How guppies dodge predators


This 2013 video is called Guppy (Poecilia reticulata) evades strike from pike cichlid (Chrenicichla alta).

From the University of Exeter in England:

‘Matador’ guppies trick predators

June 11, 2020

Trinidadian guppies behave like matadors, focusing a predator’s point of attack before dodging away at the last moment, new research shows.

The tiny fish (10-40mm) draw attention by turning their irises black, which makes their eyes very conspicuous.

This encourages pike cichlids — a large fish that is the guppies’ main predator — to charge at their head rather than their body.

The international study, led by the University of Exeter, found guppies then use their lightning reflexes to whip their head out of the way, causing the predators to miss, before swimming away.

Many fish, including guppies, often approach their predators to find out if they are hungry and thus a current threat.

“We noticed that guppies would approach a cichlid at an angle, quickly darkening their eyes to jet-black, and then waiting to see if it would attack,” said lead author Dr Robert Heathcote, who undertook the experimental work at Exeter and is now at the University of Bristol.

“Cichlids are ambush predators, lying in wait like a coiled spring before launching themselves at their prey.

“The guppies actually use their eyes to get the predator’s attention, causing them to lunge at a guppy’s head rather than its body.

“Whilst it seems completely counterintuitive to make a predator attack your head, this strategy works incredibly well because guppies wait until the predator commits to its attack before pivoting out of the way.

“The speed of the whole interaction is extraordinary — at around three-hundredths of a second — so was only observable using a high-speed camera.”

Many animals are known to use “conspicuous colouration” for purposes such as communication, attracting mates, startling predators and advertising toxicity.

This paper demonstrates a previously unknown divertive strategy — but the researchers think it may be used by other species too.

“We don’t know for sure, but it seems highly likely that other animals also use a ‘matador’ strategy like the one we have identified in guppies,” said Professor Darren Croft, of the University of Exeter.

“Eyes are one of the most easily recognised structures in the natural world and many species go to great lengths to conceal and camouflage their eyes to avoid unwanted attention from predators.

“Some species, however, have noticeable or prominent eyes and, for the most part, it has remained a mystery as to why this would be.

“Our latest research gives new insight into why ‘conspicuous’ and colourful eyes have evolved.”

The study was conducted in several stages:

  • Guppies were observed approaching pike cichlids, often turning their irises black.
  • The attack strategy of cichlids was tested by placing them in tanks with realistic robotic guppies. When robotic guppies had black eyes, cichlids tended to strike towards the head rather than towards the centre of the body.
  • By placing guppies and cichlids in a tank (with a transparent screen to prevent the guppies being eaten) and filming with high-speed cameras, researchers observed the success rates of cichlid attacks. Guppies that turned their eyes black were 38% more successful at escaping than guppies with normal eye colouration.
  • Findings were then confirmed using footage of a previous study in which cichlids were filmed hunting real guppies.

“This project presented a wonderful range of technological challenges, including the creation of robotic guppies matched to the colour vision of pike cichlids, and high-speed computer tracking of guppies as they escaped,” said Dr Jolyon Troscianko, of the University of Exeter.

“These advances allowed us to work out whether an attack would have been successful without needing to run life-and-death experiments with fish.”

One surprising finding was that larger guppies were better than smaller ones at escaping using this method.

“As animals become larger, they generally become less agile. If larger prey don’t have weapons or other ways of defending themselves, this can result in them being easier for predators to catch,” said Dr Heathcote.

“By turning their eyes black, larger guppies actually reverse this phenomenon.

“Bigger guppies with black eyes are better at diverting and escaping predator attacks.

“Since bigger animals produce more or larger offspring, it would be really exciting to find out if the animals that use these kinds of strategies have evolved to become larger.”

Professor Indar Ramnarine, of the University of the West Indies, St Augustine Campus, said: “We first discovered this particular behaviour in guppies several years ago and wondered what was the significance of this. Now we know.”

Previous research has shown that guppies also turn their eyes black to display aggression towards each other.

Dr Safi K. Darden, of the University of Exeter, said: “We knew that changing iris colour was somehow involved in interactions with other guppies, but when we saw that guppies performing predator inspections were also changing the colour of their irises, we figured that something really interesting must be going on.

“It is thrilling to have had such a skilled team with diverse expertise come together to be able to investigate this behaviour in such detail.”

COVID-19 disaster, worldwide


This 11 June 2020 video says about itself:

The coronavirus pandemic is having a devastating impact on refugees around the world.

Preventative measures like social distancing and frequent hand washing are often difficult to implement in crowded camps.

The aid agencies helping the refugees are struggling as well.

Wealthy nations in Europe, North America and the Middle East are slashing donations, and keeping that money at home to tackle the economic fallout of the pandemic.

