Today on the planet freshwater is a very limited resource. Freshwater constitutes less than 3% of all water on earth, and the majority of the world's freshwater is inaccessible to humans.
Today let's learn about an amphibian that is extremely sensitive to pollution and can be encountered only in these wild freshwater streams.
They are Giant Japanese Salamanders (Andrias japonicus), the second-largest Salamander in the world. These Japanese Giant Salamanders are native to rivers in southwestern Japan.
In Japanese, they are called Ōsanshōuo, which means Giant pepper fish.
These Giant Japanese Salamanders are aquatic and nocturnal, usually found camouflaged against the bottoms of streams and rivers being active at night.
As the range of this species is severely fragmented and listed as Near Threatened, The Japanese Agency for Cultural Affairs has protected the Japanese Giant Salamander as a special natural monument since 1952 due to its cultural and educational importance.
Do you know in the species of Salamanders of the Cryptobranchidae family, there are only five known members? You can also learn about other family members, such as the Chinese giant Salamander and hellbender, in addition to the facts about the Japanese Giant Salamander.
Japanese Giant Salamander Interesting Facts
What type of animal is a Japanese giant salamander?
As the name intimates, Andrias japonicus are Giant Salamanders with lizard-like appearances, thin bodies, blunt snouts, small limbs stretching perpendicular to the body, and a tail in both larvae and adults. They are one among about 700 salamander species found worldwide.
What class of animal does a Japanese giant salamander belong to?
Japanese Giant Salamanders (Andrias japonicus) are from the Amphibia class, along with frogs and toads, and caecilians.
How many Japanese giant salamanders are there in the world?
Although the exact number of Japanese Giant Salamanders (Andrias japonicus) is unknown, it is witnessed that their numbers are declining due to their habitat of crystal clear waterways and natural biodiversity.
Where does a Japanese giant salamander live?
As the name itself says, the Japanese Giant Salamander (Andrias japonicus) is the natural habitat of Japan. They can be found in western Honshu Island, the northern region of Kyushu Island, and Shikoku Island of Japan.
What is a Japanese giant salamander's habitat?
These Japanese Giant Salamanders live in and around the Japanese islands' cold, swift mountain streams. They are restricted to flowing water where oxygen is abundant due to their large size and lack of gills facilitating their aquatic lifestyle. Typically the base of these rivers is covered with rocks or gravel where they hide during the day.
Who do Japanese giant salamanders live with?
These Japanese Giant Salamanders live along with other Salamanders, are less sedative are usually found under rocks during the daytime, and are active at night.
How long does a Japanese giant salamander live?
If humans do not hunt these Giant Japanese Salamanders or cause any habitat damage by pollution, they can survive for around 50-70 years.
How do they reproduce?
During the breeding season from August to September, both males and female species migrate to underwater nest sites. These nests have 39-59 in (99.1-150 cm) long burrows into or near the river bank and have a single entrance opening underwater called dens.
The dominant male in a territory will occupy the den and guard a den known as a den master. Females enter the den and spawn with the male, and lay about 400-600 eggs.
Females reach the nests several times and lay their eggs in the cavity, where the males fertilize them.
Larvae emerge from the fertilized eggs after the incubation period which ranges from 40-60 days. The male guards the nest for several months until the juvenile Giant Japanese Salamanders leave on their own.
What is their conservation status?
The main threat for Japanese Giant Salamanders is humans, as these amphibians are hunted for food and medical purposes. Japanese Giant Salamanders are also threatened by habitat loss due to pollution, construction of dams, weirs, and more.
As a result, a continuing decline is observed in these species making their status ‘Near Threatened’, as stated by the International Union for Conservation of Nature, IUCN.
These species are protected by law for hunting. Due to their cultural and educational importance, the Japanese Agency for Cultural Affairs has federally protected the Japanese Giant Salamander as a unique natural monument since 1952.
Japanese Giant Salamander Fun Facts
What do Japanese giant salamanders look like?
The Japanese Giant Salamander (Andrias japonicus) is known as the second-largest amphibian. It is covered with brown and black mottled skin, which provides camouflage with the bases of streams and rivers.
It has a long and broad tail with two pairs of tiny legs. Its mouth can open to the width of its body and stretches across the width of its head.
It has small eyes without eyelids and got poor eyesight. Gas exchange happens over the epidermis. The wrinkles over their warty epidermis increase overall body surface area, assisting in exchanging carbon dioxide and oxygen with the water.
In addition, capillaries on the skin's surface facilitate the easy diffusion of gases. Japanese Salamanders have a slow metabolism that allows them to survive for weeks without eating.
