scholarly journals EMERGENCE OF THIRD-STAGE LARVAE OF UMINGMAKSTRONGYLUS PALLIKUUKENSIS FROM THREE GASTROPOD INTERMEDIATE HOST SPECIES

2000 ◽  
Vol 86 (4) ◽  
pp. 743 ◽  
Author(s):  
S. J. Kutz ◽  
E. P. Hoberg ◽  
L. Polley
1999 ◽  
Vol 77 (10) ◽  
pp. 1562-1572 ◽  
Author(s):  
S J Kutz ◽  
E P Hoberg ◽  
L Polley

Three captive muskoxen (Ovibos moschatus) were successfully infected with third-stage larvae of Umingmakstrongylus pallikuukensis digested or emerged from the slugs Deroceras reticulatum and D. laeve, for the first time completing the life cycle of this parasite under experimental conditions. The course of parasite development and patency was followed for 26 months post infection (p.i.) using fecal examinations and radiography. The prepatent periods in two of the muskoxen were 91 and 95 days and the patent period in one extended for 23 months. Larval production peaked 13-14 months p.i. On postmortem of two of the muskoxen at months 14 and 26 p.i., adult parasites were found only within pulmonary cysts and cysts were randomly distributed between left and right lungs. Cyst dimensions were positively correlated with the number of adult parasites they contained. On postmortem of the third muskox at day 97 p.i., not all adult parasites were within typical cysts; two were found free in interlobular septa. First-stage larvae were recovered from lung cysts of this animal but not from feces. Lung pathology in all three muskoxen appeared localized and associated with the adult nematodes. Infection of two sheep with third-stage larvae of U. pallikuukensis did not result in parasite establishment.


1999 ◽  
Vol 73 (2) ◽  
pp. 143-145 ◽  
Author(s):  
A.M. McCarthy

The potential influence of second intermediate host species on the infectivity of metacercarial cysts of Echinoparyphium recurvatum to the definitive host Anas platyrhynchos was examined experimentally. Echinoparyphium recurvatum metacercarial cysts were obtained from the following experimentally infected second intermediate hosts 14 days post expsoure to cercariae: Lymnaea peregra; Physa fontinalis; L. stagnalis;Planorbis planorbis; Biomphalaria glabrata; tadpoles of the amphibian Rana temporaria. Metacercarial cysts from each of these hosts were fed, in doses of 50 cysts per individual, to separate groups composed of between four and eight, 3-day-old A. platyrhynchos ducklings. All A. platyrhynchos were necropsied 15 days post-infection and the number, size, and reproductive status of E. recurvatum worms in the intestine was recorded. Analyses of variance on the number (transformed log (x + 1)) and size of worms revealed no significant differences in worms originating from metacercariae formed in the different second intermediate hosts (worm number P > 0.05, and worm size P > 0.05). All worms recovered were found to be gravid. It is therefore concluded that the species of second intermediate host utilized does not influence the infectivity of the metacercarial cyst of E. recurvatum, nor the subsequent establishment and reproductive status of the parasite in A. platyrhynchos.


1992 ◽  
Vol 34 (4) ◽  
pp. 277-287 ◽  
Author(s):  
Dulcinéa Maria Barbosa Campos ◽  
Lindomar G. Freire Filha ◽  
Miguel Alípio Vieira ◽  
Julieta Machado Paçô ◽  
Moacir A. Maia

The life cycle of Lagochilascaris minor was studied using material collected from human lesion and applying the experimental model: rodents (mice, hamsters), and carnivorae (cats, dogs). In mice given infective eggs, orally, hatch of the third stage larvae was noted in the gut wall, with migration to liver, lungs, skeletal musculature and subcutaneous tissue becoming, soon after, encysted. In cats infected with skinned carcasses of mice (60 to 235 days of infection) it was observed: hatch of third stage larvae from the nodules (cysts) in the stomach, migration through the oesophagus, pharynx, trachea, related tissues (rhino-oropharynx), and cervical lymphonodes developing to the mature stage in any of these sites on days 9-20 post inoculation (P.I.). There was no parasite development up to the mature stage in cats inoculated orally with infective eggs, which indicates that the life cycle of this parasite includes an obligatory intermediate host. In one of the cats (fed carcass of infected mice) necropsied on day 43 P.I., it was observed the occurence of the self-infective cycle of L. minor in the lung tissues and in the cervical region which was characterized by the finding of eggs in different stages of development, third stage larvae and mature worms. It's believed that some component of the carnivorae gastrointestinal tracts may preclude the development of third stage larvae from L. minor eggs what explains the interruption of the life cycle in animals fed infective eggs. It's also pointed out the role of the intermediate host in the first stages of the life cycle of this helminth.