Oxfam, one of the world’s largest charities, laid off nearly 1,500 staff and pulled out of 18 countries last month.

A recent survey estimated that global government aid will drop by 25 billion dollars by 2021.

So how do we ensure protection for some of the world’s most vulnerable people?

COVID-19 cases spike across the United States. By Jacob Crosse, 12 June 2020. Twelve US states—Oregon, Idaho, Nevada, Utah, Arizona, New Mexico, Michigan, Arkansas, Florida, South Carolina, Delaware and Hawaii—have all seen a 25 percent or more spike in average cases within the last week.

Translated from Dutch NOS radio today:

Trump campaign team: complaining after contagion at election meeting not possible

In violation of the advice to avoid busy spots because of the coronavirus, President Trump will resume his massive campaign meetings this month. The thousands of people expected in Tulsa, Oklahoma, on June 19, must promise not to sue the campaign team if they become infected.

Below the event registration form, there is a short text, in which signatories admit the risk of contamination. By registering, attendees automatically undertake to accept all coronavirus-related risks and in no way hold the campaign staff accountable “for any illness or injury”.

Not just COVID-19. Also, injuries caused by Trump’s bouncers violently ejecting people from the rally. For heckling. For being black. For being a Muslim. For being a journalist.

The meeting in Tulsa is the first since a major lockdown in the United States three months ago. Trump’s campaign events are usually attended by thousands of supporters and there are concerns about the spread of the virus in the masses.

More than two million infections and nearly 114,000 deaths have been diagnosed in the US. Yesterday, a leading Harvard University expert warned that the death toll could reach 200,000 in September.

“They treat us like we are slaves”. Detroit Flex-N-Gate workers denounce sweatshop conditions. By J. Cooper, 12 June 2020. Workers are facing intolerable conditions after the reopening of the auto parts plants.

Brazilian delivery workers strike in defense of their lives. By Tomas Castanheira, 12 June 2020. Delivery workers have been carrying out strikes and protests in Brazil since April, connected to delivery workers’ strikes around the world in countries like Spain, Ecuador and Argentina.

From the World Socialist Web Site, 12 June 2012:

Wildcat strike by cleaners at London school

Migrant workers employed as cleaners at the UK Ark Global academy school in south London stage a wildcat strike June 4.

The United Voices of the World (UVW) union members work for outsourcing company Ridge Crest. They walked out over wage arrears going back in some instances to January 2019. They are also demanding to be paid statutory sick pay, pay of £12 an hour, and face masks for COVID-19 protection. The UVW is currently balloting them for official strike action.

Sea otter recovery helps other wildlife, economy


This January 2020 video says about itself:

Sea Otters Hold Hands To Survive The Dangers Of The Open Ocean | BBC Earth

Sea otters face great danger in the open ocean; can this family brave the waves and stick together?

From the University of British Columbia in Canada:

Recovery of sea otter populations yields more benefits than costs

New model puts dollar value on ecological transformations driven by otters

June 11, 2020

Summary: Researchers have created a new model to evaluate the long-term economic benefits of top predator recovery, using sea otter recovery along the west coast of Canada as a case study.

Since their reintroduction to the Pacific coast in the 1970s, the sea otters’ rapid recovery and voracious appetite for tasty shellfish such as urchins, clams and crabs has brought them into conflict with coastal communities and fishers, who rely on the same valuable fisheries for food and income.

But the long-term benefits of sea otter recovery — such as healthier kelp forests, higher fish catches, carbon storage and tourism — could be worth as much as $53 million per year, according to new UBC research. If well-managed, these economic benefits could offset commercial losses to shellfish fisheries of $7 million per year.

The study, published today in Science, is the first regional economic analysis of the costs and benefits of sea otter recovery along the west coast of Vancouver Island. Critically, it offers a new modeling framework to evaluate the significant long-term ecological changes driven by a top predator like the sea otter.

“Our work offers a glimpse into a future where otter populations have recovered to an estimated 5000 animals, and have fully reoccupied their historic range,” said lead author Edward Gregr, an adjunct professor at the Institute for Resources, Environment and Sustainability at UBC. “We found that coastal ecosystems with otters present are almost 40 per cent more productive. In the long run, that equates to higher fish catches worth $9 million, carbon storage worth $2 million and tourism opportunities worth $42 million per year.”

That’s because the hungry otters drive huge transformations to their local ecosystems: by keeping urchin populations in check, they allow kelp forests to recover. Healthy kelp forests, in turn, sequester carbon and support abundant marine life, from salmon and lingcod to seals and whales.

For the analysis, researchers integrated local ecological field studies with available economic data and a recent tourism study, and accounted for uncertainties in future values and potential interactions among the species in the coastal ecosystem.

