Distribution of Oesophagostomum columbianum larvae along the alimentary tract of the sheep

1966 ◽  
Vol 17 (5) ◽  
pp. 765 ◽  
Author(s):  
C Dobson
Keyword(s):  
Small Intestine ◽  
Alimentary Tract ◽  
Environmental Changes ◽  
Body Cavity ◽  
The Body ◽  
Linear Distribution ◽  
A Value ◽  
Oesophagostomum Columbianum ◽  
Third Stage ◽  
Two Peaks

Linear distribution of the third-stage larvae of O. columbianum along the alimentary tract, and ectopic distribution within the organs of the body cavity, were investigated in sheep which were given first, second, and third infestations with 5000 larvae. Two types of nodule were recognized: (1) small gritty lesions, which predominated in the small intestine; (2) caseous nodules, mostly found in the large intestines. Linear distribution of the larvae was characterized by two peaks in numbers along the small intestine, the first immediately posterior to the common bile duct and the second at the ileocaecal valve. The origin of these peaks is discussed in relation to the exsheathment and subsequent behaviour of third-stage larvae and the flow of ingesta along the gut. Three peaks in larvae numbers were recognized in the large intestine; these are discussed in relation to the movements of ingesta. After second and third infestations the numbers of caseous nodules increased and those of ectopic migrations decreased. Also a third peak in the numbers of larvae invading the wall of the small intestine occurred at the beginning of the ileum. This is discussed in relation to the immunity reactions of the host. Of O. columbianum larvae, 75% were found to exsheath in the rumen after 12 hr; pH alone had little effect on exsheathment, except at a value of 6.5, which is equivalent to the pH of the ruminal contents when 10% of the larvae exsheathed after 8 hr. The effects of fresh bile on larval activity was also studied. These results are discussed in relation to the linear distribution of the larvae. It is suggested that after larvae have exsheathed, they respond specifically to environmental change by penetrating the gut wall. When the larvae penetrate into the body cavity, environmental changes are absent and the resultant larval migrations are completely random. It is also suggested that the final area in which the adult worm will settle depends on the part of the gut in which the larvae exsheathed and the area of the gut wall which the activated larvae penetrated. The distribution of caseous nodules is discussed in relation to the host specificity of O. columbianum.

scholarly journals The occurrence of Contracaecum sp. larvae (Nematoda : Anisakidae) in the catfishClarias gariepinus (Burchell) from Lake Chivero, Zimbabwe

2004 ◽  
Vol 71 (1) ◽  
Author(s):  
M. Barson
Keyword(s):  
Significant Relationship ◽  
Condition Factor ◽  
Clarias Gariepinus ◽  
Parasite Prevalence ◽  
Body Cavity ◽  
The Body ◽  
Nematode Parasites ◽  
Significant Difference ◽  
Third Stage ◽  
Males And Females

Clarias gariepinus were collected from Lake Chivero, Zimbabwe, and examined for nematode parasites from November 2000 to May 2002. Of the 202 specimens collected, 42.6 % were infected with third-stage larvae of Contracaecum sp. in the body cavity. The intensity of the infection was 1-7 worms per fish (mean intensity = 2.2). Seasonal variation in the prevalence of the parasite was not obvious and there was no significant difference in the prevalence of infection between males and females (c2 = 2.228; P > 0.05). No significant relationship between host size and prevalence was established. There was also no significant relationship between intensity and the body condition factor (r = 0.11; P > 0.05). The low parasite prevalence may have been caused by the disruption of the infection cycle since piscivorous birds, which are the final hosts of the parasite, do not feed on C. gariepinus in Lake Chivero.

scholarly journals Occurrence of nematodes of the genus Anisakis in Mediterranean and Atlantic fish marketed in Sardinia

2017 ◽  
Vol 6 (1) ◽  
Author(s):  
Daniele Casti ◽  
Christian Scarano ◽  
Maria Cristina Piras ◽  
Paolo Merella ◽  
Sonia Muglia ◽  
...  
Keyword(s):  
Visual Inspection ◽  
Sensu Stricto ◽  
Body Cavity ◽  
The Body ◽  
Type I ◽  
Merluccius Merluccius ◽  
Commercial Fish ◽  
Scomber Colias ◽  
Third Stage ◽  
The Mean

