scholarly journals Observations on the life history of Fasciola gigantica, the common liver fluke of cattle in Hawaii, and the intermediate host, Fossaria ollula /

Author(s):  
Joseph E. Alicata
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.


Parasitology ◽  
1918 ◽  
Vol 10 (3) ◽  
pp. 311-319 ◽  
Author(s):  
J. D. F. Gilchrist

Some years ago, in endeavouring to obtain various stages in the life history of the liver-fluke in South Africa for teaching purposes, I found that, although the parasite is fairly common on some farms in this country, the intermediate host had not yet been definitely ascertained. In Europe, as is well known, the intermediate host is the fresh-water snail Limnaea truncatula, but this species has not been recorded with certainty from South Africa. The commonest fresh-water snail here is Physa (Isidora) tropica and a preliminary examination of a few specimens of this mollusc from Muizenberg Lake revealed abundant stages of fluke very closely resembling those of the liver-fluke. Additional specimens procured from the neighbourhood also afforded abundant material of the same stages. The only difficulty in accepting this as a solution of the problem was that, though placed in the most favourable conditions, the free swimming form (cercaria) was never observed to encyst.


Parasitology ◽  
1932 ◽  
Vol 24 (2) ◽  
pp. 210-224 ◽  
Author(s):  
Cecil A. Hoare

This paper contains a report on a collection of parasitic protozoa from the blood of some vertebrate animals of Uganda.Seven new species and a number of parasites recorded for new hosts are described. New observations on some known parasites are also recorded.An account is given of the life history of the crocodile haemogregarine. It is shown that the schizogony of Hepatozoon pettiti (nomen novum for Haemogregarina pettiti) occurs in the liver of the crocodile, while the sporogony takes place in Glossina palpalis, its intermediate host.A list of all the blood parasites found, together with their hosts, is given.


1973 ◽  
Vol 71 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
Sylvio Celso Goncalves da Costa ◽  
Samuel B. Pessoa ◽  
Neize de Moura Pereira ◽  
Tania Colombo

The main object of the present paper is to furnish a brief account to the knowledgement of Protozoa parasitic in common Brazilian frog of the genus Leptodactylus for general students in Zoology and for investigators that use this frog as a laboratory animal. Hepatozoon leptodactyli (Haemogregarina leptodactyli) was found in two species of frogs - Leptodactylus ocellatus and L. pentadactylus - in which develop schizogony whereas sporogony occurs in the leech Haementeria lutzi as was obtainded in experimental conditions. Intracellular forms have been found in peripheral circulation, chiefly in erythrocytes, but we have found them in leukocytes too. Tissue stages were found in frog, liver, lungs, spleen, gut, brain and heart. The occurence of hemogregarine in the Central Nervous System was recorded by Costa & al,(13) and Ball (2). Some cytochemical methods were employed in attempt to differentiate gametocytes from trophozoites in the peripheral blood and to characterize the cystic membrane as well. The speorogonic cycle was developed in only one specie of leech. A brief description of the parasite is given.


2001 ◽  
Vol 20 (2) ◽  
pp. 56-71
Author(s):  
Editorial Office

This paper focuses on the geographical distribution and the habitats of Lymnaea natalensis, the snail intermediate host of the liver fluke, Fasciola gigantica, as reflected by the collection sites of its 4 552 samples currently on record in the National Freshwater Snail Collection (NFSC) of South Africa. Although this species was represented in a variety of waterbodies, the majority of samples(±70%)came from rivers, brooks and dams and in 70.8% of the cases the water was described as permanent and in 71.8% as slow flowing or standing. The results of life-table studies conducted by various authors indicated that temperature should be a relatively unimportant factor in determining its geographical distribution, but that the availability of permanent water should be decisive for its presence in a given habitat. These results are in agreement with the finding that only 7.5% of the samples of this species in the NFSC were collected in habitats which were described as seasonal. Furthermore, it gives a logical explanation for the sporadic occurrence, or total absence of this species in the more arid regions of South Africa. Water impoundments and irrigation networks contribute to a large extent towards creating perennial habitats which would be suitable for L. natalensis. As intermediate host for one of the liver fluke species which already is an economic factor in South Africa, this certainly is an aspect which ought to be reckoned within the planning and construction of new irrigation schemes.


Parasitology ◽  
1953 ◽  
Vol 42 (3-4) ◽  
pp. 244-258 ◽  
Author(s):  
J. F. A. Sprent

