The Deadliest for Human - Which sea creatures caused highest number of Human Deaths

Ocean is full of ferocious predators, venomous animals which can kill a human within few minutes. But we only need to worry about those which actually kill people.

This article documented only few animals which are most dangerous to us and caused many fatalities or serious injuries. Sea snakes are not included as they rarely cause any fatality as they are not that aggressive towards human. But, they are deadly, no doubt. One drop of Beaked sea snake venom can kill 3 men and a mature beaked sea snake has enough to kill 39 adults.

And killer whale, which many people think as one of deadliest predator, is not so deadly for us. Study shows that human flesh doesn’t activate their taste buds, means they are not at all interested in killing you unless you are bothering him with a camera crew.

Here are the dangerous creatures which are really deadliest to human.

Stingrays:

These are one of the most common groups of fish responsible for human envenomations; largely because many rays bury themselves on the seafloor and people unintentionally step on them. Stingray venom is generally cardiotoxic and not deadly. In fact, hot water can destroy the venom. The venom composed of the enzymes 5-nucleotidase and phosphodiesterase and the neurotransmitter serotonin. Serotonine

causes severe smooth muscle contract and enzymes causes tissue death. But, if not treated immediately and venom enters abdomen or chest cavity, it causes tissue death in vital organs. Besides, sharp barbs on the spine often cause serious injuries. The sharp tip enters flesh smoothly and then tears every muscle in its way out. So, strike of its spine can cause severe tissue damage, bleeding and even death without using a drop of venom.

Stone fish:

It is considered one of the most venomous fishes. In fact, few people gave it title of most venomous fish. As they look like stone, people often step on them. It has stout dorsal fin spines which inject the venom. It generally delivers neurotoxin which acts on nervous system. A sting from one of these fish can cause severe pain, rapid swelling, tissue death, muscle weakness, temporary paralysis, and in few cases, death.

Pufferfish:

It is actually more venomous than stone fish but it rarely come in contact of human. It  delivers a very powerful neurotoxin known as tedrodotoxin. It has no antivenom. It will inhibit neural transmission leading to weakness, paralysis, respiratory failure, and death.

Cone snail:

This colorful marine snail has the fastest acting venom in the world which kills you in 2 to 3 minutes. And they have more than 100 fatal neurotoxins in their arsenal. They also inject a pain killer along which that venom cocktail. It means would not feel pain when it stings you. And its venom will stop function of nervous system and cause respiratory failure before victim can take any measure. So, don’t pick colorful snails on beach.

Blue ring octopus:

It very small and colorful octopuses also delivers tedrodotoxin like the pufferfish.  But they caused more deaths, around 16. With no antivenom available their sting means death by respiratory and nervous system failure.

Shark:

Sharks are known for their aggressive nature specially the fearsome trio, tiger shark, bull shark and the great white. As they are found in areas where humans enter the water, they had caused many injuries and even fatalities. Till 2014, around 548 fatal shark attacks are recorded and most those include one of these three, specially bull and great white.

Saltwater Crocodile:

It grows upto 20 feet and known for its aggressiveness. They cause 106 deaths only in Australia during 1970 to 2013 time periods. They have most powerful bite, ever measured, even stronger than shark bite. Their jaw shut with 3,700 pounds per square inch or 16,460 newtons of bite force, powerful enough to crush bones.

Box Jellyfish:

It is one of the most venomous animals in the planet. It grow up to 20 cm and the tentacles can grow up to 3 meter. The tentacles have nematocyst cells for venom production. This killer jellyfish delivers a cocktail of neurotoxins, cardiotoxin and tissue killer chemical. Means the victim will feel weakness, severe pain, high blood pressure, and may die from cardiac arrest.

There are almost 60 fatal cases, but real number is much higher.

So, if you ever feel like going to ocean, be alert to avoid contact with one of these killers.

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Feed the Curiosity

How much memory do we have and How memory is stored-retrieved in our brain

How much memory our brain can store or how many gigabyte of space is there in our brain?

The concept of storing data in our brain isn’t like storing data in hard drive at all.

In Hard disk, Data is stored digitally in the form of tiny magnetized regions on the platter where each region represents a bit.

How data is stored in hard- drive

But in our brain data is stored as circuit of neurons.

During memory recall, electricity flows through the neural pathway associated with the memory.

Few scientists claim our brain may have up to 100 billion neurons and each can make upto 1000 links, so 100 billion x 1000 = 100 trillion.

Many say, Neurons can combine with each-other to make very complex circuits which increases the estimation of memory many fold, as high as many petabytes, enough to record TV programs in HD for few hundred years.

But they were quick to admit that all this calculations are way too unreliable.

Our brain can't be compared to any other storage devices:

What we store in hard disk is there in form of 0, 1.

But our memory recreate itself on every recall because our brain stores different data in different places like visual data in visual cortex, memory of smell, sound, touch etc are stored in different parts of brain, amygdale stores emotions etc. So, recalling a whole event caused reassemble of data. That is why our memory changes a little every time we recall.

A memory is stored as collection of scattered fragment and reassembled on recall

For us, remembering means reconstruction of memory from scattered fragments.

You can say Jurassic Park 4 movie is 16 gb. But when u recalling whole movie ur brain recreating it on-the-fly, that’s why it may be little different from real one though u didn’t missed a scene.

Say, u try to recall Jurassic park 3 after that, brain would use many common fragments to recreate it.

So, in your hard drive Jurassic Park 3 and 4 may be 14gb + 16gb, but in your brain those are fragmented data and brain have enough capacity to reconstruct them to a full movie. That is why every time you recall the movie some of the details would be little different or absent.

In 2012, IBM successfully simulate 530 billion neurons and 100 trillion synapses using Blue Gene/Q super computer, still it was 1500 times slower than human brain, ignoring the fact, our brain process much complex inputs and routines.

Brain vs IBM super computer and brain win by miles

Our brain is so efficient that recalling memory is rethinking and reconstructing it on-the-fly from tiny bits and pieces, not lame like just reading data from a disc.

That means our brain can’t be measured in gb or tb.

Forgotten, lost memories have been successfully retrieved through hypnosis which is evident that we normally don’t forget long-term memories.

We don't lose long-time memory, we lose retrieval cues

As our brain is constantly changing with every information and memory, we sometimes lose retrieval cue to some memory.

Watch to understand how our memory works and How memory is stored-retrieved and memory capacity of our brain:

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