---
title: "What the sources say about the Japanese Giant Salamander | AnimalTracks.wiki"
description: "70 claims from the Japanese Giant Salamander profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/japanese-giant-salamander-1.webp"
canonical: "https://animaltracks.wiki/animals/japanese-giant-salamander/sources/"
---

# What the sources say about the Japanese Giant Salamander (*Andrias japonicus*)

> 70 claims from the Japanese Giant Salamander profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Japanese Giant Salamander](https://animaltracks.wiki/animals/japanese-giant-salamander/)

## Japanese giant salamander. Smithsonian's National Zoo and Conservation Biology Institute.

https://nationalzoo.si.edu/animals/japanese-giant-salamander

| The page says | The source says |
| :--- | :--- |
| Up to five feet of living river boulder | reaching lengths of up to 5 feet (1.5 meters) (note: tagline; 'living river boulder' is a metaphor) |
| breathes through its skin | Japanese giant salamanders "breathe" primarily through their skin (note: tagline) |
| hunts by smell and vibration | they rely on smell and vibrations in the water when hunting (note: tagline) |
| gives off a peppery smell when stressed | When aggravated or stressed, Japanese giant salamanders secrete a sticky, white mucus ... smells like Japanese peppers (note: tagline) |
| oxygen-rich | cold, fast-flowing water where oxygen is in good supply (note: habitat stat and body: 'the water carries plenty of oxygen') |
| Fish, crayfish, insects, snails | eat a variety of animals, including fish, insects, crayfish, snails and small mammals |
| and small mammals | eat a variety of animals, including fish, insects, crayfish, snails and small mammals (note: diet stat and body menu line) |
| Breathes mainly through its wrinkled skin | "breathe" primarily through their skin ... Flaps of skin, or wrinkles, increase the surface area for this respiration (note: superpower stat) |
| has sensory bumps around its head that work like a fish's lateral line | Bumps on their skin, located mostly around the head, are actually external sensory organs that operate similarly to the lateral line system in fish (note: superpower stat) |
| second-largest salamander species on Earth, after the Chinese giant salamanders | one of the largest salamander species in the world, second only to Chinese giant salamanders |
| It can reach 1.5 meters (5 feet) long and weigh up to 23 kilograms (55 pounds) | reaching lengths of up to 5 feet (1.5 meters) and weighing up to 55 pounds (23 kilograms) |
| Its wrinkled skin is mottled black and brown | wrinkled skin mottled with varying patterns of black and shades of brown |
| where the water carries plenty of oxygen | live in cold, fast-flowing water where oxygen is in good supply |
| It can live for more than 70 years | These salamanders can live for more than 70 years. |
| it breathes mainly through its skin | "breathe" primarily through their skin (note: the Smithsonian's current 'primarily' replaces ADW's older all-skin, no-lung-breathing account) |
| Its single lung is used mainly to control its buoyancy | single lung, but it is used primarily to control their buoyancy in the water (note: 'how high or low it floats' defines buoyancy) |
| Its eyesight is poor, so it hunts by smell and by sensing vibrations in the water | They have poor eyesight, so they rely on smell and vibrations in the water when hunting. |
| Bumps on its skin, mostly around the head, are sense organs that work like a fish's lateral line | Bumps on their skin, located mostly around the head, are actually external sensory organs that operate similarly to the lateral line system in fish (note: the clause after it defines 'lateral line' for young readers) |
| When aggravated or stressed, a Japanese giant salamander oozes a sticky white mucus that may be toxic to predators | When aggravated or stressed, Japanese giant salamanders secrete a sticky, white mucus that may be toxic to predators. |
| It smells like Japanese pepper | The sticky secretion has a pungent odor and smells like Japanese peppers. |
| which gave the species a Japanese name that translates to "big pepper fish" | This has given them a common name in Japan that translates to "big pepper fish." (note: blockquote lead-in 'The Big Pepper Fish' is the same name) |
| From August to October, the salamanders migrate upriver to spawn in dens: caverns, or burrows | These salamanders spawn from August through October. During this season, they migrate upriver looking for "dens" — caverns or burrows |
| burrows 1 to 1.5 meters long in or near the riverbank | 100 to 150 centimeter) long burrows into or near the riverbank |
| The largest, most dominant male on a stretch of river takes over a den | The largest, most dominant male in a territory of river will occupy the den and defend it. |
| Several females may spawn in one den, each typically laying 400 to 600 eggs | multiple females may enter the den and spawn with the male. Females typically lay a clutch of 400-600 eggs. (note: the Smithsonian's current 400-600 is used over ADW's 400-500) |
| The male, sometimes called the den master, fertilizes them, and once the females leave, protecting the eggs is his job | Once the females have laid their eggs and the male has fertilized them, the females leave the den. It is now the male’s job to provide protection ... The male, sometimes referred to as the "den master," |
| Incubation takes 40 to 60 days | This incubation period ranges from 40-60 days. (note: the Smithsonian's current figure; ADW's older account gives 12 to 15 weeks) |
| second-largest salamander species in the world, after the Chinese giant salamanders | one of the largest salamander species in the world, second only to Chinese giant salamanders (note: faq 1) |
| It can reach 1.5 meters (5 feet) long and weigh up to 23 kilograms (55 pounds), and it can live for more than 70 years | reaching lengths of up to 5 feet (1.5 meters) and weighing up to 55 pounds (23 kilograms) ... These salamanders can live for more than 70 years. (note: faq 1) |
| When aggravated or stressed, it oozes a sticky white mucus that may be toxic to predators | When aggravated or stressed, Japanese giant salamanders secrete a sticky, white mucus that may be toxic to predators. (note: faq 2) |
| The secretion has a pungent smell like Japanese peppers, which gave the species a Japanese common name that translates to "big pepper fish." | The sticky secretion has a pungent odor and smells like Japanese peppers. This has given them a common name in Japan that translates to "big pepper fish." (note: faq 2) |