The development of Ascaris devosi, a parasite of the fisher and marten, was followed from the egg to the adult stage using the white mouse and the ferret as the intermediate and final hosts respectively. The eggs contained motile 1st stage larvae 6 days after cleavage and were infective at 12 days, the 1st moult having already occurred. The eggs remained infective for at least 1 year. The 2nd stage larva after hatching from the egg in the intestine of the mouse passes through the intestinal wall to the liver and mesenteric tissues. At 3 days after infection they were recovered from the heart, lungs, brain, kidneys and from the carcass. The larvae grow and store food material during the 2nd stage and between 8 and 12 days after infection they undergo the 2nd moult. The mouse shows the most severe pulmonary symptoms on the 3rd and 4th days after infection, the lungs showing complete red hepatization at this time. The 3rd stage larva is relatively inactive and becomes encapsulated in various tissues, particularly in the muscular and subcutaneous tissues of the neck, shoulders and thorax. The chief developmental changes, apart from growth, which occur in the 2nd and 3rd stage larvae are: (i) the intestine develops from a single row of cells to a multi-cellular tube; (ii) the body cavity appears; (iii) the excretory lobes appear, the nucleus on the left side becoming prominent at the end of the 2nd stage; (iv) the cuticle shows transverse striations at the end of the 2nd stage; (v) the lateral lines become prominent.The encapsulated 3rd stage larvae remained alive for at least six months in the tissues of mice and at 25 days after infection of the mouse they were able to develop in the young ferret following killing and ingestion of the mouse. No infection of ferrets was obtained through oral administration of embryonated eggs or 3rd stage larvae digested from mouse tissues.The 3rd moult occurred in the intestine of the young ferret 3–4 days after infection; in adult ferrets the 3rd stage larvae were evidently unable to gain a hold and were passed out in the faeces. In the next 2–3 weeks the larva grew from about 2 to 16 mm. the 4th moult occurring between 2 and 3 weeks after infection. During the 4th stage the lips develop into the adult form and sexual differentiation occurs. In the female the genital rudiment moves forward and becomes differentiated into the vagina, uteri and ovaries. The vulva remains closed throughout the 4th stage.The adult parasites had developed to sexual maturity by 56 days after infection, but they continued to grow and were considerably longer at 6 months after infection. The position of the vulva relative to the body length was found to move from about midway along the body in the 4th stage larva to a position at the junction of the anterior and middle third of the body in the mature adult.The life history of this parasite is discussed in relation to that of A. lumbricoides and other species. It is considered that the life history of A. devosi, requiring as it does a true intermediate host for its completion, provides further information on the evolutionary development of the ascaris group. This work accordingly supports the hypothesis that the earliest members of this group utilized an intermediate host and does not support that which supposes that ascaris parasites are descended from skin-penetrating forms.During this investigation the writer has benefited considerably from correspondence with Dr J. D. Tiner, Department of Zoology, University of Illinois, Urbana, Illinois, U.S.A. His thanks are also due to Dr H. B. Speakman and Dr A. M. Fallis for their encouragement, guidance and help.This work was supported by the Province of Ontario on the recommendation of the Research Council of Ontario.Grateful acknowledgement is made to Mr Cliff Smith of the Connaught Medical Research Laboratories of the University of Toronto for photographic work.


1878 ◽  
Vol 27 (185-189) ◽  
pp. 481-485

Notwithstanding the numerous and fruitful researches which have been recently made into the life-history of Bacteria, our knowledge of the common and interesting curved and spiral forms— the Vibrio and Spirillum of Ehrenberg—has made little or no advance since his time, neither embryonic nor reproductive forms having ever been observed; while even the zooglœa phase, so characteristic of Bacterium and Bacillus, has only once been mentioned, and then in a different form. A fresh-water aquarium, which has been stagnating since last summer in the Physiological Laboratory of University College, con­tained in winter vast numbers of ordinary motile Spirillum. On recently re-examining the water, one zooglœa film after another having in the meantime formed on the surface, thickened, broken, and sunk, we found that these motile forms had almost disappeared, while the films consisted almost entirely of resting Spirillum in a gelatinous-looking matrix, similar to that of Bacterium and Bacillus . Among these were two or three apparently distinct kinds of filaments, some resting and colourless, others motile, and filled with highly refracting bright yellowish-brown spheres. Such a field is represented in fig. 1.


Author(s):  
Marie V. Lebour ◽  
Richard Elmhirst

Parorchis acanthus is a Trematode described by Nicoll (1907) from the bursa Fabricii and rectum of the Herring Gull, Larus argentatus; in 1906 he first described it as Zeugorchis acanthus. Originally found at St. Andrews, it is now known to be common at Millport and also occurs in gulls from the Northumberland coast, and probably is abundant elsewhere. Nicoll found it once in the Common Gull, Larus canus. In 1907 (Lebour, 1907) one of the present writers described a cercaria occurring in rediæ from Purpura lapillus. This was named Cercaria purpurœ sp. inq., and afterwards identified with young stages of Parorchis acanthus in the Herring Gull (Lebour, 1914). It was thus shown that the first host of this Trematode is Purpura lapillus and the final host the Herring Gull, but the intermediate host was unknown. Localities for the cercaria were Loch Ryan, Wigtownshire; Budle Bay, Fenham Flats and Cullercoats in Northumberland; Robin Hood's Bay in Yorkshire; and Millport. Adults occur at St. Andrews, Northumberland coast and Millport, as already stated.The Cercaria appeared to be closely related to Echinostomum cercariæ, and it was suggested (Lebour, 1914) that the intermediate host would probably be some marine bivalve, as it is often so with Echinostomum (e.g. E. secundum in Mytilus edulis and Cardium edule, E. leptosomum in Scrobicularia tenuis). This suggestion now proves to be correct, and we are able to show that the intermediate host of Parorchis acanthus is Mytilus edulis or Cardium edule.On August 13th, 1921, at the Millport Station some larval cercariæ were noticed by Elmhirst swimming in a small glass aquarium, which contained a collection of Purpura lapillus, Cardium edule and Mytilus edulis.


Sign in / Sign up

Export Citation Format

Share Document