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At least 19 recordsLinked to original sources
PubMed1992

Comparative investigations of the morphology and chemical composition of the eggshells of Acanthocephala. III. Eoacanthocephala.

Eggshells of the eoacanthocephalans Neoechinorhynchus rutili (Neoechinorhynchidae) and Paratenuisentis ambiguus (Tenuisentidae) were investigated for their fine structure and their chemical composition. The acanthor larvae of P. ambiguus are surrounded by four eggshells (E1-E4) separated by electron-lucent interstices (G1-G4). This resembles the stratification of the eggshells of archiacanthocephalans and palaeacanthocephalans. However, an additional outer envelope (E0) exists in N. rutili. In mature eggs of this species, the broad interstice between E0 and E1 is densely packed with polysaccharides, but the other interstices also showed an intense Thiéry label. In both species, E2 along with its outer protuberances contains keratin, as does E2 in archiacanthocephalans and palaecanthocephalans, whereas E4 does not contain chitin, which contrasts with findings in the eggs of the two other classes of acanthocephalans. The results are discussed with respect to the classification of the Acanthocephala and to their transmission to the intermediate hosts.

Acanthocephala↗
PubMed1979

Fatty acids in female Macracanthorhynchus hirudinaceus (Acanthocephala).

Neutral lipids and phospholipids in the body wall, lemnisci and pseudocoel and neutral lipids of fluid found in the "tube" system of the lemnisci and the lacunar system of the body wall of Macracanthorhynchus hirudinaceus (Acanthocephala) were determined by the technique of thin layer chromatography and gas chromatography (GC). Sixteen different fatty acids from nonpolar lipids were identified as follows: 8:0, 10:0, 11:0, 12:0, 13:0, 14:0, 14:1, 16:0, 18:0, 18:1, 18:2 and/or 20:0, 18:3 and/or 20:1, 20:3, 22:1, 24:1 and 22:6. In addition, there were three unidentified GC peaks corresponding to chain lengths greater than 20 carbons. Sixteen different fatty acids from phospholipids were identified in each of the three fractions analyzed. They were as follows: 10:0, 11:0, 12:0, 13:0, 14:0, 14:1, 16:0, 16:1, 18:0, 18:1, 18:2 and/or 20:0, 20:2, 20:3, 22:1, 24:1 and 22:6. Four unidentified peaks were also observed. There was a significant difference in the percentage of lipid as well as the concentration of particular fatty acids when each fraction was compared. There was also an abundant supply of sterols and glycerides in each fraction.

Acanthocephala↗
PubMedDate not supplied

[Osmotic tolerance and adaptation to hypotonic medium of Echinorhynchus gadi (Acanthocephala, Echinorhynchidae)].

Minimum of the osmotic pressure in the intestine of the cod corresponds to the osmotic pressure of sea water of 10%. The sorbtion level of neutral red by intact E. gadi remained practically unchanged after their maintenance in sea water of 8-10 to 30% during 24 hours (ecological optimum). Specimens of E. gadi transferred from 10 to 4% displayed compensatory recovery of the normal sorbtion level of the dye by the 5th-6th day of the experiment. The ability of Acanthocephala possessing extreme eutelia to a physiological adaptation is indicative of its not obligatory participation of mitotic processes in the acclimation.

Absorption↗
PubMed1992

A comparative study of the host-parasite relationship of Pomphorhynchus patagonicus (Acanthocephala) in two species of fish from Lake Rosario (Chubut, Argentina).

Some aspects of the host-parasite relationships of Pomphorhynchus patagonicus (Acanthocephala) in 2 fish species from Lake Rosario (Chubut, Argentina) were studied. The fish species Patagonina hatcheri (Atherinidae) is autochthonous, and Oncorhynchus mykiss (Salmonidae) is introduced. The host species appears to influence attachment, size, sexual maturity, and distribution of parasites along the digestive tract. In P. hatcheri, an effective major host, parasites are attached firmly to the wall of the gut, well developed, attain a greater size, and a large proportion of females is gravid with ripe eggs. In O. mykiss, an unsuccessful host, there were many unattached parasites that were small and not well developed; gravid females were rare and never had ripe eggs.

Acanthocephala↗
PubMed1979

Carbohydrate transport in Moniliformis dubius (Acanthocephala). III. Post-absorptive fate of fructose, mannose, and galactose.

