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Biosphere in West Bengal: The Tiger Needs the Crab: Bengal Tiger; Fiddler Crab; Sundarban National Park

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Ann has a varied interest in nature and wildlife, likes to share information and experiences she regards as interesting and/or important.

Sundarban National Park in West Bengal


Where and What is the Sundarban?

This article was inspired by a BBC Two television programme. It was episode 4 of 4 from the series 'Secrets of the Living Planet', called 'Waterworlds', presented by Chris Packham, one of our best wildlife presenters. It drew me in and enthralled me.

The Sundarban National Park is also a Tiger Reserve and a Biosphere Reserve, situated in West Bengal, India. Sundarban is Bengali for ‘beautiful forest’. This national park is part of the Sundarbans on the Ganges Delta, adjacent to the Sundarban Reserve Forest in Bangladesh.

The delta is densely covered by mangroves, indeed it holds the largest mangrove forest in the world. It is also one of the largest reserves for the Bengal Tiger. Home to a variety of wildlife, the Sundarban National Park is a UNESCO World Heritage Site.

Visit the Mangrove Forest

Imagine, if you will, that you are on the edge of mangrove and mud, near the river. You glimpse into the dense forest.

Bengal Tiger

The Tiger; Bengal stripes creep diagonally like a cut-and-staggered picture, flashing orange between the mangroves.

He hunts close to the mud banks of the Ganges, even picking off the occasional human. He rests on the cool mud. He shimmers then fades into mangrove density.

Tiger, Mangrove and Crab

Bengal Tiger on the mud banks in the Sundarban Reserve

Bengal Tiger on the mud banks in the Sundarban Reserve

Stop me if you Dare!

Stop me if you Dare!

Mangrove Forest

The forest blankets the Ganges Delta. Thick roots reach into the mud, draw nourishment from it, form vast interlocking networks as they spread ever outward.

Their snorkels, mini skyscrapers aiming heaven-ward from the mud, enable them to breathe at high tide.

The mangroves cleanse the Ganges whose clear waters flow on into the sea, a transparent viewfinder exhibiting coral, exotic fish and incomprehensible beauty.

Fiddler Crab

The Fiddler; unbalanced claws play his music as he feeds in the mud, creating burrows, cleansing and tidying as he goes. He fiddles all day, rejecting toxins, bundling them up, leaving piles of rubbish outside his burrow.

An orchestra of crustaceans shares the mud, occupying bi-ways of burrows amid mud-roots of mangroves.

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The Fiddler ensures the Mangroves have nourishment for their roots, thereby protecting the forest. The Mangroves cleanse the river which merges into the sea, whilst sheltering wildlife including the Tiger, simultaneously providing his prey.


Connections, cross-connections and interaction between hundreds of organisms and nutrients sustain this wondrous biosphere.

The term ‘ecology of fear’ applies here. Other wildlife use the relative safety of the mangrove to hide from the tiger. The tiger uses it for shelter and sustenance by hunting. The wildlife, therefore, do not expose themselves to certain death by traversing the mud banks so the crab remains relatively safe to go about its daily housework, cleaning up the mud.

Without the crab, the mangroves would perish and so it is an essential contributor to this invaluable biosphere.

Thus the strong, top-of-the-chain Tiger needs the Crab, the menial worker minding his own business.

How cool is that?

Diagram of Fiddler Crab

Fiddler Crab Facts

  • They are dimorphic (have two distinct forms),
  • the males have one large and one small front claw, the females two small claws,
  • the males use their small claw for feeding and
  • they use the large one to attract females for mating, to threaten other males and as a weapon when fighting.
  • They are sometimes known as the ‘calling crab’, as the waving large claw looks as though it's beckoning,
  • they are found on sea beaches, brackish inter-tidal mud flats, lagoons and swamps,
  • they shed their shells as they grow, replacing any damaged legs or claws at the same time.
  • They exhibit a ‘constant circadian rhythm’ under controlled laboratory conditions, mimicking the ebb and flow of the tide.
  • They turn dark in the day and light in the dark.
  • They communicate by waving and gesturing with the larger claw,
  • the smaller is used for feeding so
  • it appears to be playing the larger claw like a violin, or fiddle, hence the name of Fiddler Crab.

The male crab's smaller claw picks up a chunk of sediment from the ground and brings it to the mouth, where its contents are sifted through. After anything edible is salvaged, whether it be algae, microbes, fungus or other decaying detritus, the sediment is replaced in the form of a little ball.

The Fiddler is a detritivore, that is it sifts through the mud to extract its food.

Sediment balls near the entrance to a burrow indicate occupation. So the feeding habits of fiddler crabs play a vital role in the preservation of wetland environments. As they sift through the sands, they aerate the substrate and prevent anaerobic conditions.

