On the life cycle of Diorchis bulbodes Mayhew, 1929 (Cyclophylhdea: Hymenolepididae), a parasite of waterfowl (Anseriformes: Anatidae)

1993 ◽  
Vol 71 (8) ◽  
pp. 1697-1699 ◽  
Author(s):  
T. A. Greaves ◽  
M. D. B. Burt ◽  
W. Pilgrim

During a survey of parasites of waterfowl, collected in New Brunswick during the hunting seasons of 1987 and 1988, the small intestine of one male wood duck, Aix sponsa, was found to contain 32 specimens of the cestode Diorchis bulbodes. After several repeated experimental infections of various crustaceans, full development of a tailed cysticercoid occurred in the ostracod Cypridopsis vidua.

1989 ◽  
Vol 67 (2) ◽  
pp. 502-504 ◽  
Author(s):  
T. A. Greaves ◽  
L. Jarecka ◽  
M. D. B. Burt

Between October 2, 1985, and November 16, 1986, 129 muskrats, Ondatra zibethica were collected in New Brunswick and examined for parasites. Forty-one of the muskrats harboured the the cestode Hymenolepis evaginata in the small intestine, with infections ranging from 1-10 worms per host. To determine the intermediate host of H. evaginata, a number of aquatic and terrestrial invertebrates were exposed to oncospheres in the laboratory. Full development of a tailed cysticercoid only occurred in the ostracod Cyclocypris laevis. The cysticercoid undergoes typical protocepyhalic development in this micro-crustacean. This characteristic, regarded as primitive, occurs in hymenolepidids found in aquatic birds. It appears that although this cestode is commonly found in mammals, it is more closely related to aquatic avian hymenolepidids than to those found in terrestrial mammals.


1963 ◽  
Vol 41 (5) ◽  
pp. 881-888 ◽  
Author(s):  
Hilda Lei Ching

Maritrema laricola sp. n. from the intestine of the glaucous-winged gull, Larus glaucescens, differs from other species in the genus in having an elongate body, small cirrus sac, and short, curved cirrus. The life cycle of the species was followed from sporocyst stage in Littorina scutulata and Littorina sitchana, to the metacercarial stage in Hemigrapsus oregonensis and H. nudus, and to the adult in natural and experimental hosts. In experimental infections of H. oregonensis, the cercariae penetrate and develop in the gills after which they migrate to the haemocoel of the crab and encyst. The metacercariae are fully developed in from 6 to 9 weeks, and similar in size and morphology to natural infections in crabs. Excystment of the metacercariae occurs in the following cultures at 40 °C: 3% pepsin plus 1% HCl, 0.85% saline, and seawater diluted 1:4. Metacercariae live for about 3 days in diluted seawater but do not produce eggs in any of the cultures. Only immature worms were recovered from mice and newly hatched chicks when they were fed the metacercariae, but mature worms were found in natural and experimental infections of the glaucous-winged gull. In a review of the genus Maritrema, the following transfers are made: Maritrema uca Sarkisian, 1957 to the genus Mecynophallus Cable, Connor, and Balling, 1960, and Maritreminoides raminellae Dery, 1958 to Pseudospelotrema Yamaguti, 1939.


1967 ◽  
Vol 45 (6) ◽  
pp. 1255-1260 ◽  
Author(s):  
C. S. Shanta ◽  
E. Meerovitch

In experimental infections in mice, Trichinella spiralis larvae in the intestines molted twice before reaching sexual maturity. In both sexes, the first molt occurred between 12 and 16 hours post infection; in males, the second molt occurred between 24 and 32 hours, and in females, between 22 and 30 hours. The females were inseminated after the 36th hour post infection, but some males had spermatozoa in the seminal vesicles before the completion of the second molt. Structures, believed to be amphids, were observed after 2 hours post infection; they increased in size up to the 6th hour, after which they regressed and finally disappeared. The function of these amphids is believed to be related to osmoregulation.


2017 ◽  
Vol 48 (4) ◽  
pp. 193-201 ◽  
Author(s):  
A. Brožová ◽  
I. Jankovská ◽  
V. Bejček ◽  
S. Nechybová ◽  
P. Peřinková ◽  
...  

