STUDIES ON CESTODES OF THE GENUS TRIAENOPHORUS FROM FISH OF LESSER SLAVE LAKE, ALBERTA: IV. THE LIFE OF TRIAENOPHORUS CRASSUS FOREL IN THE SECOND INTERMEDIATE HOST

1945 ◽  
Vol 23d (4) ◽  
pp. 105-115 ◽  
Author(s):  
Richard B. Miller
Keyword(s):  
Intermediate Host ◽  
Lake Trout ◽  
Body Cavity ◽  
The Body ◽  
Coregonus Clupeaformis ◽  
Alternative Hosts ◽  
Pyloric Caeca ◽  
Drying Up ◽  
Second Intermediate Host

The plerocercoids of Triaenophorus crassus encyst normally in the flesh of fishes of the genus Leucichthys; the whitefishes, Coregonus clupeaformis and Prosopium oregonium, are common alternative hosts in Lesser Slave Lake. Elsewhere lake trout, Cristivomer namaycush, and possibly the inconnu, Stenodus leucichthys, may occasionally serve as hosts.The procercoids arrive in the stomach of their second intermediate host while in the body cavity of Cyclops bicuspidatus. When they are liberated by digestion, the majority apparently enter pyloric caeca, penetrate these, cross the body cavity, and enter the flesh, where encystment as the plerocercoid takes place. The evidence for these movements is only partial. The plerocercoids encyst in the flesh in July each year. They remain three or four years and then disappear by drying up or being reduced to small calcareous nodules.The number of plerocercoids per fish increases with the age of the fish up to five or six years.

Life cycles of species of Proteocephalus, parasites of fishes in the Palearctic Region: a review

1999 ◽  
Vol 73 (1) ◽  
pp. 1-19 ◽  
Author(s):  
T. Scholz
Keyword(s):  
Intermediate Host ◽  
Body Cavity ◽  
Life Cycles ◽  
The Body ◽  
Individual Species ◽  
Intermediate Hosts ◽  
Palearctic Region ◽  
Second Intermediate Host ◽  
Planktonic Crustaceans ◽  
Fish Hosts

The life cycles of species of Proteocephalus Weinland, 1858 (Cestoda: Proteocephalidea) parasitizing fishes in the Palearctic Region are reviewed on the basis of literary data and personal experimental observations, with special attention being paid to the development within the intermediate and definitive hosts. Planktonic crustaceans, diaptomid or cyclopid copepods (Copepoda), serve as the only intermediate hosts of all Proteocephalus species considered. A metacestode, or procercoid, develops in the body cavity of these planktonic crustaceans and the definitive host, a fish, becomes infected directly after consuming them. No previous reports of the parenteral location of metacestodes within the second intermediate host as it is in the Nearctic species P. ambloplitis have been recorded. Thus, the life cycles of Proteocephalus tapeworms resemble in their general patterns those of some pseudophyllidean cestodes such as Eubothrium or Bothriocephalus, differing from the latter in the presence of a floating eggs instead of possessing an operculate egg from which a ciliated, freely swimming larva, a coracidium, is liberated. The scolex of Proteocephalus is already formed at the stage of the procercoid within the copepod intermediate host; in this feature, proteocephalideans resemble caryophyllidean rather than pseudophyllidean cestodes. The morphology of procercoids of individual species is described with respect to the possibility of their differentiation and data on the spectrum of intermediate hosts are summarized. Procercoids of most taxa have a cercomer, which does not contain embryonic hooks in contrast to most pseudophyllidean cestodes. The role of invertebrates (alder-fly larvae — Megaloptera) and small prey fishes feeding upon plankton in the transmission of Proteocephalus tapeworms still remains unclear but these hosts are likely to occur in the life cycle. Data on the establishment of procercoids in definitive hosts, morphogenesis of tapeworms within fish hosts, and the length of the prepatent period are still scarce and new observations are needed. Whereas extensive information exists on the development of P. longicollis (syns. P. exiguus and P. neglectus), almost no data are available on the ontogeny of other taxa, in particular those occurring in brackish waters (P. gobiorum, P. tetrastomus). The morphology of P. cernuae and P. osculatus procercoids from experimentally infected intermediate hosts is described for the first time.