“It’s clear that humanity must reverse the decline in biodiversity if we want to achieve a sustainable future,” said co-author Kai Chan, a professor at IRES and the Institute for the Oceans and Fisheries at UBC. “This study demonstrates that restoring key species to ecosystems can also have great benefits for people, and could serve as a useful framework for evaluating top predator recovery elsewhere.”

But, the researchers warn, the costs and benefits of such large ecosystem reorganizations are often not equally distributed. In British Columbia, future management decisions must consider the implications for local Indigenous communities and fishers, who are experiencing the losses from shellfish fisheries more acutely.

For example, while commercial fishers are likely to adapt to fewer crabs in shallow waters by fishing in deeper waters, Indigenous or recreational harvesters with more restricted access may not be able to.

“Other costs and benefits — like food security, culture and tradition — are also considerable, but they are more difficult to value in dollars,” said Gregr. “Going forward, we want to scale the model down and incorporate such impacts at the local level.”

The researchers hope that quantifying the impacts of ecological transformations more broadly will help mitigate conflicts, promote public acceptance of ecosystem change and help identify opportunities for local communities.

“Sea otters co-existed with and were managed by the Indigenous Peoples of this region for millennia before they were hunted to near extinction by the maritime fur trade,” said Gregr. “Their recovery is a golden opportunity for the Government of Canada to reconcile coastal fisheries management with local communities and regional stakeholders to ensure strong, healthy coastal communities and thriving otter populations.”

Coronavirus, Bolsonaro’s Brazil and elsewhere


This 12 June 2020 video says about itself:

Brazil‘s symbolic COVID-19 ‘graveyard’

Brazilians critical of their government’s ambiguous response to a surging coronavirus pandemic dug 100 graves and stuck black crosses in the sand of Rio’s Copacabana beach in a tribute to the people who have died so far.

So far, 40,000 Brazilians have died from COVID-19 and still counting. These are conservative official figures.

The crosses remind me of the many crosses put on a beach in the USA, to commemorate the thousands of soldiers then-President George W Bush sent to his wars to die.

Dutch NOS radio reports today that a fanatical Bolsonaro supporter has smashed some of the crosses.

NOS radio also reports today:

Many coronavirus patients [not admitted to hospitals, so supposedly ‘mild’ coronavirus patients] still have serious health problems months after their healing. This is evident from a survey conducted by the Lung Fund and the CIRO knowledge center among 1622 people with such complaints.

More than 90 percent of the respondents say they have problems with simple daily activities, such as walking. 85 percent say he or she was in good health before the infection. Now that is only 6 percent.

How shipworms can help human health


This 2018 video says about itself:

Giant Shipworm | World’s Weirdest Animals

Creeping and crawling below the earth’s surface is a worm you’ll have to see to believe, on this episode of world’s weirdest animals we bring you the shipworm.

-found in the Philippines
-lives in a long hard shell
-it’s long slimy like a worm but 3 feet long
-have been documented since the 18th century
-only recently have scientists have had access to living forms of the creature
-they belong to the mollusks family such as scallops, mussels and oysters
-they shell they inhabit is made of calcium carbonate
-they can be found in shallow lagoons immersed in mud, they are basically the geoduck of the Philippines
-they burrow in rotting pieces of wood and feed on bacteria in the mud, these creatures essentially hang upside down with a siphon protruding out of the mud and their mouth at the bottom of the tube
-the y-shaped siphon is used for taking in and expelling water
-the surrounding mud emits hydrogen sulfide which is used by the gills of the shipworm to produce carbon which they feed off
-simplified they convert chemicals from rotting wood into fuel which is similar with plants and sunlight.
-the hydrogen sulfide-rich mud also reeks of rotten eggs which apparently means mealtime for the shipworm.
-the shells of shipworms have been found for some time as they are very sturdy but only recently have scientists found the live shipworm itself
-the worms were once common all over the world but their numbers have declined
-to make things worse for the shipworm their shells are quite valuable to collectors
-prior to this shipworm finding, the best information scientists had was from drawings of a poorly preserved 1960s specimen that was dead
-when scientists opened the shell they said it was a lot like opening an egg and were shocked by how black the shipworm is and how beefy they are

From Washington State University in the USA:

Compound in the gills of clams may fight common infections

June 11, 2020

A compound discovered in the gills of wood-eating clams could be the solution to a group of parasites responsible for some of the world’s most common infections.

That compound is tartrolon E, a byproduct of bacteria that help shipworms, a group of saltwater clams, digest the wood they eat.

According to research recently published in PLOS Pathogens, the compound, unlike any other, is proven to kill causal parasites for malaria, toxoplasmosis, cryptosporidiosis, theileriosis and babesiosis.

