title: An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan.
abstract: Anderson's crocodile newt (Echinotriton andersoni) is distributed in the Central Ryukyu Islands of southern Japan, but environmental degradation and illegal collection over the last several decades have devastated the local populations. It has therefore been listed as a class B1 endangered species in the IUCN Red List, indicating that it is at high risk of extinction in the wild. The species is also protected by law in both Okinawa and Kagoshima prefectures. An artificial insemination technique using hormonal injections could not be applied to the breeding of this species in the laboratory. In this study we naturally bred the species, and tested a laboratory farming technique using several male and female E. andersoni pairs collected from Okinawa, Amami, and Tokunoshima Islands and subsequently maintained in near-biotopic breeding cages. Among 378 eggs derived from 17 females, 319 (84.4%) became normal tailbud embryos, 274 (72.5%) hatched normally, 213 (56.3%) metamorphosed normally, and 141 (37.3%) became normal two-month-old newts; in addition, 77 one- to three-year-old Tokunoshima newts and 32 Amami larvae are currently still growing normally. Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront. Larvae were raised in nets maintained in a temperature-controlled water bath at 20 °C and fed live Tubifex. Metamorphosed newts were transferred to plastic containers containing wet sponges kept in a temperature-controlled incubator at 22.5 °C and fed a cricket diet to promote healthy growth. This is the first published report of successfully propagating an endangered species by using breeding cages in a laboratory setting for captive breeding. Our findings on the natural breeding and raising of larvae and adults are useful in breeding this endangered species and can be applied to the preservation of other similarly wild and endangered species such as E. chinhaiensis.
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. tigawa@hiroshima-u.ac.jp.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Igawa
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. sugawara-hirotaka@ed.tmu.ac.jp.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Sugawara
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. m131250@hiroshima-u.ac.jp.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Tado
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. nitroof1@hotmail.com.
authors.forename: Takuma
authors.initials: T
authors.lastname: Nishitani
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. kuraba@hiroshima-u.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kurabayashi
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. mafizul77@yahoo.com.
authors.forename: Mohammed Mafizul
authors.initials: MM
authors.lastname: Islam
authors.affiliation: Section of Agriculture and Forestry, Amami City Government, Amami, Kagoshima 894-0048, Japan. shoooumi@city.amami.lg.jp.
authors.forename: Shohei
authors.initials: S
authors.lastname: Oumi
authors.affiliation: Okinawa Prefectural Institute of Health and Environment, Okinawa 901-1202, Japan. skatsuren@gmail.com.
authors.forename: Seiki
authors.initials: S
authors.lastname: Katsuren
authors.affiliation: Faculty of Human Culture & Science, Hiroshima Prefectural University, Hiroshima 734-8558, Japan. fujii@pu-hiroshima.ac.jp.
authors.forename: Tamotsu
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. msumida@hiroshima-u.ac.jp.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sumida
keywords: Echinotriton andersoni; IUCN Red List; captive breeding; endangered newt; natural monument