Formation of the gut in the first two naupliar stages of Acartia clausi and Hemidiaptomus roubaui (Copepoda, Calanoida): comparative structural and ultrastructural aspects

2002 ◽  
Vol 80 (2) ◽  
pp. 232-244 ◽  
Author(s):  
A Baud ◽  
R -M Barthélémy ◽  
S Nival ◽  
M Brunet
Keyword(s):  
Epithelial Cells ◽  
Digestive Tract ◽  
Digestive System ◽  
Larval Stages ◽  
Acartia Clausi ◽  
The Future ◽  
Endodermal Cells ◽  
Structure And Ultrastructure

In this study, the structure and ultrastructure of the digestive system are compared in the early larval stages (nauplii I and II) of two copepod calanoid species, Acartia clausi Giesbrecht, 1889 and Hemidiaptomus roubaui Richard, 1888. The nauplii I of both species have no functional digestive tract, which is represented initially only by a blind esophageal slit and yolky endodermal cells, which fill the most part of the naupliar body, whereas at the nauplius II stage the differentiated digestive tract becomes functional. The resorption cavity corresponding to the future midgut is progressively formed in the endodermal mass during the premolt phase; it is surrounded by differentiating epithelial cells. In the ecdysial phase the foregut has associated labral glands, the midgut young R-, B-, and R'-cells of epithelium, and there is a short open hindgut.

The Nematodes That Cause Anisakiasis1,2

1975 ◽  
Vol 38 (12) ◽  
pp. 774-782 ◽  
Author(s):  
BETTY JUNE MYERS
Keyword(s):  
Digestive Tract ◽  
Cross Sections ◽  
Excretory Pore ◽  
Digestive System ◽  
Diagnostic Value ◽  
Morphological Features ◽  
Numerous Species ◽  
Larval Stages ◽  
Tissue Sections ◽  
Fish Hosts

Anisakine nematodes responsible for human anisakiasis have been recognized in fish hosts for over a decade. They are larval stages, relatively simple in form, and lack many morphological features used for identification of the adults (e.g., cephalic structures, spicules, etc.). However, these immature helminths can be sorted into larval types on the basis of the anterior digestive tract formation and the position of the excretory pore. Problems in identfying larvae, even as to type, are often encountered in tissue sections that may not show those anterior regions containing features of the digestive system which are diagnostic for type sorting. Hence, it is necessary to reconsider the diagnostic value of lateral chords, muscle cells, etc., that are visible in all cross-sections. Fish which are eaten by the human consumer also contain larval stages of other roundworms (nematodes) than those responsible for human anisakiasis, as well as numerous species of adult nematodes.

The Development and Growth of Ciona

1947 ◽  
Vol 26 (4) ◽  
pp. 616-625 ◽  
Author(s):  
N. J. Berrill
Keyword(s):  
Nervous System ◽  
Digestive System ◽  
Ciona Intestinalis ◽  
Growth Cycle ◽  
General Interest ◽  
Botryllus Schlosseri ◽  
Developmental Studies ◽  
Larval Stages ◽  
Artificial Fertilization ◽  
Sexually Mature

Ciona intestinalis (L.) is probably the most cosmopolitan species of ascidians and has long been of general interest. The adult morphology has been well described in monographic form by Roule (1884), the physiology of the heart and circulation by Heine (1902), Enriques (1904) and Wolf (1932), of the nervous system by Magnus (1902), Hecht (1918, 1926), Cate (1928), Haffner (1933), and Bacq & Florkin (1935), and of the digestive system by Yonge (1925). Developmental studies include that of the early embryology by Conklin (1905), problems of fertilization by Morgan (1945) and Damas (1899,1900). In no work, however, has there been a presentation of the entire Ciona organism from the tadpole stage through the critical post-larval stages to the young cionid ascidian. The present account portrays this period of development, together with a discussion of some significant but relatively obscure aspects of adult structure.Eggs and theRearing ofCiona intestinalisWhile ascidians in general are difficult to rear to maturity under laboratory conditions, Ciona is relatively easy, and together with Botryllus schlosseri (Pallas) and Diplosoma gelatinosum (M.-Edw.) is liable to appear more or less spontaneously in large aquaria into which tadpoles may have been brought. Artificial fertilization is readily accomplished, and at almost any time of the year, since Ciona is sexually mature above a certain size and reproduction is seasonal only to the extent of the rhythm of the growth cycle. Normally eggs are set free spontaneously at dawn, although individuals kept in the laboratory may accumulate eggs and the oviduct become swollen.

