Reproduction technologies for the sustainable management of Caudata (salamander) and Gymnophiona (caecilian) biodiversity
Robert K. Browne![https://orcid.org/0000-0002-3172-9991](/media/client/orcid_16x16.png)
![https://orcid.org/0000-0002-2298-1597](/media/client/orcid_16x16.png)
![https://orcid.org/0000-0003-2316-3382](/media/client/orcid_16x16.png)
![https://orcid.org/0000-0002-7758-7677](/media/client/orcid_16x16.png)
![https://orcid.org/0000-0003-4873-7418](/media/client/orcid_16x16.png)
![https://orcid.org/0000-0002-4357-7577](/media/client/orcid_16x16.png)
A Sustainability America, La Isla Road, Sarteneja, Corozal District, Belize.
B Institute of Cell Biophysics of the Russian Academy of Sciences, PSCBR RAS, Pushchino, Moscow Region 142290, Russia.
C Laboratory for the Conservation of Endangered Species, CSIR-Centre for Cellular and Molecular Biology, Hyderabad, Telangana 500048, India.
D Ectotherm Department, Nashville Zoo at Grassmere, Nashville, TN 37211, USA.
E Department of Zoology, Centre for Applied Genetics, Bangalore University, Jnana Bharathi Campus, Bengaluru, Karnataka 560056, India.
F Departamento de Produccion Animal, Universidad de Guadalajara, Guadalajara, Jalisco, Mexico.
G National Amphibian Conservation Center Detroit Zoological Society, Detroit, MI, USA. Honduras Amphibian Rescue and Conservation Center, Oak Grove Missouri 64075
Reproduction, Fertility and Development 34(6) 479-497 https://doi.org/10.1071/RD21356
Published online: 15 February 2022
© 2022 The Author(s) (or their employer(s)). Published by CSIRO Publishing
Abstract
We review the use of reproduction technologies (RTs) to support the sustainable management of threatened Caudata (salamanders) and Gymnophiona (caecilian) biodiversity in conservation breeding programs (CBPs) or through biobanking alone. The Caudata include ∼760 species with ∼55% threatened, the Gymnophiona include ∼215 species with an undetermined but substantial number threatened, with 80% of Caudata and 65% of Gymnophiona habitat unprotected. Reproduction technologies include: (1) the exogenous hormonal induction of spermatozoa, eggs, or mating, (2) in vitro fertilisation, (3) intracytoplasmic sperm injection (ICSI), (4) the refrigerated storage of spermatozoa, (5) the cryopreservation of sperm, cell or tissues, (6) cloning, and (7) gonadal tissue or cell transplantation into living amphibians to eventually produce gametes and then individuals. Exogenous hormone regimens have been applied to 11 Caudata species to stimulate mating and to 14 species to enable the collection of spermatozoa or eggs. In vitro fertilisation has been successful in eight species, spermatozoa have been cryopreserved in seven species, and in two species in vitro fertilisation with cryopreserved spermatozoa has resulted in mature reproductive adults. However, the application of RTs to Caudata needs research and development over a broader range of species. Reproduction technologies are only now being developed for Gymnophiona, with many discoveries and pioneering achievement to be made. Species with the potential for repopulation are the focus of the few currently available amphibian CBPs. As Caudata and Gymnophiona eggs or larvae cannot be cryopreserved, and the capacity of CBPs is limited, the perpetuation of the biodiversity of an increasing number of species depends on the development of RTs to recover female individuals from cryopreserved and biobanked cells or tissues.
Keywords: ART, assisted reproduction technologies, biobanking, caecilian, Caudata, CBPs, conservation breeding programs, cryopreservation, Gymnophiona, hormones, in vitro fertilisation, repopulation, reproduction technologies, salamander, sperm cryopreservation.
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