermediate host, Segnitilia alphena Iredale 1943, 25 days after infection. Flukes were found to reach maturity in sheep 49-51 days after cysts had been fed. The eggs and intra-molluscan stages are similar in both species, but the cercariae may be readily distinguished by anatomical differences in their excretory systems. The life cycle in this species takes approximately 3 months to complete under these conditions. The molluscan intermediate hosts of the two species of amphistomes are described and notes on their bionomics are given.


1985 ◽  
Vol 33 (5) ◽  
pp. 715 ◽  
Author(s):  
TH Cribb

Opecoelus variabilis, sp. nov., is described from the intestine of 17 species of Australian freshwater fish. The highly variable anatomy of this species highlights the closeness of Opecoelus and Opegaster. Opegaster is made a synonym of Opecoelus and a new diagnosis is proposed for Opecoelus. The first intermediate host of O. variabilis is the prosobranch snail Posticobia brazieri, and the second intermediate hosts are five species of atyid, palaemonid and parastacid Crustacea. Features of the life cycle are the production of daughter sporocysts by the mother sporocyst when only one-quarter of its full size, and the further development of the metacercaria in the second intermediate host after becoming infective to the definitive host.


Parasitology ◽  
2017 ◽  
Vol 145 (3) ◽  
pp. 307-312 ◽  
Author(s):  
EGIE E. ENABULELE ◽  
SCOTT P. LAWTON ◽  
ANTHONY J. WALKER ◽  
RUTH S. KIRK

SUMMARYLecithodendrium linstowi is one of the most prevalent and abundant trematodes of bats, but the larval stages and intermediate hosts have not been identified. We present the first molecular and morphological characterization of the cercariae of L. linstowi based on a phylogenetic analysis of partial fragments of LSU and ITS2 rDNA. The first intermediate host was incriminated as Radix balthica by DNA barcoding using cox1 and ITS2 sequences, although the snail morphologically resembled Radix peregra, emphasizing the requirement for molecular identification of lymnaeids as important intermediate hosts of medical and veterinary impact. The application of molecular data in this study has enabled linkage of life cycle stages and accurate incrimination of the first intermediate host.


Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 34
Author(s):  
Kristina M. Hill-Spanik ◽  
Claudia Sams ◽  
Vincent A. Connors ◽  
Tessa Bricker ◽  
Isaure de Buron

The coquina, Donax variabilis, is a known intermediate host of monorchiid and gymnophallid digeneans. Limited morphological criteria for the host and the digeneans’ larval stages have caused confusion in records. Herein, identities of coquinas from the United States (US) Atlantic coast were verified molecularly. We demonstrate that the current GenBank sequences for D. variabilis are erroneous, with the US sequence referring to D. fossor. Two cercariae and three metacercariae previously described in the Gulf of Mexico and one new cercaria were identified morphologically and molecularly, with only metacercariae occurring in both hosts. On the Southeast Atlantic coast, D. variabilis’ role is limited to being a facultative second intermediate host, and D. fossor, an older species, acts as both first and second intermediate hosts. Sequencing demonstrated 100% similarities between larval stages for each of the three digeneans. Sporocysts, single tail cercariae, and metacercariae in the incurrent siphon had sequences identical to those of monorchiid Lasiotocus trachinoti, for which we provide the complete life cycle. Adults are not known for the other two digeneans, and sequences from their larval stages were not identical to any in GenBank. Large sporocysts, cercariae (Cercaria choanura), and metacercariae in the coquinas’ foot were identified as Lasiotocus choanura (Hopkins, 1958) n. comb. Small sporocysts, furcocercous cercariae, and metacercariae in the mantle were identified as gymnophallid Parvatrema cf. donacis. We clarify records wherein authors recognized the three digenean species but confused their life stages, and probably the hosts, as D. variabilis is sympatric with cryptic D. texasianus in the Gulf of Mexico.


Parasitology ◽  
1982 ◽  
Vol 84 (1) ◽  
pp. 131-135 ◽  
Author(s):  
R. Vanoverschelde

SUMMARYThe influence of temperature and salinity on miracidial longevity and miracidial infectivity of the digenean,Himasthla militaris, has been examined. At 14, 25 and 30 °C the half-life of the miracidia was 1200, 630 and 420 min respectively, and infection of the first intermediate host,Hydrobia ventrosa, only occurred at 25 and 30 °C, for both temperatures 52% became infected. In the range 2·1 to 34‰ (2·1, 4·2, 8·5, 17 and 34‰) the miracidia had a minimal and maximal half-life of 60 and 630 min in water with a salinity of 2·1 and 17‰ respectively, while the infection of the snail host was possible only in water with a salinity of 8·5 and 17‰.


1989 ◽  
Vol 63 (1) ◽  
pp. 39-45 ◽  
Author(s):  
M. Irshadullah ◽  
W. A. Nizami ◽  
C. N. L. Macpherson

ABSTRACTThe present study investigated the suitability and importance of buffaloes, camels, sheep, goats and pigs in maintaining the life-cycle of Echinococcus granulosus in Aligarh, India. A total of 565 (36%) of 1556 buffaloes, 20 (2%) of 1208 goats, 5 (1%) of 559 pigs, 6 (6%) of 109 sheep and two of three camels were found to harbour hydatid cysts. The frequency distribution of the hydatid cysts in each intermediate host species was over-dispersed and in buffaloes cyst fertility increased with increasing cyst size. Of 2171, 95 and four buffalo, goat, and camel cysts examined 327 (15%), two (2%) and three cysts respectively were fertile. No pig or sheep cysts were found to contain protoscoleces. The unfenced buffalo abattoir and the large number of dogs allowed access to the abattoir coupled to the number of buffaloes slaughtered in comparison to the other potential hosts, indicates that the buffalo is the most significant host for maintaining the life-cycle of the parasite in this area of India. Applicable control measures for the region are suggested.


Parasitology ◽  
1964 ◽  
Vol 54 (1) ◽  
pp. 1-41 ◽  
Author(s):  
B. L. James

1. Parvatrema homoeotecnum sp.nov. from the oystercatcher, Haematopus ostralegus occidentalis Neumann at Aberystwyth is described and compared with other species of the genus.2. The life cycle of this species is unique. The larval stages occur in the gastropod, Littorina saxatilis (Olivi) subsp. tenebrosa (Montagu) and include germinal sacs which have a structure and development similar to an adult digenean. There are no free-living stages and only one intermediate host.3. The significance of this unique life cycle is discussed.4. The family Gymnophallidae Morozov, 1955, is reviewed. Emended definitions are given for the family, subfamilies and genera. Keys, diagnostic features and brief notes of the species are included.I am very grateful to Dr Gwendolen Rees, who suggested the investigation which led to the discovery of this species, for her advice and indispensable assistance throughout the work and the preparation of this paper. I am also grateful to the late Professor T. A. Stephenson for his interest and for the provision of working facilities; to Mr W. A. Ballantine, Mr A. H. Clarke, Jr., Mr C. Curtis, Miss G. P. F. Evans, Dr V. Fretter, Professor L. A. Harvey, Mr D. H. Jones and Dr J. Lewis who sent me specimens of Littorina saxatilis; to Professor R. M. Cable and Emerit. Professor G. R. La Rue for helpful suggestions; to Mr J. R. Hirst and Mr D. Hemingway Jones for photographic and technical assistance and to the Department of Scientific and Industrial Research for a grant which made the work possible.


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