On the Excretory System and Life History of Lecithodendrium chilostomum (Mehl.) and other Bat Trematodes, with a Note on the Life History of Dicrocoelium dendriticum (Rudolphi)

Parasitology ◽  
1933 ◽  
Vol 25 (3) ◽  
pp. 317-328 ◽  
Author(s):  
F. J. Brown
Keyword(s):  
Life History ◽  
Intermediate Host ◽  
Life Histories ◽  
Body Cavity ◽  
The Body ◽  
Excretory System ◽  
Dicrocoelium Dendriticum ◽  
Larval Host ◽  
History Of ◽  
Second Intermediate Host

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.

The consequences of self-fertilization and outcrossing of the cestode Schistocephalus solidus in its second intermediate host

Parasitology ◽  
2003 ◽  
Vol 126 (4) ◽  
pp. 369-378 ◽  
Author(s):  
M. CHRISTEN ◽  
M. MILINSKI
Keyword(s):  
Intermediate Host ◽  
Gasterosteus Aculeatus ◽  
Life Stage ◽  
Life History Strategy ◽  
Body Cavity ◽  
Infected Fish ◽  
Mixed Mating ◽  
Schistocephalus Solidus ◽  
Self Fertilization ◽  
Second Intermediate Host

Many hermaphroditic parasites reproduce by both cross-fertilization and self-fertilization. To understand the maintenance of such mixed mating systems it is necessary to compare the fitness consequences of the two reproductive modes. This has, however, almost never been done in the context of host–parasite coevolution. Here we show the consequences of outcrossing and selfing in an advanced life-stage of the cestode Schistocephalus solidus, i.e. in its second intermediate host, the three-spined stickleback (Gasterosteus aculeatus). Each juvenile stickleback was simultaneously exposed to 2 experimentally infected copepods, one harbouring outcrossed the other selfed parasites. At 60 days p.i. parasites were removed from the fish's body cavity and, with microsatellite markers, assigned to either outcrossed or selfed origin. Prevalence was not significantly higher in outcrossed parasites. However, those fish that were infected contained significantly more outcrossed than selfed parasites. Thus the probability of a selfed parasite to progress in the life-cycle is reduced in the second intermediate host. Furthermore, we found that even the multiply infected fish increased in weight during the experiment. Nevertheless, total worm weight in multiply infected fish was significantly lower than in singly infected ones, which thus might be a parasite life-history strategy.

Encystment site affects the reproductive strategy of a progenetic trematode in its fish intermediate host: is host spawning an exit for parasite eggs?

Parasitology ◽  
2011 ◽  
Vol 138 (9) ◽  
pp. 1183-1192 ◽  
Author(s):  
KRISTIN K. HERRMANN ◽  
ROBERT POULIN
Keyword(s):  
Life Cycle ◽  
Intermediate Host ◽  
Body Cavity ◽  
Life Cycles ◽  
Temperature Changes ◽  
Fish Spawning ◽  
Second Intermediate Host ◽  
Host Life ◽  
Major Factors ◽  
Fish Hosts

SUMMARYEach transmission event in complex, multi-host life cycles create obstacles selecting for adaptations by trematodes. One such adaptation is life cycle abbreviation through progenesis, in which the trematode precociously matures and reproduces within the second intermediate host. Progenesis eliminates the need for the definitive host and increases the chance of life cycle completion. However, progenetic individuals face egg-dispersal challenges associated with reproducing within metacercarial cysts in the tissues or body cavity of the second intermediate host. Most progenetic species await host death for their eggs to be released into the environment. The present study investigated temporal variation of progenesis in Stegodexamene anguillae in one of its second intermediate fish hosts and the effect of the fish's reproductive cycle on progenesis. The study involved monthly sampling over 13 months at one locality. A greater proportion of individuals became progenetic in the gonads of female fish hosts. Additionally, progenesis of worms in the gonads was correlated with seasonal daylight and temperature changes, major factors controlling fish reproduction. Host spawning events are likely to be an avenue of egg dispersal for this progenetic species, with the adoption of progenesis being conditional on whether or not the parasite can benefit from fish spawning.