The initial metabolism of fructose, mannose, and galactose in Moniliformis dubius (M. moniliformis; Acanthocephala) was examined following brief aerobic incubations in 14C-labeled substrate. The pattern of incorporation of radioactivity from 14C-fructose and 14C-mannose into intermediates of hexose metabolism was indistinguishable from that reported elsewhere for the initial post-absorptive metabolism of 14C-glucose under comparable conditions; these hexoses were phosphorylated rapidly following their absorption, and much of the radioactivity absorbed as mannose or fructose was recovered in the nonreducing disaccharide trehalose [alpha-D-glucopyranosyl-(1 leads to 1)-alpha-D-glucopyranoside]. 14C-Galactose was phosphorylated less readily than the other hexoses. More than half of the radioactivity absorbed as galactose was incorporated into disaccharide; some of the galactose-derived disaccharide had properties suggesting the presence of a galactosyl moiety. Incorporation of radioactivity from any of the hexoses into glycogen was minimal. The extensive incorporation of hexose moieties into trehalose or a trehalose-like disaccharide rather than glycogen underscores the probable importance of trehalose metabolism to carbohydrate assimilation in Moniliformis. Physiological factors which might favor trehalose biosynthesis over glycogenesis are considered.

Absorption↗
PubMed1977

A new ganglion in male Moniliformis moniliformis (Acanthocephala).

A new ganglion identified as the bursal ganglion is described from male Moniliformis moniliformis. This ganglion is located adjacent to the pseudocoel and longitudinal muscle fibers and medial to the dorsal lacunar canal about 1 mm from the posterior end of males with non-everted bursa. The ganglion consists of four large club-shaped cells with single nuclei and bipolar neurons. The ganglion cells are paired with one neuron from each cell innervating the opposite side of the worm.

Acanthocephala↗
PubMed1992

Praesomal nerves in Leptorhynchoides thecatus (Acanthocephala: Rhadinorhynchidae).

Investigated by light microscopy, the nerve pathways are described for the first time in the praesoma of a species of Rhadinorhynchidae. The pathways are described for 18 nerves, eight paired and two single, which originate from the cerebral ganglion and a post-ganglionic cell and terminate in the body wall musculature and the proboscis. The location of three commissures formed by these nerves is also described.

Acanthocephala↗
PubMed1976

Histochemical characteristics of the egg envelopes of Acanthosentis sp. (Acanthocephala).

The histochemical and phase contrast observations on the embryonic envelopes enclosing the acanthor of Acanthosentis sp. reveal the presence of three layers. All the three layers were non-refractile during early stages of their formation, and become refringent subsequently. The outer layer loses its refractile property together with affinity for acid and basic dyes when the eggs are fully developed. This layer is neither tanned nor chitinous. The second layer consists of glyco-lipo-proteinous matrix. The polysaccharide moiety is identified to be strongly sulfated acid mucopolysaccharide. The lipid component has been characterized to be KOH resistant and esters of unsaturated fatty acid. The protein is rich in aromatic amino acids. The third and the innermost layer contains chitin and acid mucopoly-saccharides. The protein is rich in sulfur-containing amino acids. Sulphydryl groups were present during early stages of its formation, but forms disulphide cross-links subsequently. Stages in the development of acanthors were characterized with reference to the formation of envelopes. The permeability experiments carried out on fresh eggs using 0.1% aqueous solutions of bromophenol blue, methylene blue, toluidine blue, basic fuchsin and neutral red indicate that the inward diffusion of these substances is prevented subsequent to formation of disulphide groups in the innermost layer. The results further indicate that the embryo derives nutritive requirements from the fluid of pseudocoel of the female worm through th envelopes covering it.

Acanthocephala↗
PubMed1978

[Electron microscopic and morphometric investigations of the integument of Acanthocephala (Aschelminthes) (author's transl)].

The integument of the acanthocephalans Echinorhynchus gadi, Acanthocephalus lucii, Polymorphus minutus and Macracanthorhynchus hirudinaceus have been investigated by stereoscan and transmission electron microscopy. The absorptive surface is considerably increased by invaginations of the outer plasma membrane (pore canals and vesicles). The rate of this enlargement has been calculated using morphometric methods. The values range from 20 to 62. The values are compared to values obtained from other gutless parasitic helminths and from the free-living rotifers which are presumably to be regarded as closely related to the acanthocephalans.

Acanthocephala↗
PubMed1992

Comparative investigations of the morphology and chemical composition of the eggshells of Acanthocephala. II. Palaeacanthocephala.

Eggshells of the palaeacanthocephalans Acanthocephalus anguillae, Pomphorhynchus laevis and Polymorphus minutus were investigated for their fine structure as well as their chemical composition. The acanthor larvae are surrounded by four eggshells (E1-E4) separated by interstices (G1-G4). Immature eggs do not exhibit the complete set of eggshells. The chemical composition of the outermost, thin eggshell (E1) remains unknown. E2 is supplied by outer filaments of different strength; it contains keratin, which was localized electron microscopically using anti-keratin. In P. laevis and P. minutus, E3 seems to contain glycoproteins, which could not be visualized in this eggshell of A. anguillae. The innermost eggshell (E4) uniformly contains chitin. The electron-lucent interstices of the eggs of P. laevis and P. minutus are rich in polysaccharides and/or proteoglycans, whereas those of A. anguillae contain low amounts of such substances. The differences observed in the abundance of carbohydrates are discussed with respect to the life cycles of the three acanthocephalans.

Acanthocephala↗