Development of Syncuaria squamata (Linstow, 1883) (Nematoda: Acuarioidea) in ostracods (Ostracoda) and double-crested cormorants (Phalacrocorax auritus auritus)

1987 ◽  
Vol 65 (10) ◽  
pp. 2524-2531 ◽  
Author(s):  
P. L. Wong ◽  
R. C. Anderson
Keyword(s):  
Room Temperature ◽  
Gravid Female ◽  
Final Host ◽  
Mature Male ◽  
Phalacrocorax Auritus ◽  
Larval Stages ◽  
The Third ◽  
Third Stage ◽  
Cypridopsis Vidua ◽  
Freshwater Ostracods

Syncuaria squamata (Linstow) developed to the infective third stage in two species of freshwater ostracods (Cyclocypris ovum (Jurine) and Cypridopsis vidua (Muller)). At room temperature (19–21 °C) the first moult occurred 11 d and the second moult 18 d postinfection. In experimentally infected double-crested cormorants (Phalacrocorax auritus auritus (Lesson)) larval stages of S. squamata were found between folds of the proventriculus and underwent the third moult within 3.5 d and the fourth moult within 8 d postinfection. Mature male and gravid female worms were found under the gizzard lining at 29 d postinfection; some females were embedded in the gizzard musculature with their tails protruding into the lumen. First through fourth larval stages are described. Of 14 cormorants captured at 5 weeks of age from Pigeon Island, Lake Ontario, 13 (93%) were naturally infected with S. squamata. Five of these birds, 15 weeks or older when examined, harboured only mature male S. squamata. This suggests that female worms may become senescent before males. It is estimated that S. squamata has a life-span of about 4 months in its final host.

Studies on the life-history of Bunostomum phlebotomum (Railliet, 1900), a hookworm parasite of cattle

Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 192-201 ◽  
Author(s):  
J. F. A. Sprent
Keyword(s):  
Infective Larva ◽  
Stage Larva ◽  
Fourth Stage ◽  
Larval Stages ◽  
The Third ◽  
Third Stage ◽  
History Of ◽  
Time Required ◽  
Cutaneous Blood ◽  
Fourth Stage Larva

A description is given of the processes of copulation, formation of the egg and spermatozoon, cleavage, embryogeny and hatching in B. phlebotomum. These processes were found to be essentially similar to those in other strongyle nematodes.The anatomy of the first three larval stages is described and the observations of Conradi & Barnette (1908) and Schwartz (1924) were largely confirmed.Penetration of the skin of calves by the infective larva was observed histologically. The larvae were found to have reached the dermis within 30 min. and to have penetrated the cutaneous blood vessels within 60 min. of application to the skin. The larvae were found in the lung where the third ecdysis was in progress 10 days after penetration of the skin. A description is given of the growth of the third-stage larva in the lung, the changes which take place during the third ecdysis, and the anatomy of the fourth-stage larva.The fourth-stage larvae exsheath in the lungs and travel to the intestine. After a period of growth in which sexual differentiation takes place, the fourth ecdysis occurs and the adult parasite emerges. The time required for the attainment of maturity was found to be somewhere between 30 and 56 days after penetration of the skin.This paper was written at the Ministry of Agriculture and Fisheries Veterinary Laboratories, Wey-bridge, and the writer would like to express his gratitude to the Director, Prof. T. Dalling, also to Dr W. R. Wooldridge, chairman of the Council of the Veterinary Educational Trust for their help and encouragement. The writer's thanks are also due to Dr H. A. Baylis, Prof. R. T. Leiper and Dr E. L. Taylor for their advice and help on technical points, and to Mr R. A. O. Shonekan, African laboratory assistant, for his able co-operation.

Intercalation of pentane into the stage 2 to 4 cesium graphitides: Relation between cesium density in the intercalated layers and the stage of the parent binary

1993 ◽  
Vol 8 (9) ◽  
pp. 2288-2298 ◽  
Author(s):  
H. Pillière ◽  
M. Goldmann ◽  
F. Béguin
Keyword(s):  
Room Temperature ◽  
Three Dimensional ◽  
Structural Transformations ◽  
Layer Model ◽  
Simultaneous Formation ◽  
Ternary Compounds ◽  
Second Stage ◽  
The Third ◽  
Cesium Ions ◽  
Third Stage

