On the life history of Ascaris devosi and its development in the white mouse and the domestic ferret

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.

Parasitology ◽  
1922 ◽  
Vol 14 (3-4) ◽  
pp. 268-281 ◽  
Author(s):  
F. W. Flattely

Lambs contract Moniezia infection either at or very soon after birth, since they have been observed to harbour adult worms at 2–3 months old and in one case, to pass proglottids at 4–6 weeks.The intermediate host, if such exists, must be frequent on the pasture in early spring, otherwise lambs would not be found to harbour adult tapeworms so regularly or in such numbers when slaughtered in early summer. In the small intestine of a lamb from 3–4 months old slaughtered at Aberystwyth, there occurred 75 individuals.The fact that lambs regularly harbour adult tapeworms before they are weaned suggests the possibility of their contracting the infection from the mother-ewes. No direct evidence in this direction has been obtained, however, and an attempt to produce a larval stage in the udder region of a ewe by feeding to it the eggs of a tapeworm proved abortive.Hitherto, all attempts to produce the adult tapeworms directly by feeding the eggs to sheep have failed; there is, however, the remote possibility that the eggs require to undergo some kind of maturation process outside the body of the sheep before they will develop. The fact that several species of Moniezia occur in the domestic sheep would seem to require an intermediate stage, which would occur in a corresponding number of intermediate-host species.The disease seems prevalent in flocks which are singularly free from ectoparasites.The invertebrates which seem most likely to harbour an intermediate stage are coprophagous insects, etc. (beetles, flies, mites). Attempts to infect species of Aphodius have nevertheless proved fruitless.Moisture favours the survival of the eggs of Moniezia: eggs kept in water for a period of several months seemed to remain perfectly viable. Nevertheless tapeworm is common among flocks on pastures about Rome which are characteristically dry.A comprehensive series of experiments under conditions of the most complete control would almost certainly clear up the life-history; on economic grounds alone the problem is urgent.The overwhelming majority of a quantity of worms collected from slaughter-houses in Aberystwyth, Aberdeen, Beauly (Inverness-shire) and Newcastle-on-Tyne proved to be of the species M. expansa. The only other species found were M. trigonophora and M. alba. The identification was based on anatomical characters and not on externals, which are useless.The writer intends directing his attention to coprophagous mites as carriers, viz. Gamasus coleoptratorum, G. fimetorum, Macrocheles glaber.


Parasitology ◽  
1933 ◽  
Vol 25 (3) ◽  
pp. 317-328 ◽  
Author(s):  
F. J. Brown

1. The life history of Lecithodendrium chilostomum has been established; C. Lecithodendrii chilostomi penetrates a second intermediate host, the larva of Phryganea grandis, and unlike other stylet cercariae does not encyst, but feeds and grows in the host tissue as a mobile metacercaria. During pupation of the host in the following year these mobile forms migrate from the abdominal segments of the larva to the thorax, where they then encyst in the thoracic muscles in which they are also found in the imago. The largest metacercariae and the excysted worms are typical early adult Lecithodendrium chilostomum. No case of progenesis in the metacercaria was found.2. It is estimated that the maximum swarming of the cercariae probably occurs during July, when first penetration of the intermediate host takes place. Subsequent diminished swarming and penetration proceed until November. The life of the larval trematode as a mobile metacercaria is approximately 8 months; the imagines of Phryganea grandis emerge during May and June, the infective period for the final host.3. The metacercariae are not distributed throughout the body cavity of their larval host, but the majority are confined to the three posterior segments.4. Limnophilus rhombicus may also serve as a second intermediate host, but the infection is very light and the metacercariae do not encyst during pupation of this host.5. The excretory system has been determined in all stages of Lecithodendrium chilostomum; it is of the 2 (6 × 2) type. The occurrence of this type of system in other groups of cercariae is reviewed and since it is found in several widely separated families, it is suggested that its presence does not necessarily imply relationship, but is due to convergence.6. The life histories of the following bat trematodes are indicated: Lecitho-dendrium lagena, Plagiorchis vespertilionis and Crepidostomum moeticus.7. The life history of Dicrocoelium dendriticum is discussed.


1917 ◽  
Vol 8 (2) ◽  
pp. 121-123 ◽  
Author(s):  
D. Keilin

It has been well known since the studies of Taschenberg (1864–1872) that the larvae of Leptohylemyia coarctata, Fall., attack wheat and rye. The damage due to this fly has been observed many times in almost all European countries, and many papers have been devoted to its life-history. Of these papers the most important are those of E. Ormerod (1882–1895), S. Rostrup (1905–1911), T. Hedlund (1906- 1907), P. Marchal (1909) and finally the recent work of Kurdjumov (1914).


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.


