Honolulu Zoo’s Japanese Giant Salamanders Could be Parents-to-be

It's the first time the amphibians have laid and fertilized eggs outside of Japan.

November 9, 2018

Honolulu Family Team,

Courtesy: City & County of Honolulu

The Japanese giant salamanders and I have some history. Just a few months after they arrived at the Honolulu Zoo from Hiroshima, Japan, HONOLULU Magazine’s Robbie Dingeman and I were on a behind-the-scenes tour and got to peek at the trio that were in quarantine.

Three years later, as a parent would say, they’re all grown up. Well, more grown up. In September, 13-year-old Panda laid eggs in her habitat. Then, her partner, 11-year-old Peace, appeared to have fertilized them. It is the first Japanese giant salamanders in captivity to produce eggs in a zoo outside of Hiroshima City Asa Zoological Park. Hiroshima is Honolulu’s sister city and Honolulu’s zoo is one of only four others in the U.S. to have the second largest salamanders in the world.

There is no guarantee that the eggs will hatch after the gestation period, which is 40 to 90 days. But zookeepers on either side of the ocean are still pleased with the development.

Courtesy: Hiroshima City Asa Zoological Park.

An example of Japanese giant salamander eggs, also called Hanzaki eggs.

“Even if these eggs are not successful we are proud of our staff’s accomplishments in getting the animals to feel comfortable in their habitat to breed, and at a very early age for these animals,” said Honolulu Zoo Director Linda Santos in a press release.

If the eggs continue to develop, they may hatch in early December.

Fast facts about Japanese giant salamanders:

The amphibians are endemic to Japan and are considered near threatened.
There are three types of giant salamanders in the world. The largest is the Chinese salamander which can grow up to six feet long. The smallest is the North American hellbender.
Salamanders live in rocky, fast-flowing streams where the swiftly moving water helps provide them a good supply of oxygen.
Each has a single lung used for buoyancy, not to breathe. They usually stay submerged but can spend some time on the surface, as long as their skin is moist.
Salamanders’ respiratory system is in their skin. Oxygen enters the body and is carbon dioxide is released through the skin, including flaps which increase the area for this to happen.
How fast eggs develop depends on the temperature of the water. The water in the Honolulu Zoo’s salamander den is fairly cool, 62 degrees Farenheit so eggs would hatch on the earlier side of the gestation period.
Japanese giant salamanders have bad eyesight. They use touch and smell to capture prey including fish, smaller salamanders, insects, crayfish and snails as well as turtles, snakes and small mammals.
They are considered adults, or mature, at five years and can live for decades. At the Amsterdam Zoo, a Japanese giant salamander lived until the age of 52.