Effect of crustacean eyestalk extracts on carbohydrate levels in the South Indian scorpionHeterometrus fulvipes (Koch)

Summary Injection of eyestalk extracts of freshwater crab and marine prawn caused elevation of haemolymph sugar level, and decrease in free sugar and glycogen levels, in the hepatopancreas of the scorpion.     

Structural diversity of communicating intercellular junctions (gap junctions) in the posterior cecal epithelium of the crustacean Orchestis]

Two types of gap junction are described, they are different in the size, the spacing and the polarity of their intramembrane particles. The dense type shows two kinds of particles which rather remain joined to the P fracture face. The loose type shows larger and more spaced out particles which rather are held by the E fracture face. These observations demonstrate that one needs to shade the distinction between P-type gap (Vertebrate) and E-type gap (Arthropoda).     

Ultrastructure of the oocyte follicles in the crustacean amphipod Orchestia gammarellus (Pallas)]

The follicle cells of the Crustacean Amphipoda Orchestia gammarellus produce syntheses at the level of the ergastoplasm and the Golgi body. No secretary cycle is observed. A complex but permeable network of intercellular spaces provides a path for possible transfollicular penetration for the exogenous fraction of the vitellus.     

Fine structure of a neurosecretory axon in a crustacean skeletal muscle

Résumé Un axone neuro-sécréteur à extrémités localisées dans le muscle squelettique du craneCarcinus est décrit. Ces extrémités contiennent 6 sortes de vésicules ayant les diamètres de 1300 a 3700 . Il est suggéré que es petites vésicules correspondent à la phase de rétablisement de la membrane, pendant la décharge des granules euro-sécréteurs. On suppose aussi que cet axone peutêtre l'intermédiaire d'une influence trophique du nerf sur le muscle.

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I am most grateful to Mr.K. Oates and Mr.G. R. Abram for excellent technical assistance.

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Supported by a Research Studentship from the Science Research Council.     

Coagulation of hemolymph in Crustacea. Electrophoretic demonstration of a plasmatic component in the course of hemostasis in a group A crustacean (Cancer pagurus)]

Coagulation assays in vitro of plasmatic extract from Cancer pagurus reveal the existence of a plasmatic coagulation in this species which was considered as yet as lacking a such process. Electrophoretical analysis of this extract before and after coagulation shows the presence of a plasmatic component probably involved in the formation of the clot.     

Molecular weight of lipovitellins during egg development in the crustacean amphipod Orchestia gammarella (Pallas)]

Egg lipovitellins of Orchestia gammarella tested by electrophoresis on gels of different acrylamide concentrations, following the procedure of Hedrick and Smith (1968), display a migration pattern identical to that of proteins with molecular weights of congruent to 3.2 x 10(5) (lipovitellin I) and congruent to 5.5 x 10(5) (lipovitellin II) respectively. Since their molecular weight remains constant during embryogenesis, the changes of their relative mobility in disc gels indicates alterations in their ionic charges.     

Osmotic behaviour of isolated axons of a euryhaline and a stenohaline crustacean

Résumé Les axones isolés du crustacé euryhalinEriocheir sinensis sont capables d'effectuer une régularisation de volume lorsqu'ils sont soumis à des chocs hypo-osmotiques. Les mécanismes pouvant être impliqués dans ce processus sont discutés.

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Chercheur qualifié du Fonds National de la Recherche Scientifique.     

Calcium transients in a crustacean motoneuron soma: Detection with arsenazo III

Summary Long lasting action potentials can be triggered in crayfish giant motor neurons by a short depolarizing pulse under different conditions. The concomitant increase in absorbance of the Ca indicator arsenazo III preloaded into the soma, confirms observations suggesting that these potential changes are related to a Ca inward current through the some membrane.     

Biochemical and immunochemical evidence for the origin of the spermatophore material inGlossina morsitans morsitans Westwood

Summary Protein patterns in secretions from fully differentiated male accessory reproductive glands (ARG), spermatophore (Sp) and testes (Te) of the tsetse,Glossina morsitans morsitans Westwood, were determined by isoelectrofocusing. Isoelectrofocusing patterns of total ARG proteins and those of Sp were remarkably similar. At least 27 bands were detected in ARG and Sp. Out of these, 13 were major protein bands and isoelectrofocused in the pl range of 4 and 6.55. About 10 of these 13 were found to be acidic. Ouchterlony immunodiffusion and straight line immunoelectrophoresis showed that male accessory reproductive gland secretory proteins and spermatophore share common immunological characteristics which are different from those of the testes.