## Andrias japonicus. Animal Diversity Web, University of Michigan.

https://animaldiversity.org/accounts/Andrias_japonicus/

| The page says | The source says |
| :--- | :--- |
| Cold, fast-flowing, oxygen-rich mountain streams | cold, swift, mountain streams (note: habitat stat; "fast-flowing" for "swift", which battleEngine.ts reads as a speed keyword) |
| western Honshu and northern Kyushu, Japan | native to the northern region of Kyushu Island and western Honshu island of Japan (note: habitat stat) |
| worms | Giant Japanese salamanders also eat worms (note: diet item ADW gives that the Smithsonian list doesn't) |
| Its head is flat and wide | sit on the top of the wide, flat head |
| its eyes are small and lidless | Small, lidless eyes sit on the top of the wide, flat head. |
| It lives in cold, fast-flowing mountain streams | These salamanders reside in and around the cold, swift, mountain streams of the Japanese islands. (note: "fast-flowing" for "swift", which battleEngine.ts reads as a speed keyword) |
| in western Honshu and northern Kyushu, in Japan | native to the northern region of Kyushu Island and western Honshu island of Japan |
| from 180 to 1,350 meters above sea level | found at elevations between 180 and 1,350 meters |
| This salamander has no gill openings | these particular salamanders lack gill openings |
| Wrinkles and folds add surface area for swapping oxygen and carbon dioxide with the water | The wrinkles of the warty epidermis provide increased surface area, facilitating the exchange of carbon dioxide and oxygen with the water. |
| tiny blood vessels called capillaries run close to the surface, so gases pass through easily | Capillaries run close to the surfaces of the skin, allowing for the easy diffusion of gases. |
| males fiercely defend the same one for many years | Males ferociously defend and occupy a particular spawning pit for many years. |
| Larger males have killed and eaten smaller ones in the breeding season | Smaller males have been killed and eaten by larger males during the reproductive season. |
| strung together like beads | held together with a string-like substance and resemble threaded beads on a string |

## オオサンショウウオを伊丹市内で見つけたら (If you find a Japanese giant salamander in Itami). Itami City, Cultural Promotion Division.

https://www.city.itami.lg.jp/SOSIKI/TOSHIKATSURYOKU/BUNKA/bunnkazai/BUNKAZAI/1386838361652.html

| The page says | The source says |
| :--- | :--- |
| dangerLevel: Medium | オオサンショウウオは 目の前に動くものがあると反射的に噛みつきます (note: Itami City: it bites by reflex at anything moving in front of it, and a careless touch risks a bite. A bite to a person is 'can injure'; no source found states how serious bites are, and the page's 大変危険です ('very dangerous') is a warning against illegal capture, not an injury report, so it does not lift the tier to High) |
| dangerLevel: Medium | 不用意に触ると噛みつかれる危険性もあり |

## Andrias japonicus. The IUCN Red List of Threatened Species 2022: e.T1273A177177761.

https://doi.org/10.2305/iucn.uk.2022-2.rlts.t1273a177177761.en

| The page says | The source says |
| :--- | :--- |
| Vulnerable | IUCN Red List category: Vulnerable (VU). |

## Terry et al. (2018). Preoviposition paternal care in a fully aquatic giant salamander: nest cleaning by a den master. Journal of Zoology.

https://doi.org/10.1111/jzo.12615

| The page says | The source says |
| :--- | :--- |
| Before spawning, one den master filmed at a zoo in Hiroshima paddled the nest floor with his front and hind legs every day | we videotaped and examined a single den master's pre‐ and postoviposition behaviours at Asa Zoological Park in Hiroshima, Japan. The den master repeatedly exhibited vigorous movements of front and hind limbs in a paddling motion at the bottom of the nest every day |
| That stirred up leaves and twigs buried in the sand, and the current carried them away | the den master made the den filled with debris including leaves and twigs buried in the sand. The floating debris was subsequently removed by the water current flowing through the nest. |
| Clearing that debris likely leaves less food for water mold, a major cause of death among the young | Water mould infection is a major cause of offspring mortality of aquatic amphibians including A. japonicus . By reducing the amount of organic matter that provides food sources for water mould, the nest cleaning likely reduces the risk |