2005 ◽  
Vol 79 (2) ◽  
pp. 169-176 ◽  
Author(s):  
J.A. Shears ◽  
C.R. Kennedy

AbstractPrevious studies on the life history of the nematode eel specialist Paraquimperia tenerrima (Nematoda: Quimperiidae) have failed to determine whether an intermediate host is required in the life cycle. In the laboratory, eggs failed to hatch below 10°C, hatching occurring only at temperatures between 11 and 30°C. Survival of the free-living second stage larvae (L2) was also temperature dependent, with maximal survival between 10 and 20°C. Total survival of the free-living stages (eggs and L2) is unlikely to exceed a month at normal summer water temperatures, confirming that parasite could not survive the 6 month gap between shedding of eggs in spring and infection of eels in early winter outside of a host. Eels could not be infected directly with L2, nor could a range of common freshwater invertebrate species. Third stage larvae (L3) resembling P. tenerrima were found frequently and abundantly in the swimbladder of minnows Phoxinus phoxinus from several localities throughout the year and were able to survive in this host in the laboratory for at least 6 months. Third stage larvae identical to these larvae were recovered from minnows experimentally fed L2 of P. tenerrima, and eels infected experimentally with naturally and experimentally infected minnows were found to harbour fourth stage larvae (L4) and juvenile P. tenerrima in their intestines. Finally, the whole life cycle from eggs to adult was completed in the laboratory, confirming that minnows are an obligate intermediate host for P. tenerrima.


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.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Fabio Marino ◽  
Giovanni Lanteri ◽  
Annamaria Passantino ◽  
Carmelo De Stefano ◽  
Antonella Costa ◽  
...  

The endoscopic and histopathological findings detected inSparus aurataexperimentally infected with third-stageAnisakislarvae without intermediate host are evaluated and discussed. In six fish, live nematode larvae were introduced by gastroscopy into the stomach. The first observation by endoscope, 15 days after challenge, showed the presence of some larvae at the level of gastric mucosa. An explorative celioscopy, performed 60 days after challenge, showed haemorrhages and/or nodules on the gut of two fishes. Necropsy and histology demonstrated parasites in the context of the tissue changes. The finding of live nematode larvae as well as the evidence of tissue change confirm the experimental susceptibility of gilthead sea bream towardsAnisakis.


1969 ◽  
Vol 43 (1-2) ◽  
pp. 207-222 ◽  
Author(s):  
J. J. Willemse

The present paper deals with investigations on the occurrence in Netherlands' fresh water fishes and host specificity of tapeworms belonging to the genus Proteocephalus. The species involved are:P. tetrastomus (Rudoiphi, 1810) in smelt, Osmerus eperlanus.P. longicollis (Zeder, 1800) in smelt, Osmerus eperlanus.P. cernuae (Gmelin, 1790) in pope, Acerina cernua.P. ocellatus (Rudolphi, 1802) in perch, Perca fluviatilis.P. macrocephalus (Creplin, 1825) in eel, Anguilla anguilla.Seasonal cycles were found in P. telrastomus and P. ocellalus; in the latter species this was certainly induced by low winter temperatures.Experimental infections showed that a high degree of host specificity exists in all species considered. Infections of an alien host were never successful. Two kinds of infections were carried out: (a) feeding plerocercoids (in the intermediate host), coming from a known source, to a number of fishes, belonging to several species including the original host species, and (b) transplanting worms, collected from the intestine of a fish, to the intestines of a number of other fishes, belonging to several species including the original host species.Notwithstanding the high degree of host specificity, worms may survive for one or two days, but usually in a bad condition, in the intestine of an alien host. Occasionally they survived up to 14 days: e.g. P. tetratomus in Anguilla anguilla. Consequently sometimes dissections of predator fishes or carrion eating fishes may produce dubious host records because actually Proteocephalus from their prey are recorded. We are convinced that P. tetrastomus found in Salmo trutta, Platichihys flesus and Perca fluviatilis originate from Osmerus eperlanus having been eaten by these species.Additionally cannibalism may be responsible for the fact that large specimens of some fish species, e.g. smelt, are heavily infected with Proteocephalus while they hardly eat any Cyclops, the intermediate host. This is clearly demonstrated by the transplantation experiments, transplanting worms to the proper host.From the data recorded it is apparent that representatives of the genus Proteocephalus are not harmful to commercially important fishes in the Netherlands. In these fishes natural infection with the proper species of Proteocephalus is low and successful infection with other species, showing a high incidence in less valuable fishes, is prevented by the high degree of host specificity. Additionally worms of the species studied did not injure the tissues of the intestinal wall by the action of their suckers and piercing of the intestinal wall never occurred. Even smelts infected with large numbers of worms-more than 50 in a single 20 cm. specimen-did not show any abnormalities in genital development or in the amount of fat in the body cavity.


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