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Study highlights impact of climate change on freshwater fish
Scientists set out to see if living in warm water could affect cold-blooded freshwater fish.
Rising water temperature could affect the cognitive abilities of minnows.

Climate change could leave freshwater fish with bigger brains but reduce their ability to explore their surroundings, according to a study by the University of Glasgow.

The study published in the Journal of Experimental Biology found that fish may undergo significant psychological changes when adapting to rising water temperatures, which could affect their ability to find food.

In the study, scientists set out to see if living in warm water could affect cold-blooded freshwater fish. They fished minnows from the River Kelvin, located close to the university, and split them into two groups.

The team raised one group of minnows in a tank filled with water at the usual temperature of 14°C, the others were raised in tanks heated to 20°C - the predicted temperature of the River Kelvin by the end of the 21st century.

They spent the following eight months observing each minnow's physiology and behaviour, paying special attention to how they interacted with their environment.

By measuring the minnows' oxygen consumption at rest and during exercise, researchers found that the fish in warmer tanks used more energy in both states, suggesting their metabolisms had increased as they adapted to the heat.

The team also noted that minnows from the warmer tanks developed bigger brains than the cooler fish. But despite the increase in brain size, their performance was significantly poorer in a test designed to measure their ability to navigate and find food.

“While the minnows we studied were able to adapt to live in the warmer water, their reduced ability to find their way around in order to catch food does raise some questions,” said lead author Dr Libor Zavorka. “Although we found their brains were larger, they seemed less able to accomplish the simple tasks that minnows carry out every day.”

she continued: “It’s likely that the expansion of brain tissue isn’t accompanied by an expansion of neural density, so their brains don’t provide any additional benefits for being larger. Brain tissue requires a lot of energy to maintain, so it’s likely that the minnows’ bigger brains act solely as a drain on their resources.

“As their metabolisms increase to cope with the larger brains and the increased temperature of the water, they will need to eat more to fuel their bodies – but if they are less able to find food efficiently, they will need to spend more energy looking for it.”

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Government to run free webinars on exporting horses

News Story 1
 The UK government has announced that it will be running two free webinars for horse owners and exporters, explaining what steps to take to export horses from 1 January 2021.

The first webinar will take place on Tuesday 20 October 2020, from 9.30am to 11am. It will cover Export Health Certificate (EHC) requirements from 1 January 2021. Click here to register.

The second webinar will take place on Wednesday 4 November 2020, from 10.30am to 12pm. This session will focus on the steps that businesses need to take to export equines from the UK to the EU. Click here to register.

For more information on exporting horses and ponies after 1 January 2021, please visit the gov.uk website. 

Click here for more...
News Shorts
More cases of African swine fever confirmed in Germany

More cases of African swine fever (ASF) have been confirmed in wild boar in Germany.

According to Pig World, 20 outbreaks have been identified in two districts - Brandenburg, where the original case confirmed on September 10 was found, and near the town of Neuzelle, some 7.5 km away.

The finding represents a further seven cases confirmed by Germany's Friedrich-Loeffler Institute. A Central Crisis Team has been established to coordinate the response to the outbreak.