scholarly journals Morphohistology of the Digestive Tract of the Damsel FishStegastes fuscus(Osteichthyes: Pomacentridae)

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Bhaskara Canan ◽  
Wallace Silva do Nascimento ◽  
Naisandra Bezerra da Silva ◽  
Sathyabama Chellappa
Keyword(s):  
Digestive Tract ◽  
Transition Region ◽  
Digestive System ◽  
Feeding Habits ◽  
Northeastern Brazil ◽  
Muscular Layer ◽  
Pyloric Caeca ◽  
Anterior Intestine ◽  
The Mean ◽  
Tidal Pools

This study investigated the morphohistology of the digestive tract and the mean intestinal coefficient of the damsel fishStegastes fuscuscaptured from the tidal pools of Northeastern Brazil. The wall of the digestive tract ofS. fuscusis composed of the tunica mucosa, tunica muscularis, and tunica serosa. The esophagus is short with sphincter and thick distensible wall with longitudinally folded mucosa. Mucous glands are predominant, and the muscular layer of the esophagus presented striated fibers all along its extension. The transition region close to the stomach shows plain and striated muscular fibers. Between the stomach and intestine, there are three pyloric caeca. The intestine is long and thin with four folds around the stomach. The anterior intestine presents folds similar to those of pyloric caeca. The estimated mean intestinal coefficient and characteristics of the digestive system ofS. fuscuspresent morphological adequacy for both herbivorous and omnivorous feeding habits.

The enteric nervous system of echinoderms: unexpected complexity revealed by neurochemical analysis

2001 ◽  
Vol 204 (5) ◽  
pp. 865-873
Author(s):  
J.E. Garcia-Arraras ◽  
M. Rojas-Soto ◽  
L.B. Jimenez ◽  
L. Diaz-Miranda
Keyword(s):  
Nervous System ◽  
Enteric Nervous System ◽  
Digestive Tract ◽  
Radial Nerve ◽  
Digestive System ◽  
Nerve Ring ◽  
Point Of View ◽  
Distinct Component ◽  
Future Studies ◽  
Neurochemical Analysis

Echinoderms are one of the most important groups of metazoans from the point of view of evolution, ecology and abundance. Nevertheless, their nervous system has been little studied. Particularly unexplored have been the components of the nervous system that lie outside the ectoneural and hyponeural divisions of the main nerve ring and radial nerve cords. We have gathered information on the nervous components of the digestive tract of echinoderms and demonstrate an unexpected level of complexity in terms of neurons, nerve plexi, their location and neurochemistry. The nervous elements within the digestive system consist of a distinct component of the echinoderm nervous system, termed the enteric nervous system. However, the association between the enteric nervous system and the ectoneural and hyponeural components of the nervous system is not well established. Our findings also emphasize the importance of the large lacunae in the neurobiology of echinoderms, a feature that should be addressed in future studies.

scholarly journals Occurrence of Tetracampos ciliotheca and Proteocephalus glanduligerus in Clarias gariepinus (Burchell, 1822) collected from the Vaal Dam, South Africa

2013 ◽  
Vol 80 (1) ◽  
Author(s):  
Grace Madanire-Moyo ◽  
Annemariè Avenant-Oldewage
Keyword(s):  
South Africa ◽  
Digestive Tract ◽  
Standard Length ◽  
Feeding Habits ◽  
Clarias Gariepinus ◽  
Male And Female ◽  
Mean Intensity ◽  
Gill Nets ◽  
Larval Stages ◽  
Vaal Dam