Sites of encystment by the metacercariae of Echinoparyphium recurvatum in Lymnaea peregra

1992 ◽  
Vol 66 (2) ◽  
pp. 96-99 ◽  
Author(s):  
M. E. Adam ◽  
J. W. Lewis
Keyword(s):  
Intermediate Host ◽  
Experimental Infection ◽  
Mantle Cavity ◽  
The Body ◽  
Visceral Mass ◽  
Pericardial Cavity ◽  
Second Intermediate Host ◽  
Lymnaea Peregra

ABSTRACTExperimental infection of Echinoparyphium recurvatum von Linstow (Digenea: Echinostomatidae) cercariae in the snail second intermediate host Lymnaea peregra Müller shows that metacercarial encystment takes place on the lining of the mantle cavity, pericardial cavity and kidney lumen, with the mantle cavity the most preferred site. All three sites are accessible via the body openings. The metacercariae appear to be more susceptible to encapsulation in the visceral mass than in the cavity of the mantle, pericardium and the lumen of the kidney.

Studies on the life-cycle of Himasthla militaris(Trematoda: Echinostomatidae)

Parasitology ◽  
1980 ◽  
Vol 81 (3) ◽  
pp. 609-617 ◽  
Author(s):  
R. Vanoverschelde ◽  
F. Vaes
Keyword(s):  
Intermediate Host ◽  
The Body ◽  
Exogenous Factor ◽  
Specific Distribution ◽  
Temperature Environment ◽  
Second Intermediate Host ◽  
Anterior Segments ◽  
External Migration ◽  
First Intermediate Host ◽  
Cercarial Emergence

SUMMARYIn this study two aspects of the biology of the cercaria of Himasthla militaris were examined. Firstly, the cercarial emergence from the first intermediate host, Hydrobia stagnorum, was studied. On a 9 h light (9L)/15 h dark (15D) schedule cercariae of Himasthla militaris emerged from naturally infected Hydrobia stagnorum predominantly during darkness. Inversion of the photo-period resulted in an immediate reversal of the emergence pattern. A comparison between the cercarial release patterns under natural conditions and in a constant light/temperature environment showed that an endogenous as well as an exogenous factor is controlling this process. Secondly, the penetration of the cercaria in Nereis diversicolor and the site-finding of the larva within this second intermediate host was investigated. After a short external migration on the body of N. diversicolor the cercaria enters the polychaete via the anus opening, perforates the gut-wall and moves through the coelom to the anterior segments to encyst in the muscle tissue. This internal migration results in a specific distribution pattern of the metacercariae, with more than 50% of the cysts localized in the first 12 segments and a maximum in segment number 9 (13·8%).

scholarly journals Angiostrongylus costaricensis and the intermediate hosts: observations on elimination of L3 in the mucus and inoculation of L1 through the tegument of mollucs

1998 ◽  
Vol 31 (3) ◽  
pp. 289-294 ◽  
Author(s):  
Vera Cristina Brandão Diniz de Oliveira Bonetti ◽  
Carlos Graeff-Teixeira
Keyword(s):  
Intermediate Host ◽  
Parasitic Nematode ◽  
Body Cavity ◽  
The Body ◽  
Productive Infection ◽  
Intermediate Hosts ◽  
Preliminary Trial ◽  
Abdominal Disease ◽  
Complex Procedure ◽  
Kinetics Of

Human accidental infection with Angiostrongylus costaricensis may result in abdominal disease of varied severity. Slugs from the Veronicellidae family are the main intermediate hosts for this parasitic nematode of rodents. Phyllocaulis variegatus, Phyllocaulis soleiformis and Phyllocaulis boraceiensis were experimentally infected to describe the kinetics of L3 elimination in the mucus secretions of those veronicelid species. A maximum of 2 L3/g/day was found in the mucus, while the number of L3 isolated from the fibromuscular tissues varied from 14 to 448. Productive infection was established by inoculations in the hyponotum or in the body cavity, through the tegument. Intra-cavity injection is a less complex procedure and permits a better control of inocula. A preliminary trial to titrate the infective dosis for P. variegatus indicated that inocula should range between 1000 and 5000 L1. The data also confirmed the importance of P. variegatus as an intermediate host of A. costaricensis.