Isotherms (at 300 K and 328 K) and isobars (in the range 300 to 400 K) of n-pentane intercalation in CsC24 and CsC36 were established. With CsC24, three plateaus were identified at 0.52, 0.7, and 1.0 n-pentane/24 C, whereas only two plateaus at 0.8 and 0.97 n-pentane/36 C were found with CsC36. The progress of the reaction between n-pentane and CsC24, CsC36, and CsC56 (stage 2 to 4) was monitored by real-time neutron diffraction. The intercalation of n-pentane in CsC24 results in the simultaneous formation of a second stage ternary and a first stage binary “CsC8”, whereas, from the third stage CsC36 or the fourth stage CsC56, only pure second stage or third stage ternary compounds are formed, respectively. Owing to the formation of binary domains rich in alkali metal (CsC8) or to stage lowering produced by the ternarization, the in-plane cesium density is smaller in the ternary layer than in the starting binary. The electrostatic repulsion between the cesium ions, provoked by the sorption of n-pentane, is believed to be at the origin of the increased coverage. During the intercalation or de-intercalation processes, three-dimensional segregation occurs in each grain. A pleated layer model with canted fronts is presented. It accounts for the various phases present within each grain and for the structural transformations caused by pressure variations. At room temperature, the ternary layer seems to be disordered. The order-disorder transition appearing either by decreasing the temperature or by increasing the n-pentane pressure is correlated to a hindered motion of the intercalated molecules.

Biology, morphology and anatomy of aphidophagous syrphid larvae

Parasitology ◽  
1939 ◽  
Vol 31 (1) ◽  
pp. 78-120 ◽  
Author(s):  
Madan Lal Bhatia
Keyword(s):  
Comparative Morphology ◽  
The Body ◽  
Individual Species ◽  
Larval Stages ◽  
The Third ◽  
Third Stage ◽  
Mode Of Life ◽  
Pass Through ◽  
The Individual ◽  
Syrphid Larvae

The paper deals with the biology, morphology and anatomy of seven species of syrphid larvae viz. Syrphus luniger Meig., S. balteatus De Greer, S. ribesii Linne, Catabomba pyrastri Linne, Sphaerophoria flavicauda Zett., Sph. scripta Linne, and Platychirus scutatus Meig.The habitat, mode of progression, aphidophagous habits and characteristic coloration are described for each species.It is shown that the larvae of all the above species, like larvae of other cyclorrhaphous Diptera, definitely pass through three stages separated by two moults. The mode of dehiscence of the puparium is described briefly.Each of the species, except Catabomba pyrastri, has three generations in the breeding season which lasts from May to October. Platychirus scutatus hibernates only in the larval stage, but the other species may be found in both the larval and pupal stages during the winter.The larvae of all the above species, except Syrphus balteatus, are commonly parasitized by ichneumonid larvae.The morphology of the egg, the three larval stages and the puparium of S. luniger is described in detail.The characters common to the third stage larvae of all the species dealt with are summarized and short descriptions of the third stage larvae and puparia of the individual species are given. The general appearance of the living larvae and details of the buccopharyngeal armature, spiracles and puparia of each of the species is represented in figures.In connexion with the pupae a number of new structures are described and it is suggested that some of them are concerned with the formation of the characteristic shape of the puparium and with the dehiscence of the puparium.Internal pupal spiracles are present in all the species dealt with, but external pupal spiracles are present only in Platychirus scutatus.The anatomy of P. scutatus is described and figured, an account being given of all the structures except the musculature of the body wall. Study of the anatomy affords evidence as to the carnivorous mode of life of the larvae and also indicates that the larvae have evolved from aquatic forms.The comparative morphology of the Syrphinae is discussed with respect to the relationship of the Syrphinae to other Aschiza and to the cyclorrhaphous Diptera.

Morphometric and morphological characteristics for identifying the life stages of Xiphinema bakeri Williams, 1961 (Nematoda: Longidorinae)

1970 ◽  
Vol 48 (4) ◽  
pp. 771-773 ◽  
Author(s):  
Jack R. Sutherland ◽  
T. G. Dunn ◽  
N. Bruce F. Cousens
Keyword(s):  
Morphological Characteristics ◽  
The Body ◽  
Life Stages ◽  
Larval Stages ◽  
Second Stage ◽  
The Third ◽  
Clear Area ◽  
Third Stage ◽  
Tail Shape ◽  
Tail Tip

Several morphometric and morphological characteristics were evaluated to determine their usefulness in identifying the life stages of Xiphinema bakeri. The stages can be identified by length of the body, onchiostylet, and replacement stylet of larvae. These values increase lineally from first-stage larva to adult, and fall into five groups corresponding to the nematodes' four larval stages and adult. Each stage has a specific tail-tip shape, which gradually changes from subacute in the first and second stages to subdigitate in adults. At lower magnifications, the body length and the tail shape, used in combination, are best for identification. First-stage larvae also have the replacement stylet overlapping the stylet extension, distinguishing them from the second stage. Frequently the immature vagina of fourth-stage larvae appears as a clear area in the body; this helps to separate them from the third stage.

