Changes in live weight and in the water, Na+ and K+ content of the tissues and faeces have been examined in adult male Periplaneta americana in various states of hydration. During dehydration the haemolymph volume decreases markedly, but the Na+ and K+ concentrations rise only slightly. Less than 25% of the Na+ removed from the haemolymph during dehydration was found to be excreted, but the K+ excreted during dehydration was in excess of that removed from the haemolymph alone. It seems likely that the major tissue for regulating the haemolymph Na+ during dehydration and rehydration is the fat body, in which dehydration causes an increase, and rehydration a decrease, in the Na:K ratio. The Na+ and K+ content of the fat body was found to be variable in both hydrated and dehydrated animals and absolute changes in the ion content of the tissue could not be estimated because of unknown changes in the amount of food reserves and excretory products.
In the field: an interview with Martha Muñoz
Martha Muñoz is an Assistant Professor at Yale University, investigating the evolutionary biology of anole lizards and lungless salamanders. In our new Conversation, she talks about her fieldwork in Indonesia, Costa Rica, the Dominican Republic and the Appalachian Mountains, including a death-defying dash to the top of a mountain through an approaching hurricane.
Call for new preLighters
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preLights is the preprint highlighting community supported by The Company of Biologists. At the heart of preLights are our preLighters: early-career researchers who select and write about interesting new preprints for the research community. We are currently looking for new preLighters to join our team. Find out more and apply here.
Graham Scott in conversation with Big Biology
Graham Scott talks to Big Biology about the oxygen cascade in mice living on mountaintops, extreme environments for such small organisms. In this JEB-sponsored episode, they discuss the concept of symmorphosis and the evolution of the oxygen cascade.
Trap-jaw ants coordinate tendon and exoskeleton for perfect mandible arc
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Trap-jaw ants run the risk of tearing themselves apart when they fire off their mandibles, but Greg Sutton & co have discovered that the ants simultaneously push and pull the mandibles using energy stored in a head tendon and their exoskeleton to drive the jaws in a perfect arc.
Hearing without a tympanic ear
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In their Review, Grace Capshaw, Jakob Christensen-Dalsgaard and Catherine Carr explore the mechanisms of hearing in extant atympanate vertebrates and the implications for the early evolution of tympanate hearing.
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