Bengal Tiger Bumph

  • Found mostly in India, the Bengal Tiger can also be seen in Bangladesh, Nepal, Bhutan, China and Myanmar,
  • it is a carnivore,
  • using its unique stripe pattern as camouflage and
  • focussing its hunting on deer-sized animals such as horses, goats and moose but
  • will also try to take down larger animals, such as elephants and bears.
  • It is the most numerous of all tiger subspecies with more than 2,500 left in the wild.
  • It’s the national animal of both India and Bangladesh and
  • is an endangered species.
  • Also referred to as the royal Bengal tiger, it has developed a ‘unique characteristic’ of swimming in the saline waters and
  • has a tendency to attack and eat humans.
  • India’s tiger reserves, created in the 1970s, helped to stabilise numbers, but
  • poaching has again put the Bengal at risk.

Mangrove Roots and 'Snorkels'

More about Mangroves

  • Mangroves live, at is were, with one foot on land and one in the sea,
  • being ‘botanical amphibians’ which occupy a zone of desiccating heat, choking mud, and salt levels that would kill an ordinary plant within hours.
  • The mangroves of the forest are among the most productive and biologically complex eco-systems on Earth.
  • Birds roost in the canopy, shellfish attach themselves to the roots, and snakes and crocodiles come to hunt.
  • Mangroves provide nursery grounds for fish,
  • a food source for monkeys, deer, tree-climbing crabs, kangaroos and
  • a nectar source for bats and honeybees.
  • Those of the Sundarbans are increasingly threatened by sea level rise as a result of climate change.

Mangrove, Mud-bank and River

Mangroves by the water, looking into a small creek

Mangroves by the water, looking into a small creek

Protecting the Planet

It seems that the mangroves contribute much in themselves to planet conservation but they in turn need protecting. Throughout the world, some have been destroyed for shrimp farming, industrial building and deforestation. One fifth of the world's mangrove ecosystems have been lost since 1980.

The mangroves not only protect the biosphere but have acted as a buffer against the elements, such as tsunami, cyclones, storm surge, erosion and such like. One set of villagers planted 80,244 saplings to get into the Guinness Book of World Records, creating a kilometre-wide belt of trees. When a tsunami struck, even though much of the land around was flooded, the village itself fared much better.

Apart from the practical rôle the plant plays, the sheer beauty justifies its existence, with the array of flora and fauna it sustains worthy of anyone’s attention. Who would not want to preserve such a place? Who can afford not to do so?

Do we lose the Bengal Tiger and other endangered species or do we make a real effort to safeguard its environment? It’s not the appeal of such an animal that is of paramount importance, it’s the survival of our planet.

The Tiger needs the Crab, the biosphere needs the Mangroves, the planet needs ecosystems to support it. We need them all to sustain life.


Protecting the Environment

© 2017 Ann Carr


Ann Carr (author) from SW England on February 18, 2018:

Thank you for reading and for your comment.


Robin Carretti from Hightstown on February 17, 2018:

I love tigers so many breeds they are so distinct they should all be taken better care of.This Planet we live in is so unsettling too many things are going wrong but its good to know the animals of our nature keep us strong

Ann Carr (author) from SW England on August 11, 2017:

Indeed, Claire. Wherever we go there is so much interaction for survival; that's why we mess it up so easily, sadly.

Thanks for another visit today!


Claire-louise on August 11, 2017:

Wow, I did not realise the complexity of the biodiversity!

Ann Carr (author) from SW England on August 03, 2017:

Yes, I would love to visit the park. I think that would involve more of the mangroves themselves rather than the actual creatures which remain quite elusive. Those who get to travel along the river with camera crews are more privileged I think. It is so fascinating though, isn't it?

Thanks for popping by, Jo!


Jo Miller from Tennessee on August 03, 2017:

Wonderful article. As others have said, it is probably better if we humans stay out of the way of these creatures, but, I can't help it: when I read about such fascinating things, I always want to go see them first hand. I would love to visit this national park.

Ann Carr (author) from SW England on August 01, 2017:

Thanks for coming back, Eric. You're right; without the one, the other would not survive, at least not happily. Your insights are invaluable and so are your support and friendship.

Have a great week, Eric!


Eric Dierker from Spring Valley, CA. U.S.A. on July 31, 2017:

You just reminded me of this article as you commented on one of mine. This beautiful notion of "interneed" is so fascinating. My brother wrote me once, after I apologized for being a bad younger brother, he said "Eric, there are no "good" "brothers" or "bad", we all have what we have and we are just brothers. Each has it's place.

Ann Carr (author) from SW England on July 30, 2017:

Thanks for your input S Maree. I totally agree with you that 'tourists' shouldn't be encouraged to go to these places and that it's important for scientists and those who seek the specific knowledge, to do such research.

Giving the world an update on these environments is essential for us to appreciate what is there and why it is important to care. As you say, it's responsibly collected data and sympathetically introduced to the viewer by an experienced team who don't disturb any of the creatures.