Anisakiasis is a gastrointestinal fishborne zoonosis caused by the ingestion of third stage larvae of the genus <em>Anisakis</em>. Between January and December 2013, 1112 specimens of four commercial fish species (<em>Engraulis encrasicolus, Merluccius merluccius, Scomber colias</em> and <em>Trachurus mediterraneus</em>) marketed in Sardinia (Italy) were examined for <em>Anisakis</em> sp. The overall prevalence of <em>Anisakis</em> spp larvae was 39.9%, all morphologically identified as Type I. <em>Scomber colias</em> showed the highest prevalence (100%), followed by <em>M. merluccius</em> (Atlantic 91.0%, Mediterranean 71.2%), <em>T. mediterraneus</em> (32.7%) and <em>E. encrasicolus</em> (25.9%). All the larvae found in Mediterranean hosts were genetically identified as <em>Anisakis pegreffii</em>, whereas 90.0% of the larvae found in the Atlantic <em>M. merluccius</em> belonged to <em>Anisakis simplex sensu stricto</em> and 10.0% to <em>A. pegreffii</em>. The mean abundance of <em>Anisakis</em> sp. larvae was positively correlated with fish size in <em>E. encrasicolus</em>, Atlantic <em>M. merluccius</em> and local <em>M. merluccius</em>. The prevalence of infection was greater in the body cavity (37.9%) than in the edible muscle (9.4%). However, 1.8% of the examined fish were infected exclusively in the muscle. Therefore, the risk associated to the consumption of raw or undercooked fishery products poses the need of measures such as visual inspection and preventive treatments to guarantee consumers’ health.

Fasciola hepatica: a technique for the study of gut penetration by juvenile flukes

Parasitology ◽  
1981 ◽  
Vol 83 (2) ◽  
pp. 249-252 ◽  
Author(s):  
D. J. Burden ◽  
A. P. Bland ◽  
D. L. Hughes ◽  
N. C. Hammet
Keyword(s):  
Electron Microscopy ◽  
Small Intestine ◽  
Fasciola Hepatica ◽  
Body Cavity ◽  
The Body ◽  
Ultrathin Sections ◽  
Resistance To Infection ◽  
Electron Microscopes

SUMMARYA method using light and electron microscopes is described which is suitable for the examination of gut penetration by juvenile Fasciola hepatica. It involved the ligation of small sections of the small intestine of rats and the introduction of artificially excysted flukes into these gut loops. By restricting the area of infection in this way it was possible to either recover flukes from the gut lumen or to prepare ultrathin sections for electron microscopy of flukes penetrating the gut wall. In addition, flukes were recovered from the body cavity at various times after preparation of loops in resistant and naive rats. It was found that more flukes reached the body cavity in naive rats than in resistant rats, demonstrating a resistance to infection in the gut loops of sensitized rats.

The Development of Gastric Tumours in Drosophila Larvae

Development ◽  
1957 ◽  
Vol 5 (2) ◽  
pp. 143-152
Author(s):  
H. H. El Shatoury ◽  
C. H. Waddington
Keyword(s):  
Salivary Glands ◽  
Alimentary Tract ◽  
Normal Development ◽  
Body Cavity ◽  
The Body ◽  
Wild Type ◽  
Lymph Glands ◽  
Drosophila Larvae ◽  
Hind Gut ◽  
Formation Of Groups

It has been shown that in the normal development of wild-type Drosophila larvae, a process of hypertrophy or proliferation leading to the formation of groups of non-nucleated cellular masses occurs in the mid-gut (stomach) and at the imaginal primordia of the hind-gut and the salivary glands in both the first and second instars (Shatoury & Waddington, 1957b). The process takes place just at the time when the lymph glands hypertrophy and release cells into the body-cavity and the excessive growths of the organs of the alimentary tract regress and are resorbed as soon as the lymph glands become regenerated. The appearances strongly suggest that there is a causal connexion between the proliferation of the lymph glands cells and the hypertrophy which occurs in the gut and salivary glands.