Abstract Species of the genus Echinococcus (Cestoda; Taeniidae) are minute tapeworms of carnivores. Their larvae are known as hydatids (metacestode), which proliferate asexually in various mammals. Like the majority of cestodes, Echinococcus spp. require two different host species to complete their life cycle. Definitive hosts harbouring the adult cestodes in the small intestine are exclusively carnivores of the Canidae and Felidae families. A wide range of mammal species including humans is susceptible to infection by the metacestode of Echinococcus spp., which develops in their viscera. The disease, caused by species of the genus Echinococcus, is called echinococcosis, and it is one of the most dangerous zoonoses in the world. The traditional species Echinococcus granulosus and Echinococcus multilocularis are agents of significant diseases due to the high number of cases and the wide geographical species range. The taxonomy of the genus is controversial; in the current state of ongoing complex revisions, the agent of cystic echinococcosis E. granulosus sensu lato is divided into five species (E. granulosus sensu stricto, E. felidis, E. equinus, E. ortleppi, E. canadensis), in addition to the agents of alveolar echinococcosis (E. multilocularis, E. shiquicus) and polycystic/unicystic echinococcosis (E. vogeli, E. oligarthrus). Here we provide an overview of the current situation, which continues to develop.


1995 ◽  
Author(s):  
Gary R. Hepp ◽  
Frank C. Bellrose
Keyword(s):  

1975 ◽  
Vol 53 (8) ◽  
pp. 1110-1115 ◽  
Author(s):  
D. H. Steele ◽  
V. J. Steele

Gammarus finmarchicus is an amphi-Atlantic species. In the western Atlantic it is found from the island of St. Pierre south to Long Island Sound. At St. Andrews, New Brunswick, 50% maturity occurs at 10.5 mm in the females. Reproduction is in progress throughout the year, but small females evidently are in a resting condition during September–October before breeding. The release of young by the population is greater in the spring, summer, and early autumn than it is in late autumn and winter. The young released in the spring and summer do not reproduce until the next year so that the life cycle is annual.


1973 ◽  
Vol 51 (7) ◽  
pp. 781-786 ◽  
Author(s):  
Dwight R. Mudry ◽  
Hisao P. Arai

The life cycle of Hunterella nodulosa Mackiewicz and McCrae, 1962 is described. Eggs contain oncospheres after 15–16 days at 20 °C. The pattern of growth in size and organ development of procercoids in experimentally infected Limnodrilus udekemianus is described. Catostomus commersoni was successfully infected with procercoids from experimental infections, and development of adults was followed for 50 days. The pattern of growth in size and organ development for adult H. nodulosa is illustrated.


Parasitology ◽  
1967 ◽  
Vol 57 (2) ◽  
pp. 351-361 ◽  
Author(s):  
P. L. Long

E. praeox has been isolated in Britain for the first time and is similar in regard to its oocyst size, prepatent time, life-cycle and the development of host immunity to the reports of Tyzzer et al. (1932). Oocysts had mean dimensions of 20·4 × 17·45 μm and the first oocysts were discharged 83½ h after infection.Oocyst production and life-cycle studies suggest that at least three generations of schizogony precede gametogony and that at least one further generation of schizogony is needed to explain the oocyst reproduction resulting from a small dose of oocysts. Young chickens 1½–3 weeks of age were not such suitable hosts as older chickens (6 weeks) and the reproduction of the parasite was seriously reduced when large numbers (e.g. 105, 106) were used to infect chickens. A high degree of resistance to reinfection occurred after a single exposure to infection.Sporozoite infections of the caeca or cloaca resulted in the infection of the usual small intestine site; there was no development at the site of inoculation and attempts to infect the embryo allantois did not succeed.I wish to thank Dr M. Elaine Rose for the surgery required for the caecal infections, for her interest throughout and for help with the manuscript; Dr R. F. Gordon for help with the manuscript and permission to publish and Mr B. J. Millard for skilled technical assistance.


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