I appreciate you stopping by and telling your story. I suppose many of us had pets which we didn't understand properly but these days ignorance is no excuse so thankfully it's generally no longer done. We had some terrapins brought back by my cousins from Malta. They were delightful but all died within about 6 months. Very sad.

Thanks for your encouragement and have a great weekend!


S Maree on July 29, 2017:

As a child, I had a fiddler crab in an aquarium. We received no instructions on care and the poor thing died. I have since decided it serves no good purpose to make pets of wild things, crabs or tigers, or to disturb their turf.

While it is good for professional naturalists to visit endangered natural sites with the view of helping to preserve them for the resident flora and fauna, I am concerned that too many people want to go to such places just out of curiosity. We must reduce our footprints from such areas. Please, if at all possible, leave these poor creatures alone. Let's just study and appreciate responsibly collected data, and help keep these natural areas as intact as possible.

Don't stop, Ann. Tell it like it is!

Ann Carr (author) from SW England on July 28, 2017:

Hi Mike! Thanks for your comments. Yes we do mess it up don't we! When will we ever learn?

Glad you enjoyed this.


Ann Carr (author) from SW England on July 28, 2017:

Thanks, Dora! Not sure that I would either! I appreciate your kind comments.


mckbirdbks from Emerald Wells, Just off the crossroads,Texas on July 28, 2017:

Hello Ann - I enjoyed this excursion. Glad that inspiration found you for you to share. Natire is the greatest gift, and as typical humans tend to get in and mess things up.

Dora Weithers from The Caribbean on July 28, 2017:

I know that I don't want to see the "Bengal stripes creep[ing] diagonally like a cut-and-staggered picture, flashing orange between the mangroves" but your description is appealing. Very informative and interesting.

Ann Carr (author) from SW England on July 28, 2017:

Thanks, Linda. I had to use others' photos for a change but luckily found some good ones. Wikipedia usually comes up trumps!

I'm so glad I just happened to find the programme by chance. Chris Packham is one of our best wildlife presenters and seems to go to the most exotic and fascinating places. There is a whole series covering different environments, 'Secrets of our Living Planet'.

Good to see you today, Linda!


Linda Crampton from British Columbia, Canada on July 27, 2017:

This is very interesting, Ann. Thank you for sharing the information and for writing about an important topic. The photos are great, too.

Ann Carr (author) from SW England on July 27, 2017:

Thanks for the great comment, Jackie, and for voting! I'd love to visit this place too but it would be so difficult to see all those marvellous creatures.


Jackie Lynnley from the beautiful south on July 27, 2017:

I would love to visit but learning about this in any form is still very rewarding. Thank you for being that source!

I voted!

Ann Carr (author) from SW England on July 27, 2017:

Thank you, whonu! Yes, it's one big wonderful balanced system which we should be careful not to upset; unfortunately, we often do. Thanks for stopping by today.


whonunuwho from United States on July 27, 2017:

Nice and interesting work my friend. All of nature is so interrelated and dependent upon each organism to maintain life on this planet. Well done and many blessings. whonu

Ann Carr (author) from SW England on July 27, 2017:

Hello bill! I hadn't heard of it either, until I saw the amazing programme on tv. It was the interaction of it all that was so enthralling.

Good to see you today.

Enjoy a thrilling Thursday too!

Ann :)

Bill Holland from Olympia, WA on July 27, 2017:

There is a big world out there I know nothing about. Thank goodness for articles like this one, Ann, so I can appear to know more than I do. :) Great information! Never heard of this National Park....thank you for compiling it all for those of us who never leave their urban farm.

Have a Thoroughly Tremendous Thursday!


Ann Carr (author) from SW England on July 27, 2017:

Hi Flourish! Thank you very much. Wouldn't it be great if we could do that?! These adaptions of nature are mind-blowing.

Enjoy the rest of your week!


FlourishAnyway from USA on July 26, 2017:

I love the connectedness of this. I learned so much, and it was a joy to both read and look at. It would be nice if we could regenerate any injured or missing legs like this crab.

Ann Carr (author) from SW England on July 26, 2017:

Thank you, Eric, for your kind words and appreciation. Also for your valuable input. It's true that there are amazing creatures everywhere; nature never ceases to invoke wonder. What a great world we live in, despite the cons!


Eric Dierker from Spring Valley, CA. U.S.A. on July 26, 2017:

How cool is that!? We are all about creatures around here from Aphids to Shamu. We have been having some arguments about Bengal vs. Siberian -- who wins? We decided the white tiger because she must fight harder to survive.

They caught some poachers with a Bengal inside Vietnam so we think they stretch that far.

Don't even get me started on the Mangroves. Animals that can do fresh or seawater! Wow! Dry times and wet. So exciting. Thank you for your great work here. It is appreciated by us.

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