Changes in Maturity, Plasma Sex Steroid Levels, Hepatic Mixed-Function Oxygenase Activity, and the Presence of External Lesions in Lake Whitefish (Coregonus clupeaformis) Exposed to Bleached Kraft Mill Effluent

1992 ◽  
Vol 49 (8) ◽  
pp. 1560-1569 ◽  
Author(s):  
K. R. Munkittrick ◽  
M. E. McMaster ◽  
C. B. Portt ◽  
G. J. Van Der Kraak ◽  
I. R. Smith ◽  
...  
Keyword(s):  
Pulp Mill ◽  
Gonadal Development ◽  
Body Cavity ◽  
The Body ◽  
Coregonus Clupeaformis ◽  
Lake Whitefish ◽  
Liver Size ◽  
Kraft Mill Effluent ◽  
Kraft Mill ◽  
Mixed Function Oxygenase

Lake whitefish (Coregonus clupeaformis) exposed to primary treated bleached kraft mill effluent (BKME) had reduced gonadal development and increased liver size relative to two reference populations. These results parallel our previous work on the white sucker (Catostomus commersoni) exposed to BKME at the same Lake Superior site. More detailed studies conducted in 1990, after the installation of an aeration stabilization basin at the pulp mill, found that lake whitefish exhibited reduced gonad sizes, delayed age to maturation, decreased levels of the plasma sex steroids testosterone and 17β-estradiol, and elevated hepatic mixed-function oxygenase (MFO) activity. Liver size was smaller following operation of the secondary treatment system. More than 20% of the lake whitefish collected at the BKME site in 1990 exhibited lateral, slash-like lesions which penetrated the body cavity. Histological examination revealed no evidence of an infectious etiology, and the wounds could not be accounted for by known causes. Similar lesions were found in 1991 near a second BKME discharge.

Development and infectivity of the procercoid of Triaenophorus crassus Forel and mortality of the first intermediate host

1983 ◽  
Vol 61 (9) ◽  
pp. 2120-2128 ◽  
Author(s):  
R. Rosen ◽  
T. A. Dick
Keyword(s):  
Intermediate Host ◽  
Negative Binomial ◽  
Coregonus Clupeaformis ◽  
Factors Influencing ◽  
Percent Recovery ◽  
Second Intermediate Host ◽  
The Mean ◽  
Coregonus Artedii ◽  
First Intermediate Host ◽  
Over Time

Mortality of Cyclops bicuspidatus thomasi infected with the procercoid of Triaenophorus crassus was assessed and factors influencing the infectivity of the procercoid to the second intermediate host were evaluated. Over 80% of C. b. thomasi infected with T. crassus died after 28 days, and there was a bimodal pattern to cyclopid mortality. A decrease in the mean intensity over time indicated that this mortality was related to parasite numbers. The frequency of T. crassus in C. b. thomasi after 28 days fitted the negative binomial distribution. A higher proportion of lightly infected cyclopids at this time resulted from mortality of heavily infected hosts. Female cyclopids had larger procercoids than males, but the ratio of differentiated to undifferentiated procercoids did not vary between sexes. Procercoid size was smaller and the proportion of differentiated procercoids decreased with increasing intensities of infection. Exposure of laboratory-reared whitefish, Coregonus clupeaformis, and cisco, Coregonus artedii, to procercoids from crowded infections resulted in a low percent recovery of plerocercoids, while less crowded infections of procercoids produced a high percent recovery of plerocercoids in fish. The number of procercoids to which fish were exposed affected the percent recovery of plerocercoids.

The function of the paraoesophageal glands in an echinostome (digenean) cercaria (? Cercaria spinifera La Valette, 1855)

1989 ◽  
Vol 63 (3) ◽  
pp. 231-238 ◽  
Author(s):  
G. Cleveland ◽  
G. C. Kearn
Keyword(s):  
Intermediate Host ◽  
The Body ◽  
Intermediate Hosts ◽  
Host Preferences ◽  
Planorbarius Corneus ◽  
Second Intermediate Host ◽  
First Time

ABSTRACTAn echinostome cercaria (? Cercaria spinifera La Valette, 1855) with 37 collar spines and paraoesophageal glands has been recorded for the first time in Britain from the gastropod Planorbarius corneus. The cercariae penetrate into and encyst in planarians. Observations made on cercariae during penetration indicate that the paraoesophageal glands are used to enter the body of the planarian and that the so-called penetration glands have some other function. Gastropod molluscs may also serve as second intermediate hosts, but there is evidence to indicate that anatomically similar cercariae from different host individuals vary in their second intermediate host preferences.

Sign in / Sign up

Export Citation Format

Share Document