Cestodes are parasitic flatworms that live in the digestive tract of vertebrates as adults and often in the liver, muscle, haemocoel, mesentery and brain of various animals as larval stages. To identify the cestodes infecting Clarias gariepinus Burchell, 1822 (sharptooth catfish) in the Vaal Dam, a total of 45 host specimens were collected with the aid of gill nets between October 2011, January and April 2012. The fish were sacrificed and examined for cestode parasites. Two adult cestodes, Tetracampos ciliotheca Wedl, 1861 (prevalence 86.7%, mean intensity = 15, n = 45) and Proteocephalus glanduligerus (Janicki, 1928) (prevalence 51.1%, mean intensity = 5, n = 45) were found in the intestines of the catfish. Both T. ciliotheca and P. glanduligerus are new locality records. There were statistically insignificant differences in the infection of the male and female C. gariepinu. Fish with standard length ranging from 40 cm – 54 cm (≥ 3 years) had the highest prevalence and mean intensity while those ranging from 10 cm – 24 cm (< 1 year) had the lowest prevalence and mean intensity for both cestodes. The study highlights the importance of changing feeding habits of C. gariepinus with age on the prevalence and mean intensity of the two gastrointestinal cestode parasites.

scholarly journals ABO histo-blood groups and Rh systems in relation to malignant tumors of the digestive tract in Bosnia and Herzegovina

2008 ◽  
Vol 60 (4) ◽  
pp. 593-599 ◽  
Author(s):  
Snezana Jovanovic-Cupic ◽  
Gorana Stamenkovic ◽  
Jelena Blagojevic ◽  
N. Vanis ◽  
B. Stanojevic ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Digestive Tract ◽  
Digestive System ◽  
Malignant Tumors ◽  
Blood Groups ◽  
Liver Carcinoma ◽  
Abo Blood Groups ◽  
Rhesus Factor ◽  
Clinical Center ◽  
Group B

The distribution of ABO blood groups and the Rhesus factor was analyzed in 279 patients who suffered from malignant tumors of the digestive system. Patients were registered retrospectively in the Gastroenterohepatology Clinic, Clinical Center, University of Sarajevo over a discontinuous period of 88 months. From the results obtained, it was concluded that: (a) men became ill from gastric cancer significantly more frequently than women; (b) the frequency of liver carcinoma was three times higher than the global frequency and the frequency neighboring ethnic groups; and (c) patients with blood group B and patients with RhD(-) exhibited a significantly higher proportion of disease.

THE GROSS AND MICROSCOPIC ANATOMY OF THE DIGESTIVE TRACT OF THE OYSTER CRASSOSTREA VIRGINICA (GMELIN)

1957 ◽  
Vol 35 (3) ◽  
pp. 325-347 ◽  
Author(s):  
Barbara L. Shaw ◽  
Helen I. Battle
Keyword(s):  
Epithelial Cells ◽  
Digestive Tract ◽  
Crassostrea Virginica ◽  
Atlantic Coast ◽  
Dorsal Surface ◽  
Adductor Muscle ◽  
Posterior Chamber ◽  
Microscopic Anatomy ◽  
The North ◽  
Cytoplasmic Processes

The gross and microscopic anatomy of the digestive tract of Crassostrea virginica (Gmelin), the common oyster of commerce of the North Atlantic Coast, is described. The dorsoventrally compressed mouth bounded by two pairs of labial palps leads into a crescentic oesophagus, thence to the anterior chamber of the stomach from which a complex caecum extends into anteriorly and posteriorly directed spiral appendices. The posterior chamber of the stomach bears a chondroid gastric shield and leads into an elongated chamber which is incompletely divided by two typhlosoles into a style-sac and mid-gut. The intestine is divisible into ascending, median, and descending limbs, the latter merging into the rectum which terminates on the dorsal surface of the adductor muscle. Extensively branched tubular digestive diverticula exit from the stomach by a series of ducts along the margin of the caecum and the posterior stomach. The complete digestive tract is lined by a simple columnar epithelium which is ciliated throughout with the exception of the upper lip or fused external palps, the lower side of the gastric shield in the posterior stomach, and the tubules of the digestive diverticula. Mucous secreting and eosinophilic epithelial cells occur in varying numbers along the course of the tract. Phagocytes are present between the lining epithelial cells, among the peripheral collagenous and muscle fibers, as well as in the lumen of the tract. The gastric shield is shown to be intimately attached to the underlying epithelium by a central clip as well as by minute cytoplasmic processes. The anatomical relationships are compared with various lamellibranchs including the Chilean oyster, Ostrea chilensis Philippi; the European oyster, Ostrea edulis L.; and the Portuguese oyster, Gryphea angulata Lamarck.