Acanthocephalan infection of inshore fish in two fjords at South Georgia

1992 ◽  
Vol 4 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Krzysztof Zdzitowiecki ◽  
Martin G. White
Keyword(s):  
Dominant Species ◽  
Alimentary Tract ◽  
Body Cavity ◽  
The Body ◽  
South Shetland Islands ◽  
Shetland Islands ◽  
South Georgia ◽  
Species Association ◽  
Fur Seal ◽  
Seal Population

An examination of 111 fish of eight species, including 92 immature Notothenia rossii Richardson revealed nine acanthocephalan species, including four Echinorhynchida occurring in the alimentary tract and five Polymorphida in the body cavity. Echinorhynchida were much more numerous (87% specimens of 4855 collected), especially Metacanthocephalus johnstoni Zdzitowiecki (the dominant species) and Aspersentis megarhynchus (Linstow). The Polymorphida parasites of seals (three species) were more abundant than species parasitic in birds (two species). Association of most of species, (except Corynosoma bullosum (Linstow) and Echinorhynchus spp.), with the inshore (fjord) environment was confirmed. The species diversity, prevalence and density of infection increased with the size of immature N. rossii. Differences in acanthocephalan occurrence and changes with time are related to differences in host distribution and abundance. For example, the occurrence of C. arctocephali in N. rossii at South Georgia is related to the increase of the fur seal population. A list of acanthocephalans in fish at South Georgia and the South Shetland Islands (14 species in total) is included.

Experimental Infection of Rainbow Trout, Oncorhynchus mykiss, with Contracaecum osculatum (Rudolphi, 1802) and Pseudoterranova decipiens (Krabbe, 1878) (Nematoda; Ascaridoidea)

1990 ◽  
Vol 47 (12) ◽  
pp. 2293-2296 ◽  
Author(s):  
J. W. Smith ◽  
A. E. Elarifi ◽  
R. Wootten ◽  
A. W. Pike ◽  
M. D. B. Burt
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Body Cavity ◽  
The Body ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Pseudoterranova Decipiens ◽  
Third Stage ◽  
Contracaecum Osculatum ◽  
Merlangius Merlangus ◽  
Northern North Sea

The fate of freshly hatched larvae of the marine ascaridoid nematodes Contracaecum osculatum and Pseudoterranova decipiens (from grey seals, Halichoerus grypus, from Scotland and the Canadian Atlantic) was investigated following oral or intraperitoneal introduction into rainbow trout, Oncorhynchus mykiss, maintained at 7–13 °C in fresh water. Neither species appeared to survive for long in the trout alimentary tract following oral introduction; a few larvae were found alive after 2 d but none after 21 d. intraperitoneally, P. decipiens did not survive beyond 21 d, but some C. osculatum exsheathed and developed over several months to lengths over 13 mm, and morphologically and morphometrically resembled third-stage larvae from naturally infected whiting, Merlangius merlangus, from the northern North Sea; no moult was detected. Thus, freshly hatched free-living larvae of C. osculatum are able to develop directly to the third stage in the body cavity of a fish without earlier passage through a crustacean or other invertebrate host.

scholarly journals Morphological and Molecular Characteristics of Anisakis typica Larvae in Two Species of Threadfin Bream, Nemipterus hexodon and N. japonicus, from the Gulf of Thailand

2020 ◽  
Vol 58 (1) ◽  
pp. 15-25
Author(s):  
Rattanachai Tunya ◽  
Chalobol Wongsawad ◽  
Pheravut Wongsawad ◽  
Jong-Yil Chai
Keyword(s):  
Abdominal Cavity ◽  
Body Cavity ◽  
The Body ◽  
Molecular Characteristics ◽  
Cylindrical Shape ◽  
Gulf Of Thailand ◽  
Third Stage ◽  
The Gulf Of Thailand ◽  
Almost All ◽  
Anisakid Larvae

