Electrophysiology of the heart of an isopod crustacean: Porcellio dilatatus. I. General properties.

Electrophysiology of the heart of an isopod crustacean: Porcellio dilatatus. II. Effects of ions and membrane permeability inhibitors.

Optimization of culture conditions of Porcellio dilatatus (Crustacea: Isopoda) for laboratory test development.

This paper describes the experimental results for optimizing isopod culture conditions for terrestrial ecotoxicity testing. The influence of animal density and food quality on growth and reproduction of Porcellio dilatatus was investigated. Results indicate that density influences isopod performance in a significant way, with low-density cultures having a higher growth rate and better reproduct...

Diurnal rhythms in the synthesis and release of haemolymph proteins in the crustacean Isopoda, Porcellio dilatatus (Brandt), with special reference to vitellogenin.

Synthesis and release of vitellogenin in the crustacean Isopoda, Porcellio dilatatus, were maximal during premolt. At that time, diurnal variations occurred in the haemolymph protein level and in the synthesis and release of vitellogenin and other proteins in the haemolymph. The pattern of variations was always identical and bimodal: the minima were at dusk and at dawn when the maxima occurred ...

Contribution of an electrogenic pump to the resting membrane polarization in a crustacean heart.

1. In the neurogenic heart of the isopod crustacean Porcellio dilatatus, external K+ removal depolarized the membrane (K0 effect) whereas subsequent restoration of K+ resulted in a rapid hyperpolarization (K1 effect). 2. The amplitude of the K1 effect depended on the duration of the prior K+ deprivation and on the subsequent K+ concentration. 3. The membrane resistance slightly increased during...

Evidence for a synaptically mediated decrease in conductance in a crustacean myocardium.

1. In the neurogenic heart of the isopod Porcellio dilatatus, electrical stimulation of the cardio-regulatory nerves at rates greater than 20-25 pulses/s elicited inhibitory junctional potentials (IJPs) in the myocardium. Its cessation was followed by a long lasting hyperpolarization of myocardial membrane (post-stimulus hyperpolarization = PSH). 2. During the PSH the membrane resistance of the...