“There are compounds that work against the individual parasites, but to find one that works against this entire group, that is what made this unique,” said Roberta O’Connor, an associate professor in Washington State University’s Veterinary Microbiology and Pathology unit, and first author on the paper.

While there are already effective drugs for many of the parasites mentioned here, O’Connor said this group of parasites, called apicomplexans, readily develops drug resistance.

“Development of new, effective drugs against apicomplexan parasites is an ongoing need for human and veterinary medicine,” she said.

One of those parasites in need of a more effective remedy is Cryptosporidium.

Cryptosporidium, a waterborne zoonotic parasite, is a major cause of diarrhea in children, immunocompromised patients, and in newborn animals worldwide. The parasite infects millions of humans and agricultural animals annually.

In addition to killing this class of parasites in vitro, tartrolon E was able to kill Cryptosporidium in newborn mice.

Beginning this summer, WSU researchers will test the compound against Cryptosporidium in lambs.

Currently, nitazoxanide is the only drug approved by the Food and Drug Administration to treat cryptosporidiosis.

“Nitazoxanide doesn’t work well for those [patients] who are immunocompromised or malnourished and those are the people most vulnerable to Cryptosporidium,” O’Connor said.

O’Connor is the principal investigator on the study which will characterize the specific effects of tartrolon E on Cryptosporidium parasites. Villarino will lead the pharmacokinetics portion of the study in immunocompromised mice to further assess tartrolon E’s effectiveness and optimal dose regimens.

The research is made possible by a recently awarded 5-year, $1.6 million grant from the National Institutes of Health.

“We will define how the drug behaves in the body and how much of the drug is needed to control Cryptosporidiuminfection,” Villarino said. “We want the maximum effect with minimal adverse effects.”

This aspect of the research on the compound is a key component for drug development.

“This could have a significant impact on human and veterinary medicine because there is no other drug that can effectively treat this condition,” Villarino said.

O’Connor and Villarino are hopeful tartrolon E will lead to a clinically developed drug but they know it is a long way to get there.

“Tartrolon E is obviously hitting some system that is common to [all] these parasites,” O’Connor said. “Even if this compound isn’t successful, if we can determine the mechanism, we will have identified a common drug target for all these parasites.”

Demonstrating against racist police murders, a crime?


This 12 June 2020 video from the USA says about itself:

Medic Shares Advice for Staying Safe at Protests After Getting Arrested | NowThis

‘Their guns were all pointed at our heads’ — This medic was forcefully arrested by police while providing aid to protesters after curfew.

In US news and current events today, police detained a 23-year-old medic and her friends while they were out at protests trying to help people. Sarah Fenno was one of hundreds arrested on May 31 during Black Lives Matter protests in Cincinnati, Ohio. Fenno was held inside the police station, though many others had to sit outside all night. Fenno says that her and her friends were all denied medical attention, food, and water. Watch to hear more about her experience.

From daily The Morning Star in Britain, 11 June 2020:

Ministry faces court fight on riot gear sales to US

THE BRITISH government is facing legal action over riot gear exports to the US after Scotland voted to endorse a ban this week.

In a bid to stop sales of equipment including CS gas, tear gas and rubber bullets to the US following outrage over President Donald Trump’s brutal crackdown on anti-racist protesters, lawyers have begun the first steps in a potential High Court battle.

The pre-action protocol letter, sent to International Trade Secretary Liz Truss, asks for confirmation of whether a decision has been made over the suspension of licences which allow firms to export such equipment to the US.

Would-be führer Trump steps up coup plotting. 12 June 2020. The president is seeking to manufacture a pretext for violent repression and the establishment of an authoritarian regime in America: here.

National Guard fired the shot that killed David McAtee in Louisville during protest against police violence. By Kevin Reed, 12 June 2020. Laboratory tests have determined that McAtee was shot and killed by a member of the Kentucky National Guard during an assault on protesters last week.

Sri Lankan police violently suppress protest against the killing of George Floyd. By our reporters, 12 June 2020. The police attack is a message from the Rajapakse administration that it will not tolerate any opposition from workers, young people and the poor.

Sri Lankan SEP to hold online meeting against the murder of George Floyd in the US. 11 June 2020. The SEP will hold an online public meeting, titled “The international wave of struggles against the killing of Floyd in the US and plans for capitalist dictatorship”, on Sunday, June 14 at 3 p.m. local time: here.

Australian PM calls for mass arrests at protests against police violence. By Oscar Grenfell, 12 June 2020. Echoing Donald Trump, Scott Morrison declared that demonstrations had been “hijacked by left-wing radicals” who were pursuing “their own political agendas.”

New Zealand Police ends armed units after widespread opposition. By Tom Peters, 12 June 2020. Faced with overwhelming opposition to armed officers, the Labour Party-led government and the police have temporarily withdrawn a push to introduce Armed Response Teams.