THE MORPHOLOGY, TAXONOMY, AND LIFE HISTORY OF METORCHIS CONJUNCTUS (COBBOLD, 1860)

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.

1978 ◽  
Vol 52 (3) ◽  
pp. 251-259 ◽  
Author(s):  
R. Madhavi

ABSTRACTThe life cycle of Genarchopsis goppo a hemiurid trematode found in the stomach of Channa punctata has been worked out in detail. The egg contains a fully developed miracidium at the time of liberation. The miracidium contains a ciliated covering, a long apical gland and a crown of spines at the anterior end. The snail Amnicola travancorica acts as the first intermediate host inside which the miracidium passes through sporocyst and redial generations. The cercaria is of cystophorous type and is identical to Cercariae Indicae Sewell XXXV. Metacercaria occurs in the ostracods Stenocypris malcolmsoni and Eucyoris capensis. The fish Aplocheilus panchax serves as the paratenic host. The entire developmental cycle from egg to egg producing adult takes 3 months.


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.


Parasitology ◽  
1952 ◽  
Vol 42 (1-2) ◽  
pp. 92-113 ◽  
Author(s):  
Gwendolen Rees

1. Large numbers of Plagiorchis (M.) megalorchis n.nom. were found in the intestine of four turkey poults of a total of thirteen which had died on a farm in Radnorshire. Presumably the presence of the parasites was the cause of death.2. The anatomy of the adult worm is described.3. The first intermediate host of the parasite is Lymnaea pereger, and the second intermediate host any of the following species of insect larvae: Chironomus riparius Meigen, Culicoides stigma Meigen, Culicoides nubeculosus Meigen and Anatopynia (Psectrotanypus) varius Fabr.4. The larval stages of the worm are described.5. The life cycle has been demonstrated experimentally by the feeding of insect larvae containing encysted cercariae to turkey poults.6. The turkey is probably not the normal host of Plagiorchis (M.) megalorchis. It is most likely that it occurs naturally in some species of wild bird, but this is not yet known.


Parasitology ◽  
1935 ◽  
Vol 27 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Wendell H. Krull

The life history of Panopistus pricei, as determined experimentally, has been described, together with the life history stages, including the sporocyst, cercaria and metacercaria. The snail Zonitoides arboreus has been determined experimentally to be a first and second intermediate host of the parasite.


Parasitology ◽  
1969 ◽  
Vol 59 (3) ◽  
pp. 663-682 ◽  
Author(s):  
F. R. Allison

1. Three new species of eugregarine are described from the mid-gut of the larva of Costelytra zealandica (White).2. Euspora zealandica occurs in the anterior region of the mid-gut near the gut caeca. Slictospora costelytrae occurs just posteriorly to E. zealandica. Euspora sp. occurs posteriorly to the malpighian tubules, but was found only rarely.3. A description of the species and the life-cycle of two species are given.4. The life-cycle of S. costelytrae takes about 8 weeks and that of E. zealandica 6 weeks.5. Gametocysts will develop only at a humidity of 95–100 %.6. The bi-associative species, E. zealandica, is more abundant in the 1st and 2nd instars than the large species, S. costelytrae. Both species are equally abundant in the 3rd instars, but the peak for incidence was in May for E. zealandica and June for S. costelytrae. This is related to the longer period of time taken for the life-history of S. costelytrae.7. The incidence of gregarines builds up in each instar to over 90% then falls off, the time of fall off corresponding with the production of gametocysts which pass out with the faeces of the grub.8. The gregarines mostly complete their cycle before the instars moult. This is borne out by the observation that cysts were not found in the smallest size group of each instar. There were many cases in the larger size group of all three instars where cysts only occurred.9. Gametocysts are produced mainly in the autumn.10. Gregarines were not found in grubs approaching metamorphosis (prepupae) nor in pupae nor adults.11. It seems unlikely from the results that the gregarines have an adverse effect on the grubs as, in general, it was found that the larger grubs had the greater number of gregarines present, but further work on this is needed.12. The life-history of the gregarines is closely correlated with the life-history of the beetle.13. The presence of the gregarines only in the larval stages is related to the different habitat and behaviour of larva and adult.I am grateful to the University Grants Committee for financial support.


