The 16-year-old boy, from Bangladesh, was fishing in a canal with his friend and spotted two eels.

He caught one of them, but wanting to catch them both, he put the 6.5 inch-long fish between his teeth to free up his hands while trying to catch the other.

Unfortunately, the fish wriggled about, slipped into his mouth and down his throat.

He ran back to his house, where his family saw the fish inside his throat and frantically tried to pull it out.

But because it was alive and moving, it slipped down beyond their vision, according to a case report in the medical journal BMC Research Notes.

The family rushed to a local clinic but when doctors tried to find the fish, it was nowhere to be seen.

The boy was then taken to Dhaka Medical College Hospital - and by this point was having difficulty breathing.

His father explained to doctors he believed there was a fish stuck in his son's throat, but that they couldn't see it.

Doctors examined his throat and saw some lacerations, but could not see the fish either.

They decided to carry out an emergency operation in which they cut the front of his neck and inserted a tube into his windpipe to help him breathe, but they found they couldn't get sufficient air into his lungs.

Five hours after the accident had occurred, doctors spotted the tail fin of a fish through the hole they had created in his windpipe.

They managed to grasp the fin with forceps and pull it out of the throat. The boy's airways cleared immediately. 

The fish was dead when it was pulled out, but it was alive for some time in the boys throat - although it's not clear how long. 

The fish was known locally as Guchi Baim, or an Indian spiny eel, and when measured was found to be about 16 cm long and 2 cm wide. 

'This is the second case I have come across to date,' said Kanu Saha, the boy's surgeon.

'The other was a 45-year-old man who came from a rural village about 300 kilometres away.

'It was 12 hours after he swallowed the fish. Unfortunately he didn't survive.'

The boy's experience mirrors another case from 1965, where a 16-year-old from Pakistan also swallowed a live fish, which he had placed inside his mouth while fishing.

Unusually, his doctors had time to take an X-ray.

A video from 2013 shows the case of a boy treated at Terna medical college in India, who had a fish removed from his throat by surgeons using forceps.

'Cases like this are very rare,' said Mr Saha said of the Bangladeshi boy. 'He is very lucky to be alive.'

He added that a live fish lodging in the windpipe and airways is an 'acute emergency condition'.

It is very difficult to diagnose and manage because the fish can stop the patient being able to communicate, and because different types of fish can get stuck in different areas, he said.

This is because big fish tend to lodge themselves in the back of the throat, while a small, flat or long fish might be able to pass through the throat and get into the airways.

'So a quick short history from accompanying persons especially about the type of fish is crucial to predicting the site of its lodgement in the airway as well as management plan,' Mr Saha concluded.

This video below shows another case of a fish being removed from a boy's throat 

'Avoidance of the tendency of holding the fish between teeth during fishing can prevent this life threatening condition.'

It comes after MailOnline reported on the story of a Brazilian man who had a 2ft long live fish removed from his intestine.

A video showed the moment a surgeon pulls out the eel-like South American lungfish, known to grow up to 4ft10, which had burrowed into the man’s body.

The 39-year-old man, refused to elaborate on how an aquatic animal ended up swimming around inside him.

The procedure was carried out at Hospital Universitário (University Hospital) in Londrina, Brazil, and the video went viral after being posted on the website LiveLeak. 

(dailymail.co.uk)