## Okada, Fukuda & Takahashi (2014). Paternal care behaviors of Japanese giant salamander Andrias japonicus in natural populations. Journal of Ethology.

https://doi.org/10.1007/s10164-014-0413-5

| The page says | The source says |
| :--- | :--- |
| Two den masters filmed with their eggs in natural streams | We videotaped post-breeding behaviors of two den-masters that stayed with the eggs, one in a natural and the other in an artificial nest in natural streams. |
| fanned them with their tails to bring in oxygenated water | Tail fanning provides oxygenated water for the eggs. |
| stirred them with their heads and bodies, which likely stops the yolk sticking | Agitating the eggs with its head and body likely prevents yolk adhesions. |
| They also ate whiter eggs that looked dead or moldy, which likely keeps the mold from spreading to healthy eggs | The den-masters selectively ate whiter eggs that appeared to be dead or infected with water mold. This behavior, which we termed hygienic filial cannibalism, likely prevents water mold from spreading over healthy eggs. |
| A den master is a large male that occupies a burrow along a stream bank for breeding and nesting | large males, called den-masters, occupy burrows along stream banks for breeding and nesting (note: faq 3) |
| Researchers who filmed two den masters with their eggs in natural streams | We videotaped post-breeding behaviors of two den-masters that stayed with the eggs, one in a natural and the other in an artificial nest in natural streams. (note: faq 3) |
| fan the eggs with their tails to bring in oxygenated water | Tail fanning provides oxygenated water for the eggs. (note: faq 3) |
| stir them with their heads and bodies, which likely stops the yolk sticking | Agitating the eggs with its head and body likely prevents yolk adhesions. (note: faq 3) |
| They also ate whiter eggs that looked dead or infected with water mold, which likely stops the mold spreading to healthy eggs | The den-masters selectively ate whiter eggs that appeared to be dead or infected with water mold. This behavior, which we termed hygienic filial cannibalism, likely prevents water mold from spreading over healthy eggs. (note: faq 3) |
| The researchers called this hygienic filial cannibalism | This behavior, which we termed hygienic filial cannibalism (note: faq 3; the clause after it defines the term) |

## Takahashi, Okada & Fukuda (2016). From embryos to larvae: seven‐month‐long paternal care by male Japanese giant salamander. Journal of Zoology.

https://doi.org/10.1111/jzo.12433

| The page says | The source says |
| :--- | :--- |
| one male stayed with his hatched larvae until they dispersed the following spring | While one male abandoned the nest, the other male remained in the nest and provided care until the larvae dispersed in the following spring. |
| seven months of care, from eggs to larvae | From embryos to larvae: seven‐month‐long paternal care by male Japanese giant salamander (note: the figure is the reference's own title, which audit:sources matches against the DOI's Crossref record; the cached abstract does not repeat it) |

## Kawano et al. (2024). Applying 3D Models of Giant Salamanders to Explore Form–Function Relationships in Early Digit-Bearing Tetrapods. Integrative And Comparative Biology.

https://doi.org/10.1093/icb/icae129

| The page says | The source says |
| :--- | :--- |
| weightKg: 7.8 | 87 cm total length and 7.8 kg total weight (note: a measured large male ('Hiro'); settled in #533, which moved the value from ADW's 25 kg maximum) |

## Matsumoto, Fujiwara & Evans (2024). The anatomy and feeding mechanism of the Japanese giant salamander (Andrias japonicus). Journal of Anatomy.

https://doi.org/10.1111/joa.14004

| The page says | The source says |
| :--- | :--- |
| It feeds by suction | Their feeding behaviour is characterized by a form of suction feeding |
| The side of its jaw closest to the prey drops open | asymmetric jaw movements are linked to the position of the prey in relation to the snout, with the jaw closest to the prey opening asymmetrically |
| the salamander can hold its catch in one side of its mouth while pushing water out the other if its first suction attempt fails | allows the salamander to simultaneously grasp prey in one side of the mouth while ejecting water on the other side, if the first suction attempt fails |
| By suction | Their feeding behaviour is characterized by a form of suction feeding (note: faq 4) |
| Researchers filming it feed found that the side of its jaw closest to the prey drops open | Our filming revealed that asymmetric jaw movements are linked to the position of the prey in relation to the snout, with the jaw closest to the prey opening asymmetrically. (note: faq 4) |
| hold prey in one side of its mouth while pushing water out the other side if its first suction attempt fails | allows the salamander to simultaneously grasp prey in one side of the mouth while ejecting water on the other side, if the first suction attempt fails (note: faq 4) |