(VAN) Turning off his head flashlight, Dr. Pham Dinh Sac quickly flipped the ultraviolet light switch. A blind scorpion glowed in the UV light, clearly visible in the pitch-black cave.
Picking up his backpack, Dr. Sac walked from the boat on the Con River to the dock at the foot of Phong Nha cave. On that day, his destination was not the usual large cave but Tien Son - a smaller one high above, where he and his colleagues discovered a blind scorpion species over ten years ago.
Dr. Pham Dinh Sac wore neat picnic clothes. He tightened the strap of his white helmet and quickly walked up the stone steps. With a slim and elegant figure, he quickly conquered the 600 steps up to the entrance of Tien Son cave, which many young people could not follow.
As a careful scientist, he took out his backpack to recheck his belongings before entering the cave. He made sure to have three handheld and head-mounted flashlights with different brightness levels, an ultraviolet lamp, spare batteries and a plastic box.
Inside the plastic box were a thermometer, a hygrometer, and a few sample jars. He said: “When entering the cave, you must always check the temperature and humidity. Those factors determine the living environment of the animals here, so we have to measure and record very specifically.”
In addition, Mr. Sac kept an item very carefully: a picket pin made from precious alloy. This doctor said the unique feature of this pint is that it can pick up insects and small animals very firmly but without hurting or damaging the specimen. Another point is that it is expensive, so he must store it carefully.
When he was sure he had enough gear, the Deputy Director of the Natural Sciences Research Center (Vietnam Museum of Nature) entered the cave, slowly as if not wanting to miss any details.
His research trip not only focused on scorpions but also on all the invertebrates in the cave. Therefore, every rock crevice and hole in the ground with signs of life attracted his attention.
After a 100-meter journey along a steep and narrow path, he shone light dozens of times to observe all kinds of spider webs. He caught spiders and put them in jars. When the cave was flat and wider, Mr. Sac whispered: “We’ll probably see the scorpion soon.”
Indeed, just a few minutes later, a few meters away from where he whispered, a small creature the size of an index finger hid in the million-year-old rock floor of the cave. Turning off the flashlight on his head, Dr. Pham Dinh Sac quickly flipped the ultraviolet light switch. The blind scorpion now glowed, clearly visible in the pitch-black cave.
Without hesitation, Mr. Sac quickly pulled out the metal pint, clamped it horizontally on the scorpion’s body, observed it momentarily, put it in a sample bottle, and carefully stored it in a plastic box before putting it in his backpack.
This species in Phong Nha - Ke Bang caves is called a “blind scorpion” because it has no eyes, while regular scorpions have between 6 and 12 eyes. Over centuries, their eyes have disappeared to adapt to the living conditions in these unique caves. Scientifically, they belong to the genus Vietbocap (Vietnamese scorpion), discovered and announced in 2010. The specific name is Vietbocap canhi, a species of the Pseudochactidae family.
Another characteristic is that because they live in caves and have few natural enemies, this special animal is no longer poisonous, unlike its counterparts in forests or deserts.
According to Dr. Pham Dinh Sac, for ten years between 2010 and 2020, he and his colleagues searched, discovered and announced a new scorpion breed called Vietbocap - a new subgenus Vietscorpiops - and nine new scorpion species for scientists.
“These new genera, subgenres and species of scorpions have been described and published in eight scientific articles in prestigious international journals on the ISI list, including two articles in Zookeys Magazine (SCI-E) and six articles in Comptes Rendus Biologies (SCI) Magazine,” Mr. Pham Dinh Sac shares with us in Tien Son cave, Phong Nha - Ke Bang National Park.
Accordingly, the discovery and announcement of a new scorpion variety (the scientific name is Vietbocap, and the Vietnamese name is Vietnam Scorpion) made a significant scientific breakthrough. This is a unique, rare breed of scorpion that lives specifically in cave environments.
Of the nine species discovered above, eight live in cave environments. These are animals that live specifically in caves (troglobitic). They evolved to adapt to cave environments: no eyes or minimized eyes, light body color, and long legs and arms. Another feature is that the caves where scorpions are found are all isolated from each other.
Regarding species conservation and sustainable development of biodiversity in Vietnam, scorpions are a group of invertebrates that are significant in science and real life.
Scorpion venom is a potential source of medicinal raw materials to produce food to protect human health. Scientists have found some active ingredients in the venom of some scorpion species that can identify and destroy cancer cells but do not affect healthy cells.
For example, in Cuba, scientists have used some active ingredients from blue scorpion venom to successfully produce a functional food (Vidatox) and treat breast cancer. However, scorpion research is still a new research direction in Vietnam and our country. There are currently 34 species of scorpions recorded.
Among nine scorpion species discovered and announced from 2010 to 2020, eight species were found in caves (each species is only distributed in one cave). Caves are isolated ecosystems - wholly isolated from the outside environment - and the caves where scorpions are found are also isolated from each other.
According to Howarth (2003), cave-specific animals are identified as endemic to the region. Thus, the eight new scorpion species distributed to cave science are endemic species across Vietnam and to the cave where scorpions are found. This discovery not only enhances the value of Vietnam’s biodiversity but is also very meaningful in biodiversity conservation.
Specifically, the cave scorpions (eight species) only live in one cave, have a small population size, and a very narrow distribution area. Besides, scorpions in caves are very sensitive to changes in their environment. They live in a stable environment (zero light intensity, stable temperature and humidity).