Differentiation of the yolk-sac endoderm under the influence of the digestive-tract mesenchyme

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 277-289
Author(s):  
Tohru Masui
Keyword(s):  
Digestive Tract ◽  
Goblet Cells ◽  
Yolk Sac ◽  
Intestinal Type ◽  
Area Vasculosa ◽  
Self Differentiation ◽  
Parenchymal Cells ◽  
Endodermal Cells ◽  
Area Pellucida

To reveal differentiation potency of yolk-sac endoderm, this tissue from quail embryos was cultured alone or in association with digestive-tract mesenchymes of chick embryos. When yolk-sac endoderm was cultured alone in vitro, the endoderm of the area vitellina differentiated into the yolk-sac parenchyma, but the endoderm of the extraembryonic area pellucida (EEAP) failed to differentiate into yolk-sac parenchyma, and the endoderm of the area vasculosa became necrotic. When endoderm of the area vitellina was cultured in association with digestive-tract mesenchymes, all the endodermal cells developed into yolk-sac parenchymal cells after two days. Later, basophilic cells appeared among them, and differentiated into both mesenchymespecific epithelia and intestinal-type epithelium with a striated border, and villi were also formed. Goblet cells appeared in all types of recombinations. The endoderm of the EEAP cultured with digestive-tract mesenchymes gave similar results to that of the area vitellina. In contrast, endoderm of the area vasculosa, when cultured with digestive-tract mesenchymes,became necrotic. The present investigation demonstrated that the endoderms of the area vitellina and of the EEAP differ in self-differentiation potency, and that their developmental fates can be modified by the influence of digestive-tract mesenchymes. These endoderms can differentiate into the mesenchyme-specific epithelia, though they often differentiate also into the intestinal-type epithelium.

scholarly journals Association of the Insulinemic Potential of Diet and Lifestyle With Risk of Digestive System Cancers in Men and Women

2018 ◽  
Vol 2 (4) ◽  
Author(s):  
Weike Wang ◽  
Teresa T Fung ◽  
Molin Wang ◽  
Stephanie A Smith-Warner ◽  
Edward L Giovannucci ◽  
...  
Keyword(s):  
Digestive Tract ◽  
Digestive System ◽  
Cox Regression ◽  
Health Study ◽  
Men And Women ◽  
Dietary Index ◽  
Hazard Ratios ◽  
Incident Cancer ◽  
Men Health ◽  
Diet And Lifestyle

Abstract Background We examined the role of the insulinemic potential of diet and lifestyle in the development of cancers of the digestive system, using two plasma C-peptide-based indices: the empirical dietary index for hyperinsulinemia (EDIH) and empirical lifestyle index for hyperinsulinemia (ELIH). Methods We used Cox regression to analyze data on 45 816 men (Health Professionals Follow-up Study, 1986–2012) and 74 191 women (Nurses’ Health Study, 1984–2012) to examine associations between EDIH and ELIH scores and digestive system cancers. We computed the diet-only score (EDIH) from food-frequency questionnaires administered every 4 years. The lifestyle score (ELIH) included diet, body mass index, and physical activity. Outcomes included incident cancer of the digestive system (mouth, throat, esophagus, stomach, small intestine, and colorectum) and its accessory organs (pancreas, gallbladder, and liver). P values were two-sided. Results We found direct associations between higher insulinemic potential of diet or lifestyle and risk of developing digestive system cancers in both men and women. The pooled multivariable hazard ratios (HRs) for participants comparing the highest to lowest EDIH quintile were: HR = 1.27, 95% confidence interval (CI) = 1.15 to 1.40, Ptrend < .001 for digestive system cancers; HR = 1.30, 95% CI = 1.17 to 1.45, Ptrend < .001 for digestive tract cancers (excluding accessory organs); and HR = 1.15, 95% CI = 0.93 to 1.41, Ptrend = .48 for digestive accessory organ cancers. The same associations were stronger with the lifestyle score: HR = 1.47, 95% CI = 1.23 to 1.76, Ptrend < .001 for digestive system cancers; HR = 1.49, 95% CI = 1.14 to 1.95, Ptrend = .001 for digestive tract cancers; and HR = 1.43, 95% CI = 1.17 to 1.73, Ptrend < .001 for digestive accessory organ cancers. Conclusions The findings suggest that interventions to reduce the insulinemic potential of diet and lifestyle may be a means of preventing digestive system cancer.

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