Shell survivors

There is only one option for those who want to spot this cute creature up close-you must climb mountains and trek through the jungle.

But sadly, your chances are decreasing almost daily as this creature is on the verge of extinction, sharing the same plight as other species of wild animals whose habitats are being encroached on by human beings and whose lives are in great jeopardy. Known among Northeastern people as puu isan (literally Isan crab), the mountain crab belongs to the species of Ranguna (Ranguna) phuluangensis. Although it lives in the deep, inaccessible jungle, its life is insecure. Over the past decades, it has fallen prey to local villagers who have settled near the mountains and cook it for food. It is widely held that the mountain crab has soft, sweet, aromatic flesh when baked or steamed. Its shell is also rich in calcium which is good for bones, nails and teeth. Hunting the mountain crab has taken its toll on the population. And the situation is felt throughout Sakon Nakhon's mountain ranges, including the famous Phun Pan mountain range.

In an effort to restore the number of mountain crabs in the Northeastern mountainous forests, Kosit Sriphuthorn, a biologist with the Sakon Nakhon Agricultural Research and Training Centre, Rajamangala Institute, is trying hard to save this rare species. And part of his achievement is breeding the mountain crab in captivity.

"There are many tasks ahead. But I'm ready. It will be a tragic loss if the species becomes extinct. At least I can use my knowledge to serve my community and try to correct the situation," said Kosit, while gripping a mean-looking specimen.

It all started last year when Kosit accidentally stumbled on the species on a trip to survey and collect medicinal herbs thriving in one of the jungles in Waritchaphum district, Sakon Nakhon province. The crustaceans, however, were found not in their natural habitat, but in the cooking pots of local villagers.

"Aside from fish, mountain crabs serve as a staple food for villagers who live near the mountain. The crabs have long found their way into the local cuisine. Villagers bake and steam them for food," said Kosit. Even the crab's shell is edible. Rich in calcium, the shell, pounded in a mortar with the meat, is cooked with ingredients like sliced lemon grass, garlic, chilli and shallots and then decocted. Popular among Northeastern people, this recipe is known as u-ka-puu.

Pinning his hope on the villagers themselves to return the mountain crab to the hilly areas, Kosit chose the simplest way to revise the situation-talking with the local hunters. "I asked them not to catch the crabs during their egg-laying season. And the young ones should not be hunted as well. To sustain their food source, villagers must not exploit it but wisely manage it with their natural resources," said Kosit.

His initial efforts were fruitless, however; villagers turned deaf ears.

"Only a few listened to me. The others said they needed more food to fill their kids' stomachs. And they can't afford to look elsewhere for food. I was not angry at them but tried to explain that looking after the crab now means a long-term source of food," said Kosit.

In an attempt to increase the population of the mountain crab and breed it in captivity, Kosit, with no knowledge about the species, approached Asst Prof Chalermvilai Chuensri, a lecturer at Kasetsart University's Faculty of Fisheries who is an expert on the freshwater crabs of Thailand, for the information he needed. "Information about the freshwater crabs of Thailand is so scarce. Textbooks on the topic are unavailable. So I needed to start my research from scratch. Trial-and-error was my best teacher," said Kosit.

Two villagers who know the mountain trails quite well were hired as Kosit's guides. The team made their way deep into the forests in Waritchaphum district in search of information about the mountain crabs some six months ago.

The expedition was very tough, said Kosit. The exploration team trekked across two mountains before safely arriving at their destination-a mountain brook where the crabs forage for food.

"I searched every nook and cranny of the mountainous jungles and waterfalls looking for the creatures inside rocky crevices or holes. We had to be eagle-eyed," said Kosit.

"I spotted only 20 crabs. Villagers told me that in the old days the mountain brooks would be teeming with the mountain crabs and they could catch them more easily," said the biologist.

"The local guides taught me how to search for the crabs and how to grip them carefully. The creatures gave me many big pinches, however. If we made the water muddy we couldn't see the crabs. Our expedition days were full of joy and laughter. I experienced many new things in the natural world," Kosit recalled.

Day in, day out, Kosit ventured into the forest to glean information about the crab's eating habits, natural habitat, growth rates, mating rituals and habits, egg-laying behaviour, and egg clustering. And this data was of tremendous benefit in starting the breeding project.

According to Kosit, the mountain crab grows to a width of about 70 millimetres or so and its weight is about 65 grammes. It has flesh similar to sea crabs. Its body is a greyish-violet shade. Mountain waterfalls and forests serve as its natural habitats, and it feeds on animal carcasses, parts of rotten trees, insects, young fish and other aquatic animals. The mountain crab's mating season lasts from October to January, and January is its egg-laying month. On average, one female crab lays many eggs-70 roe or so. Yet even blessed with such abundance the mountain crab is under threat.

On a long trip last August, Kosit made his way to Phu Tham Phra in Tadphuwongse district in Sakon Nakhon. This time Kosit brought some 20 mountain crabs (10 female and 10 male) back to his laboratory at the Sakon Nakhon Agricultural Research and Training Centre, Rajamangala Institute (Sakon Nakhon campus) for further study. Only adult crabs were singled out. Two cement tanks were built to house the crabs. Kosit designed an ecological system inside the tanks to mirror their natural environment. "The whole tract is divided into two zones, wet and dry areas. Clay is put at the bottom of the tank. Small and big pebbles are scattered here and there. PVC pipes serve as a refuge where they can hide themselves. Aquatic plants keep the habitat fresh and verdant. The water is changed from time to time," explained the biologist.

One tank can accommodate 10 crabs (five male and five female). Those of equal size are grouped together.

Kosit works from dawn till dusk. "I come to my laboratory early in the morning to tend to the crabs. I take note of their behaviour. They are adjusting themselves to a new environment and they need extra care," he said. "And I come back once again at night to feed them with young fish. Then I can go home," he added.

Despite such attentive care, Kosit was disappointed with the initial results. "Some died. Some refused to eat. I felt discouraged, but I had to continue my research," he said. Eventually, his efforts paid off. Kosit successfully began breeding the crabs in captivity. So far, there are 30 crabs in his care. Though successful to a certain degree, Kosit said his research is endless. His next challenge is to tend to the young crabs to help them to survive. "The hardest work is to nurture the young crabs because they are vulnerable. I have tried many ways to save them all. They are kept in the tank with running water, to enhance oxygen and purify the water," he explained. If completely successful, Kosit will hand over all his breeding know-how to local villagers. Apart from the mountain crab, Kosit also conducted thorough research on other species of freshwater crabs such as the forest crab, the black rice crab and the creek crab. Currently, Kosit is working on a scientific experiment to breed the three freshwater crabs in captivity. "We Northeastern people live far from the sea and must rely on expensive and often stale seafood. The freshwater crab culture is not widespread yet. Only the pickled crab used to prepare som tam (papaya salad) has commercial value," said Kosit.

"Some kinds of freshwater crabs such as mountain and forest crabs are bigger and have flesh like their cousins, the sea crabs. Freshwater crabs also have a higher fat content," he added. Different parts of freshwater crabs, he said, have different curative powers, according to traditional beliefs. After baking, the crab shell produces a a medicinal liquor with tonic effects believed to enrich the calcium supply to the body. Another tonic is derived from pounding a whole fresh crab in a mortar, then using it to detoxify the blood. The crab shell is rich in chitin, a substance which helps to reduce cholesterol and triglyceride levels in the blood.

Kosit has further plans for the crustaceans. "To make the delicious local dishes known to city gourmets, I plan to produce canned u-ka-puu. I am so happy to have a chance to take up new challenges as well as to protect the local natural resources," he added.