Key genes that help burrowing frogs avoid muscle wastage while they are dormant have been discovered by researchers. These genetic insights could help prevent muscle atrophy in bedridden human patients, or even astronauts. For most mammals, including humans, when muscles are inactive over a long period, they lose condition and waste away. However, some animals can remain dormant for several months and yet suffer minimal muscle damage, including green-striped burrowing frogs, the focus of this study.
Like humans, fish prefer to group with individuals with whom they are familiar, rather than strangers. This gives numerous benefits including higher growth and survival rates, greater defense against predators and faster social learning. However, high carbon dioxide levels, such as those anticipated by climate change models, may hinder the ability of fish to recognize one another and form groups with familiar individuals.
Sharks were a tolerant bunch some 50 million years ago, cruising an Arctic Ocean that contained about the same percentage of freshwater as Louisiana's Lake Ponchatrain does today, says a new study. The study indicates the Eocene Arctic sand tiger shark, a member of the lamniform group of sharks that includes today's great white, thresher and mako sharks, was thriving in the brackish water of the western Arctic Ocean back then. In contrast, modern sand tiger sharks living today in the Atlantic Ocean are very intolerant of low salinity, requiring three times the saltiness of the Eocene sharks in order to survive.