SIEM REAP – Hermit crabs demonstrate some of nature’s most interesting behavior, a fascinating hunt for homes and the ability to negotiate and share places to live.  Found in coastal areas, hermit crabs are abundant but are threatened by human activities.

Angkor Wildlife and Aquarium (AWA) brings the marine environment inland to the heart of the archaeological and historical city of Angkor Park.

Visitors can enjoy an endless perspective of fresh and saltwater environments with wildlife such as the crabs.

ThmeyThmey Media’s Zul Rorvy met aquarium specialist Khat Sreynoch to understand more about these marine creatures.

Zul Rorvy: With the shells they live in, it is hard for me to tell whether they are truly crabs or lobsters. So, which one are they?

Khat Sreynoch: Yes, they can look tricky. Although hermit crabs appear more similar to crabs, scientifically they are related closer to lobsters with only some physical differences. They have a soft abdomen and curved body to squeeze tightly into empty shells.

They are excellent home hunters. As they grow, hermit crabs need to precisely calculate the weight and size of the empty shell they choose. A good shell allows them to move around easily for food and escape predators.

During the early phase of their growth, hermit crabs spend more time changing shells as their body develops more quickly.

Zul Rorvy: How do they know when to change shells, and what is so interesting about this behavior?

Khat Sreynoch: One of the most fascinating things to observe about hermit crabs is when they change shells. A group of hermit crabs would come together in a queue starting from the bigger ones.

Then they test one another’s size and exchange their shell like a domino following the difference in sizes. The bigger crabs will leave the tighter shells for the smaller crabs and so on.

During the molting process, when crabs need to develop new exoskeletons as they grow, hermit crabs bury themselves deep in the sand for a while for safety.

Older hermit crabs can take months to molt. Another interesting thing is that they can also regenerate lost limbs. Depending on their sizes, they can lay up to tens of thousands of eggs.

Zul Rorvy: Where can we find hermit crabs, and do we have them here in Cambodia’s natural environment?

Khat Sreynoch: Around the world, there are more than 800 species of hermit crab, some can live on land and water but they still rely on the aquatic environment for reproduction.

They are found in deep seas, and in brackish water of mangrove forests. There is also a small number of species which can live in freshwater such as at the island nation of Vanuatu east of Australia.

In Cambodia, we can also find hermit crabs in our coastal provinces such as Kep, Koh Kong, Kampot and Preah Sihanouk. We have none in our freshwater environment. They are omnivores. They can eat seaweed and other fragments of aquatic creatures.

Zul Rorvy: It seems to me that their population is resilient, should we be worried about them?

Khat Sreynoch: According to the International Union for Conservation of Nature, these species are not endangered. However, we should never take their presence in nature for granted. Every animal plays a role in balancing the complex web of ecosystems of which humans are a part.

Although their population remains large, they are also losing their habitats due to human activities. Land reclamation destroys their homes, while pollution makes their water dirty and full of unwanted debris. Global warming also raises sea levels that engulf sandy areas where hermit crabs call home.