We report on verified cases of longevity in the Japanese Fire-bellied Newt Cynops pyrrhogaster. Two individuals obtained as adults in 1978 died in July 2008 and November 2017, resulting in an individual minimum lifespan of 33 and 42 years, respectively, possibly even longer. Another four individuals of C. pyrrhogaster were received in 1975 and living now for more than 47 years, with two individuals received as adults likely having reached a lifespan of 50 years already. Another adult male C. pyrrhogaster was obtained in 1991 and died in 2022 at an accordingly estimated age of >34 years. Previously reported lifespans for C. pyrrhogaster in human care were 20-25 years, with only a single report of 40 years. However, other species of Cynops and Hypselotriton are also apparently long-lived, such as H. cyanurus chuxiongensis (25 years), H. orientalis (32 years), and C. ensicauda (43 years). With these documented cases, the lifespan of Fire-bellied Newts is exceeded only by few other species of Caudata, such as Andrias japonicus (70 years), Cryptobranchus alleganiensis, Salamandra salamandra (>50 years), and Proteus anguis (100 years). Our report thus indicates that decades-long lifespans in salamandrid newts, viz. substantial longevity, might be rather common and could be considered a rule, not an exception.
INTRODUCTION
Asian Fire-bellied Newts of the genus Cynops Tschudi, 1838 were imported to Europe and North America at least since the 1950s (Axelrod, 1958) for the pet trade and anecdotal reports mention them as having been present in almost every small pet shop at certain periods. Among the ten species currently recognized (Frost, 2022), the Japanese Cynops pyrrhogaster (Boie, 1826) apparently was most prevalent in the commercial trade of these newts when it started. As a result, thousands of these newts were kept in small aquaria by teenagers and adults in Europe and North America – and many of them for long time. Various internet reports by keepers indicate that Cynops species may reach a remarkable individual age. However, most reports are anecdotal in character only and hard to prove. In the following, we report three verified cases of longevity of C. pyrrhogaster.
MATERIALS AND METHODS
The age records reported herein are both based on our own findings and that of colleagues. Identification was based on photographs and morphological diagnostic characters (details given in the results). Measurements were taken with a digital calliper in preserved specimens and a measuring rule in living individuals and rounded to the nearest 1.0 mm. Deceased individuals were deposited in the following zoological collections: Hessisches Landesmuseum Darmstadt (HLMD) and the Museum of Comparative Zoology, Harvard (MCZ).
RESULTS
The first case: In the year 1978, as a teenager at the age of 15, palaeontologist Gottfried Klappert, purchased two adult Fire-bellied Newts in a small pet shop at Kelkheim (Taunus), a small city west of Frankfurt, Germany. These two individuals were kept in a small paludarium and mainly fed with earthworms (Lumbricidae) at his home with one dying in July 2008 and the other on 2 November 2017. Both individuals were preserved and donated to the zoological collection of the Hessisches Landesmuseum Darmstadt.
Both specimens are adult females in a rather poor state of preservation (Fig. 1A), as they were not found promptly following their deaths in the paludarium. The smaller individual which died in 2008 (HLMD-RA-3213) has a snout-vent length of 48 mm and a total length of 89 mm, the larger and older individual (HLMD-RA-3212) has 55 mm snout-vent length and 101 mm total length. Despite the poor state of preservation, both specimens were identified as C. pyrrhogaster based on the following morphological characters: rugose dorsal skin, elevated vertebral ridge, and prominent, elongated parotoid glands, which distinguish them from H.. orientalis.
Fig. 1.
Individuals of long-lived Cynops pyrrhogaster. (A) Preserved female specimens HLMD-RA-3212 and HLMD-RA-3213 in ventral views, having reached a lifespan of at least 42 and 33 years, respectively. (B) Two individuals (still alive) kept by H. Janssen which reached a lifespan of at least 47 years already. (C) Male MCZ:Herp:A-153484 in life, having reached a lifespan of at least 34 years.