Parasitology ◽  
1960 ◽  
Vol 50 (3-4) ◽  
pp. 551-575 ◽  
Author(s):  
P. Nasir

1. The life cycle of Cotylurus brevis Dubois and Rausch, from the cercaria to the adult, has been investigated for the first time by using laboratory-bred primary, secondary and definitive hosts. The holometabolic metamorphosis with the formation of a tetracotyle stage in a second intermediate host has been described in detail.2. The cercaria of C. brevis obtained from Lymnaea stagnalis in Edgbaston Pool has been found to be identical with Cercaria helvetica XXXIV Dubois from Lake Neuchâtel. The total number of flame cells in the cercaria is twenty, as opposed to the fourteen in the cercaria of Cotylurus cornutus Rudolphi (= ‘Strigea tarda’ described by Mathias (1925), Harper (1929, 1931) and Wesenberg-Lund (1934)).3. In nature the second intermediate host of Cotylurus brevis is Lymnaea stagnalis. Under experimental conditions L. pereger and L. auricularia were also found to act as second intermediate hosts, but neither Planorbis corneus, P. carinatus nor various leeches could act as second intermediate hosts.4. The tetracotyle stage of Cotylurus brevis is morphologically indistinguishable from the corresponding stage of other species of Cotylurus.


2015 ◽  
Vol 60 (4) ◽  
Author(s):  
Pilar Alda ◽  
Nicolás Bonel ◽  
Carlos J. Panei ◽  
Néstor J. Cazzaniga ◽  
Sergio R. Martorelli

AbstractThis is the first study that used species-specific DNA primers to confirm the presence of the heterophyid Ascocotyle (Phagicola) longa Ransom, 1920 in its first intermediate host. The larval stages (rediae and cercariae) of this parasite were morphologically and genetically identified in the gonad of the intertidal mud snail Heleobia australis (d’Orbigny, 1835) (Cochliopidae) in the Bahía Blanca estuary, Argentina. In addition, we asked whether the prevalence in H. australis varied between seasons. Mullets - the second intermediate host of this heterophyid - migrate in estuaries during the warmer seasons and it is expected that piscivorous birds and mammals - the definitive hosts - prey more intensively on this species at those times. Thus, the number of parasite eggs released into the tidal flat within their feces should be higher, thereby increasing the ingestion of the parasite by H. australis.We therefore expected a higher prevalence of A. (P.) longa in H. australis in the Bahía Blanca estuary during spring and summer than autumn and winter. We found that 16 out of 2,744 specimens of H. australis had been infected with A. (P.) longa (total prevalence of 0.58%). Nonetheless, the prevalence showed no significant variation between seasons. Hence, we discuss an alternative scenario where the lack of seasonal changes might be mostly related to the permanent residence of definitive hosts in the estuary and not to the seasonal recruitment of mullets. Finally, we highlight the need for more experimental and comparative approaches in order to understand the diagnosis and geographical distribution of this worldwide heterophyid.


1972 ◽  
Vol 46 (1) ◽  
pp. 35-46 ◽  
Author(s):  
S. C. Dutt ◽  
H. D. Srivastava

The life cycle of Gastrodiscoidcs hominis has been described using Helicorbis coenosus as the experimental intermediate host and the pig as the definitive host.The morphology of the miracidium, redia and metacercaria has been described. Data have been furnished on the infection and longevity, of and production of cercariae by the snail host, and the growth and development of the adult-fluke in the definitive host.


1927 ◽  
Vol 5 (2) ◽  
pp. 67-80 ◽  
Author(s):  
Thomas W. M. Cameron

Until recently, it had generally been accepted that the life history of Ollulanus tricuspis was a complicated one involving an intermediate host, the mouse. Last year, however, I drew attention to the fact that the larval stages, both in the cat and in the mouse, believed by Leuckart to belong to Ollulanus, were really those of Ælurostrongylus, the lungworm of the cat. Subsequent work has enabled some of the details of the life history of Ollulanus to be elucidated—although by no means all—and these are considered in this paper.


1978 ◽  
Vol 52 (1) ◽  
pp. 51-59 ◽  
Author(s):  
R. Madhavi

ABSTRACTThe life history of Allocreadium fasciatusi which occurs in the intestine of a freshwater fish Aplocheilus melastigma has been worked out in detail. The snail Amnicola travancorica acts as the first intermediate host. The miracidium hatching out from the eggs attacks the snail and passes through two generations of rediae. Cercariae are of ophthalmoxiphidiocercous type with very long tail and are identical to Cercariae Indicae XLIX Sewell, 1922. The cercariae penetrate and develop into metacercariae in the haemecoel of the copepods Mesocyclops leuckarti, Microcyclops varicans and Marcocyclops distructus. Upon ingestion by the definitive host, the metacercariae excyst and develop into adults. All the stages in the life cycle are described and the life cycle is compared with other allocreadiid life cycles. The original description of A. fasciatusi is revised and Psilostomum chilkai Chatterji, 1956 from Lates calcalifer is synonymized with it.


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