Scientists used to think that only mammals and birds experienced different sleep states. More recent research, however, has revealed some reptiles and cuttlefish -- another cephalopod and relative of the octopus -- show non-REM and REM-like sleep.
A new study has found that the octopus has ‘quiet’ and ‘active sleep’, with different episode duration and periodicity, and experiences active sleep after a long episode of quiet sleep.
So as the Year of the Shark in 2019 begins, here is a review of how their actions reveal some of their mental states.
Fish feel pain, or don’t they? Despite a growing body of sound evidence that fish do indeed feel pain and are sentient beings capable of all the types of cognition found in the “higher” mammals, with the possible sole exception of the ability to imitate, a group of critics seems to systematically seek to discredit this research. But for what reasons? Ila France Porcher takes a closer look at the stakes involved.
A new style of shark dive has been developed by Jim Abernethy, of Scuba Adventures in Florida. In a dramatic demonstration that “shark huggers” are right, all his guests do with the sharks now is to stroke them! Jim was the pioneer who first demonstrated the peaceful way that sharks will interact with divers, especially when their curiosity has been aroused through the offer of a snack.
While many sharks are solitary predators, some are known to live in groups and are suspected of engaging in complex social behaviors. Meanwhile others simply aggregate due to similar habitat, food, or mating requirements.
Using a novel tagging procedure, scientists in the United States, have discovered that some shark species like to spend their time mixing and chilling out together.
A study by researchers from University of Milano-Bicocca describes observations of adults carrying dead calves and juveniles in 7 toothed cetaceans (odontocetes). The observation was based on 14 events from 3 oceans. The seven species studied were Indo-Pacific bottlenose dolphins, killer whales, Australian humpback dolphins, sperm whales, Risso’s dolphins, short-finned pilot whales, and spinner dolphins.
It was seven in the morning and my coffee hadn’t kicked in yet. The dive guide was giving me a slightly more thorough dive briefing than normal. I wasn’t supposed to wear anything colorful or shiny, and black gloves and a hood were required. Also covered in black neoprene, he was putting on chainmail gloves and told me he’d have a pole with him. He said it was more for the potato cods though, not the sharks.