Like cars lined up at a car wash, sharks and rays gather at ocean cleaning stations that new research finds are mostly located at seamounts. There, hungry and detail-driven cleaner wrasse fish rid sharks of dead skin, external parasites and other undesirables. The study, published in the latest PLoS One, could help to explain why many oceanic sharks regularly venture into shallow coastal water. At such places, they are more vulnerable to humans – their #1 predator – but cleaning off must be more important to them. Simon Oliver, a researcher at the University of Wales, Bangor, School...

Swimming with the gentle giants of Tofo. Eyes stinging with the wonder of it, my head breaks the surface and a rippling swell sloshes about my ears. Up here all is hysteria, hyper-adrenalized euphoria: 16 goggle-eyed tourists treading water, yelling astonishment through surf and snorkels. Bubble, splash, gurgle . . . “ . . . mazing’’ . . . “ . . . did you see?’’ It’s an understandable reaction when you have just been for a paddle alongside a shark the length of a bus. It didn’t require much courage. No one has been left with a ragged stump where an arm once was; no one’s innards...

Some shark species make “mental maps” of their home ranges, allowing them to pin-point destinations up to 50km (30 miles) away, research suggests. US-based scientists analyzed data from tiger sharks tagged with acoustic transmitters, and found that they took directed paths from place to place. Other species such as blacktip reef sharks did not show this behavior. Writing in the Journal of Animal Ecology, researchers suggest this shows a capacity to store maps of key sites. In addition, it is further evidence that the great fish can navigate, possibly using the Earth’s magnetic...