Considering that both individuals were fully adult when bought in the pet shop in 1978 and maturity in C. pyrrhogaster normally is reached after 3 years from hatching (Franzen & Franzen, 2005; Sparreboom, 2014), the individual lifespan of the two specimens considered is at least 33 and 42 years, respectively, possibly even longer.
The second case: Four individuals of C. pyrrhogaster, two adult females of unknown age and two male juveniles, were received in 1975 by one of the authors (H. Janssen) and have been kept alive to the present day. These individuals have thus lived more than 47 years, with the two individuals received as adults likely having already reached a lifespan of 50 years. While the females stopped laying eggs many years ago, the males are still showing reproductive behaviour (Fig. 1B). Current total length of the two males is 108 and 111 mm, respectively, that of the two females is 139 and 169 mm, respectively1. The third case: One author (M. Gage) received an apparently wild-caught adult male C. pyrrhogaster from a Massachusetts (U.S.A.) pet store in 1991 that died in human care on 6 February 2022 (specimen donated to the Museum of Comparative Zoology, Harvard; MCZ:Herp:A-153484; Fig. 1C), at an accordingly estimated age of >34 years with 59 mm snout-vent length and 101 mm total length.
DISCUSSION
While age records of 20-25 years are not exceptional for Cynops pyrrhogaster (Sparreboom, 2014) and even historical literature reports refer to 25 years under human care for the species (Wolterstorff, 1928; Senning, 1940), there are only few documented cases of Fire-bellied Newts exceeding an individual age of 40 years (Bogaerts, 2013). Skeletochronological studies estimated the maximum age of wild-caught female C. pyrrhogaster to be 16 years (Marunochi et al., 2000).
With our documented cases of more than 47 years of age, the lifespan of C. pyrrhogaster is exceeded only by few other species of Caudata (see summary by Warburg, 2007). Among them: Andrias japonicus (Temminck, 1836) reaching 70 years (Schneider, 1932), or more than 60 years in human care (Nickerson, 2003), Cryptobranchus alleganiensis (Sonnini de Manoncourt & Latreille, 1801) reaching 55 years in human care (Nigrelli, 1954), and the record holder Proteus anguis with 100 years in human care (Aljancic, 1993). The freeze-tolerant Salamandrella keyserlingii Dybowski, 1870 represents a special case of longevity, with a thawed individual reported to have emerged alive from permafrost soil after 90 ± 15 years (Aubert, 2002).
Within the family Salamandridae, the maximum documented lifespan of C. pyrrhogaster is only equalled by Salamandra salamandra (Linnaeus, 1758), kept for more than 50 years (Böhme, 1979). However, other species of Cynops and Hypselotriton (formerly also in Cynops; see Dubois & Raffaёlli, 2009) are also apparently long-lived. Hypselotriton cyanurus chuxiongensis (Fei & Ye, 1983) lived in human care for 25 years (Ke Jiang, Chengdu Institute of Biology, pers. comm.), H. orientalis (David, 1873) (1 male, 8 females) has been kept alive for 32 years by one author (H. Janssen), and C. ensicauda (Hallowell, 1861) for 43 years by another keeper (Sergé Bogaerts, The Netherlands, pers. comm.). Longevity has further been documented in the genus Tylototriton, with T. ziegleri Nishikawa, Matsui & Nguyen, 2013 having reached an estimated age of at least 23-28 years (Ziegler et al., 2018).
Our report indicates that decades-long lifespans in salamandrid newts, viz. substantial longevity, might be rather common and could be considered a rule, not an exception.
ACKNOWLEDGEMENTS
We are very grateful to Gottfried Klappert and Mechthild Haas for donating the two specimens to the HLMD collection and providing respective information, as well as to Sergé Bogaerts for sharing information about individuals kept. Yunke Wu and Ke Jiang provided the age record of Hypselotriton cyanurus chuxiongensis formerly held by Guangfu Wu. Rene Rijnbrand and Jennifer Macke provided additional background information.
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