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An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan.

Igawa T, Sugawara H, Tado M, Nishitani T, Kurabayashi A, Islam MM, Oumi S, Katsuren S, Fujii T, Sumida M - Animals (Basel) (2013)

Bottom Line: Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront.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.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.

View Article: PubMed Central - PubMed

Affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. tigawa@hiroshima-u.ac.jp.

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.

No MeSH data available.


Normal development from the neurula to hatching stages: (a) 8-day-old neurula embryo, (b) 9-day-old tailbud embryo, (c) 10-day-old larva, (d) 11-day-old larva, (e) 12-day-old larva, (f) 13-day-old larva, (g) 14-day-old larva, (h) 15-day-old larva, (i) 16-day-old larva, (j) 17-day-old larva, (k) 18-day-old larva, (l) 19-day-old larva, (m) 20-day-old hatched larva.
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animals-03-00680-f006: Normal development from the neurula to hatching stages: (a) 8-day-old neurula embryo, (b) 9-day-old tailbud embryo, (c) 10-day-old larva, (d) 11-day-old larva, (e) 12-day-old larva, (f) 13-day-old larva, (g) 14-day-old larva, (h) 15-day-old larva, (i) 16-day-old larva, (j) 17-day-old larva, (k) 18-day-old larva, (l) 19-day-old larva, (m) 20-day-old hatched larva.

Mentions: Eggs were deposited on the slope in the vicinity of each cage’s waterfront during the breeding seasons over the 5 years of the breeding program (Figure 4). Normal development was shown from the neurula to hatching stages (Figure 6). Eggs of this species were greyish and comparatively large, with a diameter of 3.0 ± 0.1 mm. Most embryos reached the neurula stage eight days after oviposition (Figure 6(a)), the tailbud stage nine days after oviposition (Figure 6(b)), and hatched into larvae at 20 days after oviposition (Figure 6(m)). Finally, they completed metamorphosis within 3–4 months of oviposition. The present data were compared with those of Utsunomiya and Utsunomiya [23] and no differences were found.


An Attempt at Captive Breeding of the Endangered Newt Echinotriton andersoni, from the Central Ryukyus in Japan.

Igawa T, Sugawara H, Tado M, Nishitani T, Kurabayashi A, Islam MM, Oumi S, Katsuren S, Fujii T, Sumida M - Animals (Basel) (2013)

Normal development from the neurula to hatching stages: (a) 8-day-old neurula embryo, (b) 9-day-old tailbud embryo, (c) 10-day-old larva, (d) 11-day-old larva, (e) 12-day-old larva, (f) 13-day-old larva, (g) 14-day-old larva, (h) 15-day-old larva, (i) 16-day-old larva, (j) 17-day-old larva, (k) 18-day-old larva, (l) 19-day-old larva, (m) 20-day-old hatched larva.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494449&req=5

animals-03-00680-f006: Normal development from the neurula to hatching stages: (a) 8-day-old neurula embryo, (b) 9-day-old tailbud embryo, (c) 10-day-old larva, (d) 11-day-old larva, (e) 12-day-old larva, (f) 13-day-old larva, (g) 14-day-old larva, (h) 15-day-old larva, (i) 16-day-old larva, (j) 17-day-old larva, (k) 18-day-old larva, (l) 19-day-old larva, (m) 20-day-old hatched larva.
Mentions: Eggs were deposited on the slope in the vicinity of each cage’s waterfront during the breeding seasons over the 5 years of the breeding program (Figure 4). Normal development was shown from the neurula to hatching stages (Figure 6). Eggs of this species were greyish and comparatively large, with a diameter of 3.0 ± 0.1 mm. Most embryos reached the neurula stage eight days after oviposition (Figure 6(a)), the tailbud stage nine days after oviposition (Figure 6(b)), and hatched into larvae at 20 days after oviposition (Figure 6(m)). Finally, they completed metamorphosis within 3–4 months of oviposition. The present data were compared with those of Utsunomiya and Utsunomiya [23] and no differences were found.

Bottom Line: Over the last five breeding seasons, eggs were laid in-cage on slopes near the waterfront.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.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.

View Article: PubMed Central - PubMed

Affiliation: Institute for Amphibian Biology, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashihiroshima 739-8526, Japan. tigawa@hiroshima-u.ac.jp.

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.

No MeSH data available.