The Giant Japanese Salamander is closely related to the Chinese Giant Salamander. They can be distinguished from the Chinese Giant Salamander by forming tubercles on the head and throat. Their snout is also further rounded, and the tail is somewhat shorter.
How cute are they?
Although most of us consider them ugly animals with mottled and wrinkled dark skins, others consider them adorable because they are extremely camouflaged, found in only clear and calm water, blending with the environment.
How do they communicate?
Japanese Giant Salamanders, being nocturnal amphibians, use their senses of smell and touch to detect their surroundings, as their eyes are tiny and have little visual acuity. It is observed they have tactile communication between rival males and between a male and a female during the breeding season.
Chemical communication may play a role in this species. When irritated or stressed, they emit sticky, white mucus that may be poisonous to predators.
It smells like Japanese peppers and has a pungent odor. This has earned them the nickname 'big pepper fish' in Japan.
How big is a Japanese giant salamander?
According to records, the Japanese Giant Salamander is said to reach a length of 5 ft (1.5 m), but the world's largest wild specimen was 4.46 ft (1.37 m) long. It is the world's third-largest amphibian, ranking next to the South China giant salamander and the Chinese Giant Salamander.
How fast can a Japanese giant salamander move?
The exact speed of the Japanese Giant Salamanders has yet to be determined. Still, it is observed that they move very slowly because they are longer and heavier than other Salamanders.
In general, Salamanders move at speeds ranging from 0.22-1.78 mph (035-2.9 kph). Furthermore, due to their nocturnal nature, the Salamanders travel at an average speed of 1.02 mph (1.6 kph) at night and 0.51 mph (0.8 kph) during the day.
How much does a Japanese giant salamander weigh?
These animals are quite enormous; their body weight is around 55 lb (25 kg), while the heaviest wild species recorded was 58 lb (26 kg).
What are the male and female names of the species?
Since there are no official names for male and females Japanese Giant Salamanders, they are commonly referred to as male Japanese Giant Salamanders and female Japanese Giant Salamanders.
What would you call a baby Japanese giant salamander?
They begin their lives as eggs, then larvae, and finally, the young, a baby Japanese Giant Salamander, are known as a juvenile.
What do they eat?
Japanese Giant Salamanders are carnivores that consume fish, snails, insects, crayfish, and other small mammals. Do you know they have a slower metabolism so they can survive for weeks without eating food if required?
Since they have poor eyesight, they rely on smell and vibrations in the water to hunt. Moreover, bumps on their skin and around the head are external sensory organs that function similarly to a fish's sideline system.
These Japanese Giant Salamanders capture prey by sucking and creating negative pressure within the mouth with their tiny teeth-filled mouth. Prey usually cannot escape this Salamander's grip due to the significant jaw pressure exerted by its muscular head.
Are they poisonous?
Of course, every time we disturb nature, we endanger ourselves. When Japanese Giant Salamanders sense that they are about to be attacked, they eject a strong-smelling, milky substance with an odor similar to Japanese pepper, which can be dangerous to predators.
Would they make a good pet?
First of all, keeping these Japanese Giant Salamanders as pets is illegal. Furthermore, since this amphibian is very much sensitive to pollution, it is extremely difficult to provide them with a natural environment.
Did you know...
These Japanese Giant Salamanders also have great importance in ancient artwork. For instance, it has been the subject of legend Utagawa Kuniyoshi in his artwork known as ukiyo-e work, which is a collection of woodblock prints and paintings from the 17th century.
In addition, Kappa, the well-known Japanese mythological creature, was influenced by the Japanese Giant Salamanders.
Moreover, it is surprising to know that every year in Yubara, Maniwa city, in the region of Okayama, there's a Giant Salamander festival in honor of the animal and to celebrate its life. The Giant Salamander is named after Yubara as Hanzaki because they believe that they are still surviving even though they are torn in half (han).
How many eggs do Japanese giant salamanders lay?
Japanese Giant Salamander's reproduction is caused by spawning, in which the eggs and sperm are released into the water by these aquatic animals. A breeding Japanese Giant Salamander female animal lays 400-500 eggs in its spawning pit.
These eggs are bound together by a string-like material and look like threaded beads on a string. After reproduction, these eggs are further guarded by a male animal of the spawning pit known as a den master.
The Japanese Giant Salamander Bite
If you get a chance to meet this animal any time, do not attempt to mingle with it; the Japanese Giant Salamander can easily bite off a big chunk of your finger in a fraction of a second.
Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other amphibians from our olm surprising facts and bullfrog fun facts pages.
You can even occupy yourself at home by coloring in one of our free printable Japanese giant salamander coloring pages.