- 1.
Systolic pressure in the abdominal artery of the lobster Panulirus japonicus (Von Siebold) was decreased by contraction of the cardioarterial valve located at the posterior exit of the heart. Crustacean neurohormones, octopamine and proctolin, induced rhythmic contractions or contracture of the posterior valve but serotonin did not induce valve contracture.
- 2.
Systolic pressure in the posterior artery was reduced when the anterior cardioarterial valves contracted at the same time as the posterior valve. Proctolin caused the anterior and posterior valves to contract. Octopamine caused only the posterior valve to contract and often caused the anterior valves to relax.
- 3.
Proctolin induced depolarizing responses while serotonin often induced hyperpolarizing responses in muscle cells of the anterior and posterior valves. Octopamine hyperpolarized the resting membrane potential of muscle cells in the anterior valves and depolarized the membrane potential in the posterior valve.
- 4.
In some intracellular recordings from the valve muscle cells, slow action potentials followed by a plateau were produced on slow sustained depolarization induced by proctolin or octopamine. The action potential was followed by a large contraction of the valve. Contracture of the valve was associated with a large sustained depolarization in single muscle cells of the valve.
In the field: an interview with Harald Wolf
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In our new Conversation, Harald Wolf talks about his fieldwork experiences working with desert ants in Tunisia to understand their navigation.
Propose a new Workshop
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Our Workshops bring together leading experts and early-career researchers from a range of scientific backgrounds. Applications are now open to propose Workshops for 2024, one of which will be held in a Global South country.
Julian Dow steps down and John Terblanche joins the JEB team
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After 15 years with the journal, Julian Dow from University of Glasgow, UK, is stepping down as a Monitoring Editor. We wish Julian all the best for the future and welcome John Terblanche, Stellenbosch University, South Africa, who is joining the team. Julian talks about his long association with The Company of Biologists and the journal and John tells us about his life and career in this News article.
The capture of crude oil droplets by filter feeders at high and low Reynolds numbers
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Researchers from the University of Montreal, Canada, reveal how tiny filter feeding barnacles and Daphnia entrap and consume minute droplets of crude oil, introducing the pollutant at the bottom of the food chain.
Patterns and processes in amphibious fish
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In their Review, Keegan Lutek, Cassandra Donatelli and Emily Standen discuss the biomechanics and neural control of terrestrial locomotion in amphibious fish. They explore how locomotor mode depends on body shape, physical constraints and phylogeny.
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