1961 ◽  
Vol 35 (S1) ◽  
pp. 53-62 ◽  
Author(s):  
J. A. Dinnik ◽  
N. N. Dinnik

A half a century ago, R. T. Leiper described a new species belonging to the genus Fasciola from specimens which he collected from hippopotami at the Murchison Falls, on the Victoria Nile in Uganda, in the summer of 1907. This species, Fasciola nyanzae, was found in the bile ducts of the liver, and in most instances the specimens were somewhat macerated owing to the length of time that had elapsed before the animal could be recovered from the water. Nevertheless, the characteristic shape of these liver flukes and the restriction of the branched testes to the anterior third of the body made it possible to recognise them as being different from all other species of the genus known at that time.


1906 ◽  
Vol 38 (12) ◽  
pp. 381-384
Author(s):  
James Fletcher ◽  
Arthur Gibson

In the Report of the Entomologist and Botanist to the Dominion Experimental Farms for 1905, at pages 179 and 180, considerable space is given to a discussion of an outbreak of a large noctuid caterpillar, which appeared in considerable numbers in Canada during 1905. Complaints of injury by this insect were received from a wide area, extending from Nova Scotia as far west as Lake Superior. During July many kinds of plants in gardens were attacked by smooth cutworm-like caterpillas, which when small were greenish in colour, having the body divided into two equal areas above and below the spiracles by a wide black stigmatal band.


1998 ◽  
Vol 15 (1) ◽  
pp. 41-63 ◽  
Author(s):  
David Johns

In this study the sociological and philosophical concept of the sport ethic has been utilized to explain the meaning of extreme and overconforming athlete behaviors which manifest themselves as athletic preparation. The study discloses, through the life history of a rhythmic gymnast, how the meanings and values of what it means to be an athlete were transmitted through the day-to-day discourse of athlete practice. By focusing on the dietary preoccupations of gymnasts involved in international competition, it was possible to demonstrate how modern sport preparation is not only distorted but also paradoxical, serving to push the body beyond its limits while insisting on its preservation.


Parasitology ◽  
1953 ◽  
Vol 43 (1-2) ◽  
pp. 148-159 ◽  
Author(s):  
B. Jobling

At one of the meetings of the Royal Society of Tropical Medicine and Hygiene, I made a very short communication on the three blood-sucking midges (Jobling, 1929). My particular reference was to Culicoides vexans, which is the most troublesome and commonestspecies in spring, in the northern and the north-western suburbs of London. At that time I had been studying the life history of this midge, including the morphology of its eggs, larvae and the pupa, but this work was not completed.


1922 ◽  
Vol 36 (1) ◽  
pp. 135-140 ◽  
Author(s):  
J. Homer Wright ◽  
Eugene M. Craighead

1. The attempt to infect young rabbits and guinea pigs with material containing in all probability the virus of human infantile paralysis failed. 2. Failure to infect the primary animals almost of necessity brought failure with the secondary flea-bitten animals. It is, however barely conceivable that a non-infectious form of an organism might circulate in the blood of the primary animal and that this form, through development in an intermediate host, the flea, might become virulent for the secondary flea-bitten animal. 3. Incidentally, and presumably accidentally, a paralytic disease was observed in young rabbits associated with the presence of an organism showing certain definite characters. So far as we know this paralysis and the associated organism have not been previously described. 4. This organism is found widely distributed in the organs of the affected animals and can be demonstrated in the urine. The active destruction by the organism of the nerve cells of the spinal cord is particularly striking, and gives complete explanation for the paralysis observed clinically. 5. With the organism present in the urine the spread of the disease by contact can be easily understood. 6. The transfer of the infection from animal to animal by fleabites is possible but not probable. 7. The nature of the observed organisms is in doubt. They represent probably an intermediate stage in the life history of some protozoan parasite.


1870 ◽  
Vol 2 (4) ◽  
pp. 43-44
Author(s):  
V. T. Chambers

Seeing in the last number of the Canadian Entomologist, a description of the egss of A. Luna, reminds me to ask of you the explanation of a curious circumstance in the life-history of one bred by me from the larva last year. I will premise that I am writing without my notes, and therefore cannot give figures accurately, but can give the facts. There may be nothing very strange about it, but two of the best entomologists in the United States inform me that it is entirely new to them. It is this:–Some time in the latter part of the summer of 1868 I took, feeding on walnut leaves, a mature larva of A. Luna; from which I did not houi to rear the mature insect, because I counted on the larva over twenty eggs like those of a Tachina, Underneath some of the eggs I could discern with a lens a minute opening through which the fly-larva had entered the body of the Luna larva. The skin of the latter was more or less discoloured under each egg, but under some-under many in fact there was a dense black spot, sometimes two lines in diameter.


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