The effect of constant and changing temperatures on the development of the eggs and larvae of Oswaldocruzia filiformis (Nematoda: Trichostrongyloidea)

1988 ◽  
Vol 62 (4) ◽  
pp. 281-292 ◽  
Author(s):  
Christine T. Griffin
Keyword(s):  
Room Temperature ◽  
Rana Temporaria ◽  
Free Living ◽  
Temperature Changes ◽  
Larval Stages ◽  
The Third ◽  
Temperature Regimes ◽  
Frog Tadpoles ◽  
Eggs And Larvae ◽  
Duration Of Development

AbstractThe free-living stages of Oswaldocruzia filiformis were cultured in tapwater under constant and changing temperature regimes. Embryonation and hatching proceeded at constant temperatures from 6° to 32°C; development of larvae to the third (infective) stage occurred between 6° and 34°C. The duration of development decreased with increased temperatures up to 28°C. The duration of development of egg and larval stages under changing temperatures was compared with values predicted from constant temperature experiments. The rate of development of eggs to hatching was significantly accelerated under regimes of both sudden and gradual temperature changes. The effect of fluctuating temperatures on larval development was less consistent; both acceleration and retardation effects were recorded. Frog tadpoles (Rana temporaria) were experimentally infected with O. filiformis; early parasitic development proceeded significantly faster at room temperature than at 9–10°C.

The life history and development ofAmplicaecum robertsi, an ascaridoid nematode of the carpet python (Morelia spilotes variegatus). I. Morphology and functional significance of larval stages

Parasitology ◽  
1963 ◽  
Vol 53 (1-2) ◽  
pp. 7-38 ◽  
Author(s):  
J. F. A. Sprent
Keyword(s):  
Functional Significance ◽  
Structural Changes ◽  
Adult Stage ◽  
Reproductive Organs ◽  
Fourth Stage ◽  
Laboratory Rats ◽  
Larval Stages ◽  
Second Stage ◽  
The Third ◽  
Third Stage

The development ofAmplicaecum robertsihas been followed from the egg to the adult stage using laboratory mice and rats as intermediate hosts. The eggs were found to be resistant to desiccation and would develop under water; they were infective to mice after culturing for 18 days after removal from the uterus.Completion of the first moult occurred after hatching of the eggs in the intestine. Within 6 hr. of infection second-stage larvae had reached the liver. They also appeared in the lungs and carcass, but after 2 days were mostly confined to the liver.At 5–7 days after infection larvae underwent a period of lethargy followed by the second moult and the third-stage larvae commenced a period of growth reaching a length of 79 mm. at 28 weeks after infection in the liver of mice. In rats the growth of the larvae was slower for the first 2 months, but eventually they reached more or less the same proportions as in mice. The intestinal caecum appeared at a length of 3–4 mm., but there was no development of the reproductive organs throughout the third stage and no evidence of the third moult in rodents.Fifty carpet snakes were autopsied and searched for larvae and adults ofA. robertsi; in two snakes third-stage larvae were found in the aorta; in one snake the third moult was observed in the wall of the stomach and oesophagus; in three snakes the fourth moult was observed in the wall of the stomach; in twenty-six snakes adults were found.Experimental infection of laboratory-reared carpet snakes showed that infection with embryonated eggs resulted in second-stage larvae in the tissues which did not develop further. Infection with third-stage larvae, resulted in two distinct migratory patterns depending upon the maturity of the larvae administered. Larvae from the liver of laboratory rats which had been infected less than 12 weeks previously, migrated to various tissues, especially the aorta, of the snake, where they remained coiled in cysts filled with clotted blood for periods up to 112 days. Growth occurred within these cysts, but no evidence of moulting was observed. In contrast, larvae from the liver of laboratory rats infected 12 weeks or more previously, and from mice infected for 8 weeks or more, underwent the third moult in the wall of the oesophagus and stomach of the snake.With the onset of the fourth stage, the development of the reproductive organs became evident and continued during the fourth stage. It appeared that the fourth stage may occur in two phases, possibly depending on the size of the third-stage larva at the time of ingestion. Some experimental infections indicated that third-stage larvae may give rise to attached fourth stage larvae, probably capable of active growth. Other observations indicated that fourth-stage larvae may remain encapsulated in the wall of the stomach or oesophagus until sex differentiation is completed, after which the fourth moult occurs and the adult parasite emerges, leaving two sheaths of the same length within the capsule.The functional significance of each of the larval stages is discussed and it was concluded:—that the first-stage larva is one of tissue differentiation, whereby development proceeds to the infective stage; that the second stage represents a migratory phase without structural changes; that the third stage represents a growth phase, characterized by considerable increase in size, but without further radical changes in differentiation.In contrast, the fourth stage is characterized by absence of growth, inability to migrate, and by marked structural changes in the reproductive organs, whereby the sexes are differentiated. Evidently this development may take place while the fourth stage is attached to the wall of the stomach or oesophagus, or while the larva remains in the capsule in a state of quiescence.The fourth moult may occur in the attached state, but usually occurs within the capsule. After it is completed, the adult may remain for an indefinite period within the capsule with the two sheaths of the third and fourth stage. The emergence of the adult worms may be influenced by the arrival of food in the stomach. Once this phase is initiated, both growth and reproductive activity ensue during the adult stage.This work was financed by a research grant from the University of Queensland. The writer wishes to acknowledge the valuable assistance of Miss Ann Pritchard.

