Eurasian ruffe swimming at night, video


This is a video about an Eurasian ruffe swimming at night.

Diver Jos van Zijl from the Netherlands made the video.

Sharks have individual personalities, new study


This video is called Jonathan Bird’s Blue World: Shark Biology.

From the BBC:

2 October 2014 Last updated at 03:17 GMT

Sharks can be ‘social or solitary’

By Jonathan Webb Science reporter, BBC News

The most feared predators in the sea have individual personalities that affect how readily they socialise, according to a study by UK scientists.

Individual sharks, studied in groups of ten, showed consistent social habits – either forming groups with other sharks or finding camouflage on their own.

When a group was shifted into a new environment, individual sharks showed the same patterns of behaviour.

This is the first study to show that sharks have their own personalities.

The research was done in large tanks at the Marine Biological Association of the UK, in Plymouth, in collaboration with the University of Exeter. The findings appear in the journal Behavioural Ecology and Sociobiology.

Strategies for safety

Ten different groups, each containing ten small spotted catsharks, were each studied in three different situations. Some were complex environments with lots of rocks and other features, and some were simple tanks with gravel on the bottom.

Even though the overall number and size of sub-groups among the ten sharks often changed between environments, the individual sharks that tended to form big groups continued to do so, no matter what the situation.

Similarly, the more antisocial specimens remained on their own, or in much smaller groups.

“The results were driven by different social preferences, that appeared to reflect different strategies for staying safe,” said lead author Dr David Jacoby, a behavioural ecologist now working at the Institute of Zoology in London.

“Well-connected individuals formed conspicuous groups, while less social individuals tended to camouflage alone, matching their skin colour with the colour of the gravel in the bottom of the tank,” Dr Jacoby said.

Prof William Hughes, an animal behaviour expert at the University of Sussex, said he was impressed by the level of detail in the results.

“They recorded which shark was hanging around with which other sharks, on a number of occasions across two days – so they got a very, very detailed picture of the social relationships,” he told BBC News.

Prof Hughes said the experiments could be compared to watching a group of people: “Imagine if we took ten work colleagues and plonked them in a bar, and observed which individuals sat with which other individuals over the course of an evening.”

Then imagine repeating the experiments in a nightclub, rather than a bar. And then perhaps back at work – and then, repeating the whole exercise with nine other groups of ten colleagues.

Individual people would tend to form bigger or smaller groups no matter what the situation, much like the sharks.

“It’s a very nice piece of work. It provides some pretty reasonable evidence that sharks show a form of social personality,” Prof Hughes said.

Comparing notes

The result is not altogether surprising, he added. Over the last decade or more, a minor revolution in animal behaviour research has amassed similar evidence for consistent, individual behaviour differences within a large number of species.

“Probably all animals show it, to some extent,” Prof Hughes explained.

Jean-Sebastien Finger is a PhD student at the Humboldt University in Germany, investigating the existence of personalities in another species, the lemon shark. His work is based at the Bimini Biological Field Station in the Bahamas.

Mr Finger agrees that the result was not unexpected. “Personality has been seen everywhere – in almost every taxon of animals,” he told the BBC.

“Sharks haven’t really been tested before.”

Mr Finger said his own research had found “strong preliminary evidence” for consistent differences in lemon sharks.

“I think it will be quite good to compare the two species,” he said.

Dr Jacoby is also looking forward to comparing notes. “I’d expect there to be similar sorts of traits in other species,” he said, adding that the Bahamas project looks at sharks in the wild, which is important.

“Ours was captive study – but it gave us an opportunity to manipulate and control these experiments, which is unusual in shark studies.”

North American fish in the Netherlands


This video from the USA about Atlantic croakers says about itself:

River fish – Baby Croakers

10 August 2014

Croakers — hundreds of them — are everywhere. They are cute and unfortunately for them, taste good. We let them go.

Translated from Ecomare museum in the Netherlands:

A fish that looks like an Eurasian ruffe and makes a croaking sound can really only be one species; an Atlantic croaker. These fish normally live along the Atlantic coast of North America. Every now and then one is caught in the Netherlands. Until now, they were known from the North Sea and the Marsdiep. On September 9 Jan van Triest of the fishing boat HK17 caught one in the Markermeer lake, near Lelystad. This is the first catch from really fresh water.

Baby nursehound shark born


Baby nursehound shark

This is a photo of a baby nursehound shark; hatched recently from an egg in the aquarium of Ecomare museum on Texel island in the Netherlands (with a stickleback in the background of the photo).

Carp, underwater video


Diver John de Jong made this video about carp in the Netherlands.

Carboniferous fossil discoveries in England


This video is called The Carboniferous Period.

From Wildlife Extra:

Yorkshire‘s hidden fossil haven reveals an exotic past

A derelict mining tip in Doncaster has given up its 310-million-year-old secrets after a host of new fossils – including some fossilised plants and creatures that may even be new to science – were found. One of the most exciting finds was that of a fossilised shark egg case, hinting at Yorkshire’s more exotic history.

Also among the fossils were some horseshoe crabs and previously unrecorded seed pods, all of which were found in preserved rocks that formed within the coal and shale deposits in what is one of the few fossil locations of its kind left in the UK.

The tip, located in Edlington, southwest of Doncaster, has been identified as being the only tip in the borough where fossils could still potentially be collected. All others in the area have been landscaped, or turned into parks, leaving any fossils that may be lying beneath inaccessible.

Palaeontologist Dean Lomax, a visiting scientist at the University of Manchester’s School of Earth, Atmospheric and Environmental Sciences, described what the fossils indicate Yorkshire might have been like hundreds of millions of years ago: “The fossils unlock a window into a long distant past, buried deep beneath residents’ feet. They are proof that parts of Yorkshire were once a tropical water-logged forest, teeming with life that may have looked something similar to today’s Amazon delta, a mix of dense forest, lakes, swamps and lagoons.

“The shark egg case is particularly rare and significant, because it’s soft bodied and an unusual object to find fossilised. We hope that future organised collecting of the site may reveal further rare discoveries, such as dragonflies, beetles, spiders and further evidence of vertebrates. And who knows, maybe we will even find the actual shark.”

It is hoped that further fossil specimens unearthed at the site will continue to be found. Speaking from Doncaster Heritage Services, Peter Robinson said: “We hope this important discovery will encourage ex-miners from the borough to bring forward and donate fossil specimens from the now defunct collieries, which were collected whilst extracting coal from the pit face. We have heard many stories of some of the wonderful fossils that have been found.”

The fossils are being safely stored at Doncaster Museum and have been integrated into the museum’s fossil collection.