Behaviour

Deep Trust In Sharks

Jim Abernethy, owner and operator of Scuba Adventures, was the dive operator who showed all of the others that sharks are peaceful animals who want nothing to do with humans as a food source.

He spends most of his time with wild sharks during dives from his liveaboard ship, The Shear Water, at remote sites in the vicinity of the Bahamas, and is on land for only about 40 days a year.

Emma, a tiger shark used in a Shark Week episode, reveals her true nature as a sociable animal when she opens her mouth for James Abernethy to check the injury where he removed a hook

Shark Week Begins

Discovery Channel's Shark Week has begun again. The week-long shark extravaganza was first shown in 1987, and has become a major feature of Discovery's programming. Since its inception, it has been highly profitable for the network, but at what cost?

Sharks can see very well
Sharks can see very well

What are sharks aware of?

Sharks have a very different set of senses than we do, yet the eyesight of the free swimming species is good, so when they look at you, they are seeing you. But you may have the impression that they are using senses other than their eyes most often, and indeed, apart from our shared good eyesight, it is impossible for us to imagine how sharks experience their liquid realm.

Shark behaviour affected by full moon

In a new study, scientists have revealed the diving behaviour of sharks appears to be influenced by the moon, water temperature and time of day. The study was conducted with grey reef sharks, a species commonly found on coral reefs in northern Australia and the Indo-Pacific. Tagged near Palau, about 40 grey reef sharks consisting mostly of adults of females were followed by scientists from UWA and the Australian Institute of Marine Science, who recorded their movement and diving patterns over a two-year period.

European perch
European perch

Fish on psychiatric drugs behave odd

New research conducted by Swedish researchers finds that anxiolytic drugs in surface waters alter animal behaviours that are known to have ecological and evolutionary consequences

Researchers from Umeå University in Sweden examined how perch behaved when exposed to oxazepam, a drug commonly used to treat anxiety disorders in humans.

The scientists exposed the fish to concentrations of the drug similar to those found in the waters near densely populated areas in Sweden.

Male cichlid fish, Pelvicachromis taeniatus, prefer females with a larger pelvic fin, which indicates good body condition, proving that male mate choice may lead to changes in the scale of a female sexual trait.
Male cichlid fish, Pelvicachromis taeniatus, prefer females with a larger pelvic fin, which indicates good body condition, proving that male mate choice may lead to changes in the scale of a female sexual trait.

Female fish tango too

Pelvicachromis taeniatus is a dwarf cichlid from West Africa that is occasionally kept as an aquarium fish In this species, females seek to impress potential mates as well by fanning out their large, violet pelvic fin.

The results, published this month in BMC Evolutionary Biology, also suggest male choice can drive females to evolve exaggerated traits, a finding that disputes the traditional belief that sexual selection is a one-way road, allowing only females to affect male appearance.

Decisions reached through consensus are often more accurate, because they efficiently utilize the diverse information possessed by group members
Decisions reached through consensus are often more accurate, because they efficiently utilize the diverse information possessed by group members

Fish Choose Their Leaders By Consensus

Small groups of sticklebacks (Gasterosteus aculeatus) reach consensus when choosing which of two replica fish to follow. As group size increases, the fish make more accurate decisions.

"It turned out that stickleback fish preferred to follow larger over smaller leaders," said Ashley Ward of Sydney University