He has two claws, one big and one small. When he meets a female he likes, he waves his large claw to chase away other males. He can threaten enemies or woo a mate, all with his one giant claw... In Discovering Mysteries Season 2, Episode 4, the film crew introduces us to the Bowed Fiddler Crab and the many other fascinating creatures who make their home on the mangrove forest mudflats.

Discovering Mysteries Season 2 Episode 4: Fiddler Crabs (Photo: Discovering Mysteries)

In the Dongzhai Harbor Mangrove Forest Nature Reserve, in Hainan, China, the intertidal zone where the sea and land meet is covered by a lush mangrove forest. This is an important habitat for many rare, endangered water birds, as well as an abundance of fish, shrimp, crabs, and shellfish.

At high tide, the Little Egrets rest on elevated perches. When the tide goes out, they descend to the mudflats to wait for tasty treats to appear.

Little Egret (Photo: Discovering Mysteries)

This is a busy spot, with the mudskippers hopping around the mudflat looking for a meal. They propel themselves forward with their well-muscled pectoral fins. The mudskippers don’t get along with their neighbors, the crabs, and force them down under the water.

A Mudskipper confronts a crab (Photo: Discovering Mysteries)

A Sentinel Crab cautiously pokes out his two matchstick shaped eyes. These crabs form the most active community on the mudflat, but as soon as there is the slightest hint of trouble they rush back into their holes.

The more cautious crabs only poke out their eyes while the bolder ones come out with their companions. However, hiding in the water isn’t necessarily safe. When other crabs approach, they sometimes charge out and attack.

A Sentinel Crab (Photo: Discovering Mysteries)

Bowed Fiddler Crabs living in Danzhou Bay move about near their holes which will hide them in case of a predator attack. The holes help keep them alive.

A male Fiddler Crab is cleaning his large claw in preparation to go out. When he sees a female crab he likes, he will wave his claw to chase away other males.

A family of Bowed Fiddler Crabs in Danzhou Bay (Photo: Discovering Mysteries)

The Bowed Fiddler Crab is the most common crab in the mangrove forest. These crabs have eyes that stick straight up into the air, and the males have one small and one giant claw. Female Fiddler Crabs are around the same size as the males, but they have two small claws instead. The male crabs often wave their giant claw, showing off in front of other males or challenging them to a fight. During mating season, they also use it to woo female crabs, while their small claw is only used to scoop mud into their mouths, where they strain out the organic nutrients and spit out the leftover sand. Since the small claw is how they forage for food, the males aren’t as well equipped or able as the females in feeding.

A Bowed Fiddler Crab (Photo: Discovering Mysteries)

Fighting and foraging on the mudflat, these crabs put on quite a show!

Discovering Mysteries Season 2 started being broadcasted worldwide on August 2. The first part of Discovering Mysteries Season 2 focuses on the wetlands and the mangrove forest. Season 2 will have a total of 24 episodes, each running around 4 minutes. This season explores the mangrove forest, the wetlands, Baihualing, and the rainforests of Wuzhishan, as well as Jiaxi and the Exianling nature reserve.

This is Hainan: Discovering Mysteries is a short documentary series that shines a light on Hainan’s ecological and cultural geography. It reveals Hainan’s natural environment, focusing on nature, ecological protection, and scientific research, giving viewers a look inside the natural ecology of the Hainan Free Trade Port, the many plant and animal species native to the island, and the achievements of the national ecological culture pilot zone.

Open the New Hainan App, Hinews, or Nanguo Metropolis Daily, or the Hainan International Communication Network (https://www.hicn.cn/) to watch the fourth episode, Fiddler Crab!

Click the links to see more episodes of Discovering Mysteries:

Discovering Mysteries Season 2 Collection

Discovering Mysteries Season 1 Collection 

Producers: Guo Zhimin, Wu Bin, Han Chaoguang

Production Supervisor: Luo Jianli

Executive Supervisors: Hu Xufa, Lin Ying , Yu Weihui, Ao Kun

Filmmaker / Director: Li Xiaogang

Writers: Mi Hongxu, Li Xiaogang

Videography: Xu Wei, Liu Sunmou, Mi Hongshu, Zheng Ziyu, Li Xiaogang

Editors: Li Xiaogang, Xu Wei

Special Videography: Feng Erhui, Chen Zhengping, Luo Lixiang, Lü Shiyang

Narrator: Liu Yang

Print Media Design: Gong Yuming

Translator：Nicki Johnson

Jointly Produced by: The Hainan Hainan Tropical Rainforest National Park Management Office and the Hainan Wild Plant & Animal Protection Management Office

With special thanks to: Hainan Pingtouge Culture Media Co. Ltd.

Jointly Produced by: New Hainan APP, Hainan International Media Center and Hinews

A production of: Nanguo Metropolis Daily