The UN declared the mouth of the leatherback turtle the most terrifying thing in the world. I’m not sure about that. I can think of more terrifying things but it is pretty horrible and it does attract one’s attention.
Perhaps you had the same thought when you first saw pictures of the interior mouth of a leatherback turtle. I thought of the shark but even the shark does not have ‘teeth’ like these. But the thing is this: they are not teeth although they look very much like them.
They are papillae. They are sharp and they are made of keratin which is the same material that makes our nails and our hair. As you can see, they are backward facing. Their purpose is to stop jellyfish being regurgitated which would otherwise happen because they swallow lots of water with the jellyfish which they have to regurgitate. The water is regurgitated while the jellyfish is hooked up on the papillae.
Apparently, you will see these spines in the mouths and oesophaguses of other turtle species such as loggerheads and green sea turtles. On the Instagram page of Anatomika Science, Helen explains why they exist.
“Sea turtles swallow a lot of seawater while eating. As they eat, their stomach fills up with food and seawater. They then vomit out all the water. The spikes trap food and keep it from coming out. It’s basically a reverse filter.”
It’s nice to have an explanation for them because you see lots of photographs of them on the Internet but not many explanations for their existence.
In the modern age with rampant plastic pollution of the oceans you can see why these turtles are particularly vulnerable to this form of pollution. Bits of plastic bags and whole plastic bags will almost inevitably be ingested but cannot be vomited up because they become impaled on the backward facing spines. They can’t get rid of them.
Internet users ask Google whether sea turtles are dying because of plastic pollution. And the answer courtesy of Google is that, worldwide, scientists estimate that half of all sea turtles have ingested plastic. They also estimate that hundreds of thousands of sea turtles die each year from ocean pollution.
Similar systems of expelling water are found in whales that feed on krill. They have fringed plates hanging in their mouths which are used to filter seawater for food. Fish push water through their gills and only swallow food.
Plastic takes 20 to 500 years to biodegrade; therefore, the plastic pollution present today will still be a hazard to turtles and other marine wildlife over hundreds of years even if theoretically it is all cleared up in an instant. It is said that there are 5 trillion pieces of plastic in our oceans. Plastic pollution is found in the deepest trenches of the ocean and on the surface.
Humankind has known this for a long time now but has done far too little about it. The worst offenders are countries such as India where rivers pour the plastic into the seas. Such an incredibly polluted country, India. Not that the West can complain because America is also a major polluter of the atmosphere being the second worst country in that respect after China.
Humans struggle to change their ways; to use less convenient products but ones which are less polluting to the environment. Habits are hard to change. Convenience is everything for humans. We don’t want the bother and we don’t think about the damage to the environment and the planet. In fact, we don’t want to know about it until it is thrust into our faces by people like Sir David Attenborough.