Caves affected by humans (such as tourism development) will reduce scorpion populations and they may disappear if not preserved.
Currently, regarding the conservation status of two scorpion species, Euscorpiops cavernicola (Hua Ma cave, Bac Kan) and Vietbocap thienduongensis (Thien Duong cave, Quang Binh), the research shows that according to IUCN criteria, the aforementioned species can be proposed as critically endangered (CE) and need to be included in the Red Book of Vietnam and IUCN.
From a scientific perspective, Dr. Pham Dinh Sac said that the discovery of new scorpion species for science is very meaningful for species conservation and the sustainable development of Vietnam’s biodiversity.
“The discovery of new scorpion species for science not only enhances biodiversity value but also clearly indicates the endemic value and current status of the species in species conservation; or special and rare species in the conservation of genetic resources; as well as in the conservation of ecosystems (cave),” Mr. Pham Dinh Sac analyzed.
The discoveries of new scorpion species for science show that caves in Vietnam have high biodiversity value, with many endemic species. Vietnam owns one of the top cave systems in the world.
“This sends a clear message to managers: Protecting the value of cave biodiversity while developing tourism to serve local socio-economic improvement is necessary. Besides, the production of scorpion venom for medicinal use and pharmacy must comply with the principles of sustainable use and development of biological resources in Vietnam,” the scorpion expert from the Vietnam Museum of Nature affirmed.
In 21 caves in the core area of Phong Nha - Ke Bang National Park and the expanded area, surveys have shown that the main differences in the assemblage of invertebrate fauna are impressive in species diversity, number of individuals, and biodiversity value (indicated by species new to science) between cave groups.
Group 1 consists of cave 17, cave 18, Tien Son cave, Ba Da cave, Cau Chay cave, Ruc cave, and Mu Nganh cave, with low number of individuals, species as well as biodiversity value. Caves belonging to this group are small (limited length and width). Besides, the structure of the caves in this group is simple, with few nooks and crannies. These characteristics are unfavorable conditions for the emergence, development and survival of invertebrates in caves.
Group 2 consists of Tuong cave, Lo Do cave, Sot cave, cave 11, Dark cave, Nui Doi cave, E cave, and E shallow cave. These caves have an average population size.
Group 3 consists of Phong Nha cave, Thien Duong cave, Son Doong back cave, Cha Ra cave, Da Voi cave, and Mo O cave, which are completely different from Group 1 caves. These caves have higher biodiversity than other caves. The caves belong to group 3, large in both length and width, and have complex structures with many nooks and crannies. These are favorable characteristics for the survival and development of invertebrates in caves.
Previous surveys by Associate Professor. Dr. Pham Dinh Sac shows that at the cave invertebrate fauna in Phong Nha - Ke Bang National Park and the expanded area, there are 730 mature individuals, including 83 species, 55 families, 24 orders, and seven invertebrate classes. Among these, 48 species live in cave environments, and 25 species could be new to science.
Of the 83 recorded invertebrate species, 35 belong to the transient group - species commonly found outside caves. The remaining 48 species (accounting for 57.83%) have particular adaptations for surviving in caves.
Currently, several caves with high biodiversity value such as Tien Son cave, Thien Duong cave, Dark cave, Phong Nha cave have developed tourist activities. Therefore, it is crucial to develop tourism while still preserving biodiversity values.
For example, caves are home to bat and bird species. These animals form the preferred excreta of some cave invertebrates. When humans scream or yell in caves, they affect the natural aggregation of bats and birds.
These animals provide an essential source of energy for cave invertebrates. A change in bat and bird populations would cause profound changes in the assemblage of cave fauna.
In addition, some tourists do not follow the rules set out by the National Park regarding eating, drinking and smoking in caves. They litter in the cave, leaving behind drinking bottles, juice boxes, beer cans, lucky money, clothes, eggshells, peanut shells, etc. These things attract pests into the cave, affecting the animals living in the cave.
Surveys have found that rats are present in caves with developed tourism activities. Apparently they live in caves, which is a big problem. Trash cans placed in caves are also a food source for harmful species and must be moved outside the cave.
Furthermore, the current lighting system in some tourist caves is not conducive to creating suitable habitats for cave fauna. Constant sources of artificial light harm the bat and bird populations in the cave. The current lighting system creates a colorful world that stimulates visitors to the cave, further increasing the noise level, which affects the bat and bird populations in the cave.
Artificial lighting is another problem that creates inappropriate illumination in the cave. The growth of algae, moss, or ferns in caves will increase artificial food sources. This problem can be solved by reducing lighting time as well as the type of lamp used.
Invertebrates living in caves are not only diverse in species and individuals but are also very special in morphology and highly endemic.
Due to the isolation from the outside environment, along with differences in light regimes and humidity, these species have special adaptations for surviving in caves. Therefore, many new taxa have been recorded in caves all over the world.
However, many invertebrate species are threatened by human impacts and are at risk of distinction if not preserved. Over 300 large and small caves have been discovered in the Phong Nha - Ke Bang area. These “living natural museums” are home to many native and very unique invertebrate species but have not been researched thoroughly.
The discovery and description of new taxa for science justifies the endemic nature of the invertebrate fauna in the region. More scientific activities are urgent and necessary to shed light on the imminent value of biodiversity in Phong Nha - Ke Bang area.