The third stage larvae (L3) of <i>Anisakis typica</i> were detected in 2 species of threadfin bream, <i>Nemipterus hexodon</i> and <i>N. japonicus</i>, from the Gulf of Thailand, and were morphologically and molecularly characterized. Total 100 threadfin breams, 50 <i>Nemipterus hexodon</i> and 50 <i>N. japonicus</i>, were examined with naked eyes after the opening of abdominal cavity with scissors. Almost all infected larvae remained alive and active even the fish were transported for 1-2 days. Anisakid larvae were exclusively distributed in the body cavity and rarely in the liver. The prevalence of <i>A. typica</i> L3 were 68.0% and 60.0% in <i>N. hexodon</i> and <i>N. japonicus</i> and their infection intensities were 3.5 and 4.2 per fish infected each. Morphological and morphometric analysis were performed by viewing specimens under both a light microscope and a scanning electron microscope. Interestingly, the protruded mucron of <i>Anisakis typica</i> under SEM showed a distinct cylindrical shape that differed from the cone shape of <i>A. simplex</i>. The protruded mucron could be used to identify <i>A. typica</i> L3 larvae in the future. A comparison of the ITS1-5.8S-ITS2 rDNA nucleotide sequences of these species revealed high blast scores with <i>A. typica</i>. Conclusively, it was confirmed that <i>A. typica</i> L3 are prevalent in threadfin breams from the Gulf of Thailand, and their morphological and molecular characters are something different from those of other anisakid larvae, including A. simplex and <i>A. pegreffii</i>.

scholarly journals Digestive plasticity of the small intestine and the fermentative hindgut in a marsupial herbivore, the tammar wallaby (Macropus eugenii)

2006 ◽  
Vol 54 (4) ◽  
pp. 287 ◽  
Author(s):  
Adam J. Munn ◽  
Peter Banks ◽  
Ian D. Hume
Keyword(s):  
Small Intestine ◽  
Body Mass ◽  
Alimentary Tract ◽  
Nutritional Ecology ◽  
Tammar Wallaby ◽  
Proximal Colon ◽  
The Body ◽  
Macropus Eugenii ◽  
Diet Versus ◽  
Pelleted Diet

We investigated the effects of a ground, pelleted diet versus natural forage on the gross morphology of the gastrointestinal tract of a medium-sized (5–7 kg body mass) macropodid marsupial, the tammar wallaby (Macropus eugenii). The empty wet mass (g) of the small intestine of tammar wallabies maintained on a pelleted diet for 6 weeks was 22% greater than that of animals maintained on natural forage, once body mass was taken into account by ANCOVA. Similarly, the body-mass-adjusted length of the tammar wallaby caecum and proximal colon combined was 25% longer in animals maintained on the pelleted diet compared with those maintained on forage. Our data suggest that food particle size may be directly involved in controlling the size of the post-gastric alimentary tract in tammar wallabies, and thus in their diet choice and nutritional ecology. Notably, this is the first study that links phenotypic plasticity of the gut directly to diet in a marsupial and we conclude that the tammar wallaby is an excellent model for exploring the causes and consequences of digestive plasticity in macropodid marsupials.

Studies on the excystment of trematode metacercariae in vivo

1974 ◽  
Vol 48 (1) ◽  
pp. 85-91 ◽  
Author(s):  
M. F. A. Asanji ◽  
M. O. Williams
Keyword(s):  
Small Intestine ◽  
Definitive Host ◽  
Fasciola Hepatica ◽  
Clonorchis Sinensis ◽  
Body Cavity ◽  
The Body ◽  
Parorchis Acanthus ◽  
Migratory Route ◽  
Ph Range

AbstractMetacercariae of two species of trematode (Clinostomum tilapiae, Postodiplostomum nanum) excysted in the stomach of birds, while those of three species (Parorchis acanthus, Posthodiplostomum sp., Postliodiplostomoides leonensis) excysted in the duodenum. Differences were related to the structure of the cyst wall. All could excyst in birds which were not the definitive host and the speed of excystment depended on the speed of movement of food in the gut. All, except P. acanthus, also excysted in the body cavity of the mouse.There have been few previous reports on the site of excystment of metacercarial cysts in vivo and most indicate that the duodenum is the site for most species studied, e.g. Clonorchis sinensis (Faust and Khaw, 1927), Parorchis avitus (Stunkard and Cable, 1932), Cryptocotyle lingua (Smyth, 1962) and Fasciola hepatica (Smyth, 1966). In their study of the migratory route of Paragonimus westermani in rats, cats and guinea-pigs Yokogawa et al. (1962) found that excystment occurred in the small intestine where the pH range was 5.0–6.0. Also, although the site of excystment has been established for some species, very little quantitative work has been reported about the percentage excystment in vivo and results of work on these lines is reported in this paper.

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