Chemical Nature and Mode of Stabilization of Egg‐shell in Helicometra pulchella (Rudolphi, 1819) (Digenea: Opecoelidae)

  title={Chemical Nature and Mode of Stabilization of Egg‐shell in Helicometra pulchella (Rudolphi, 1819) (Digenea: Opecoelidae)},
  author={A. M. N. Kalantan and Misbahul Arfin and Mohamed S Alyousif},
  journal={Acta Zoologica},
The chemical nature and mode of stabilization of egg-shell protein in digenetic trematode Helicometra pulchella (Rudolphi, 1819) have been investigated using histochemical techniques. It was found that the egg-shell is stabilized by quinone-tanning together with dityrosine. Other structural proteins (elastin, collagen and keratin-like proteins), glycogen and acid mucopolysaccharides were absent in egg-shell. Tyrosine was present in vitelline cells and immature egg-shell indicating that the… 
Histochemical Nature of Egg-shell of some Trematodes
The chemical nature and mode of stabilization of egg-shell of some Irema ^ es g' I^ different taxonomic groups and inhabiting various hosts and ha it ats ave een i 'g .
Only one snapper fish and a small proportion of the silver pomfrets were found infected with the nematode, Hysterothylacium sp.
A review of the genus Helicometra Odhner, 1902 (Digenea: Opecoelidae: Plagioporinae) with a key to species including Helicometra overstreeti n. sp. from the cusk-eel Luciobrotula corethromycter Cohen, 1964 (Ophidiiformes: Ophidiidae) from the Gulf of Mexico
This study describes a new species of Helicometra from the cusk-eel Luciobrotula corethromycter Cohen, 1964 collected from 1,280 m depth in the northwestern Gulf of Mexico, and it represents the first report of a parasite from the genus LuciOBrotula Smith and Radcliffe in Radcliffe, 1913.


Presclerotized eggshell protein from the liver fluke Fasciola hepatica.
A major eggshell precursor protein with an apparent molecular weight of 31,000 and pI of 7.4 was isolated from the vitellaria of Fasciola hepatica, which is unique in containing rather high levels of the amino acid 3,4-dihydroxyphenylalanine (DOPA).
The phylogeny and chemical diversity of quinone-tanned glues and varnishes.
  • J. Waite
  • Biology, Chemistry
    Comparative biochemistry and physiology. B, Comparative biochemistry
  • 1990
A technique for the histochemical demonstration of polyphenol oxidase and its application to egg-shell formation in helminths and byssus formation in Mytilus
The evidence for the view that the egg-shell in trematodes, in certain cestode groups, and in turbellarians, is a quinone-tanned protein secreted by the so-called ‘vitelline’ glands, is summarized.
The structure and permeability of the shell and vitelline membrane of the egg of Fasciola hepatica
The egg shell of Fasciola was investigated by electron microscopy and found to consist of a fine reticulum of fibrils and it was suggested that the original protein was of a simple fibrous type.
The amino acid metabolism of a developing insect cuticle: the larval cuticle and puparium of Calliphora vomitoria. II. The non-specific hydroxylation of aromatic amino acids and the production of polyphenols by the cuticle
  • R. Dennell
  • Biology, Chemistry
    Proceedings of the Royal Society of London. Series B - Biological Sciences
  • 1958
The possibility that the larval cuticle of Calliphora vomitoria is capable of hydroxylating aromatic amino acids has been examined by incubation with phenylalanine and related amino acids.
The production and functional morphology of helminth egg-shells.
The mechanical and chemical resistance of the egg-shell and the barrier it provides to the entry and loss of material are important in the survival of the free-living stages within the egg.
Egg-shell precursors in trematodes.
In a previous study of the helminth parasites of six species of birds in Puert o Rico (Whittaker et al., 1970, Proc. Helm. Soc. Wash. 37: 123—124), only five cattle egret s Bubulcus ibis (L.) were