Experimental transmission of Pharurus pallasii (Nematoda: Metastrongyloidea), a lungworm of the cranial sinuses of the beluga whale (Delphinapterus leucas), to fish

2003 ◽  
Vol 81 (3) ◽  
pp. 364-370 ◽  
Author(s):  
Magali Houde ◽  
Lena N Measures ◽  
Jean Huot
Keyword(s):  
Gravid Female ◽  
Final Host ◽  
Intestinal Wall ◽  
Beluga Whale ◽  
Delphinapterus Leucas ◽  
Intermediate Hosts ◽  
Post Exposure ◽  
Larval Stages ◽  
Beluga Whale Delphinapterus Leucas ◽  
Paratenic Hosts

Transmission of lungworms (Metastrongyloidea: Pseudaliidae) in the marine environment has been poorly studied. This experimental study is the first conducted on a pseudaliid, Pharurus pallasii, a lungworm of the cranial sinuses of the beluga whale (Delphinapterus leucas). First-stage larvae removed from uteri of gravid female P. pallasii from a freshly dead beluga were experimentally exposed to various marine organisms (fish, crustaceans, molluscs). First-stage larvae failed to develop in experimentally exposed invertebrates. The first moult occurred in the intestinal wall of American plaice (Hippoglossoides platessoides) and Arctic sculpins (Myoxocephalus scorpioides) 45 and 78 days post exposure, respectively. The third larval stage, which is infectious to the final host, was not observed in fish during the 14 months of the experiment. No cellular inflammatory reaction to or encapsulation of larvae was observed in histological sections of the intestinal wall of American plaice 268 days post exposure. Survival and development of P. pallasii larvae to the second stage in fish suggest that fish are likely suitable intermediate hosts in the life cycle of P. pallasii. Invertebrates may still play a role as transport (paratenic) hosts. The morphology of the first and second larval stages of P. pallasii is described for the first time.

Dirofilaria aethiops Webber, 1955, a filarial parasite of monkeys III. The larval development in mosquitoes

Parasitology ◽  
1955 ◽  
Vol 45 (3-4) ◽  
pp. 388-400 ◽  
Author(s):  
Winfrith A. F. Webber
Keyword(s):  
Relative Humidity ◽  
Connective Tissue ◽  
Death Rate ◽  
Morphological Development ◽  
Larval Stages ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Pass Through ◽  
Very High

1. A description is given of the morphological development of the larval stages of Dirofilaria aethiops in the mosquito Aëdes aegypti.2. The first-stage larvae migrate from the stomach to the connective tissue in all parts of the mosquito body, where they pass through the inactive ‘sausage’ stages. At 26° C. and 80% relative humidity the first moult takes place about the twelfth day of development and the second moult about the sixteenth day. The third-stage larvae migrate towards the proboscis where they can be found after 18–20 days.3. The number of microfilariae ingested by the mosquito is approximately equal to the number which would be expected from the numbers in the blood of the monkey and the volume of the blood meal. The death rate of the larvae in the mosquitoes is very high for the first 2 days, but less severe later. Approximately 1% of the ingested microfilariae survive 20 days; at this time two-thirds of the surviving larvae have reached the third stage.4. Comparison of D. aethiops with other filariae shows that first-stage larvae of different species can often be distinguished by the structure of the tail, which is the same as that of the microfilaria. Second-stage larvae are similar to each other in morphology but develop in characteristic sites in the host. Third-stage larvae differ from each other in the cephalic and caudal papillae.

Sign in / Sign up

Export Citation Format

Share Document