Total length of males to 133 mm for males (average 122 mm), up to 150 mm for females (average 111 mm. Adult males have a mental gland on the chin. Limbs well developed, hind legs slightly longer than front legs. Front feet with 4, hind feet with 5 broad, flattened digits that are widened distally. Base color from dark brown to black, with marbled pattern. Pattern may be in yellow, ochre or green. The base color is either bright ("imperialis"-type) or dark ("funereus"-type). The dark V, inverted V or X pattern in the neck, as also described for H. flavus, can also be present in this species. The ventral side is bright and sometimes translucent, showing the abdominal organs and their contents. The brown or black spotting of the throat, venter and tail is stronger in this species than in H. flavus. There are no cases of albinism known for this species (Boehme et al 1999).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Italy
H. imperialis is an endemic of Central, Central-eastern and Southeastern Sardinia, occurring roughly between 40º N and 39º30' N, westwards as far as 08º55' E, in the provences of Nuoro, Oristano and Cagliari (Gasc 1997).The preferred temperature of H. imperialis and other Sardinian Hydromantes species is slightly higher than that of mainland species. H. imperialis is very abundant, like other Hydromantes species, in caves and under rocks (Boehme et al 1999).
Life History, Abundance, Activity, and Special Behaviors
Ecology and habitat of H. imperialis is similar to that of H. ambrosii. H. imperialis has been bred in captivity. Observations on the reproductive biology of this species were made in aterrarium that was kept at 8-12º C in wintertime and up to 15º C in summertime. Unfortunately, there were no observations on the mating or the spermatophores. On January 17th,, 1996, a clutch of freshly laid eggs were found with diameters of 5-6mm. The female kept close to the eggs and only left her eggs for short foraging escapades at night. Two eggs were eaten. The first three eggs hatched after 173 days (on July 5th), followed by the fourth, a good two days later. The hatchlings had an average total length of 26.7mm The juveniles remained in the vicinity of the female for 14 days, living on the remaining yolk, before they spread out and started to feed.
This species can be very abundant locally, depending on the season. The concentration of H. imperialis reaches the highest concentrations of any European Plethodontid in some caves. In one instance the Grotta degli Spelerpes contained at least 500 individuals in the first 10-12 meters (Boehme et al 1999).
This species is unique in producing a strong smell when handled, hence the Italian common name "Geotritone oderoso".
Trends and Threats
This species is not endangered. It is abundant in a relatively large and mostly inaccessible area (Boehme et al 1999).
Boehme, W., Grossenbacher, K., and Thiesmeier, B. (1999). Handbuch der Reptilien und Amphibien Europas, band 4/I:Schwanzlurche (Urodela). Aula-Verlag, Wiesbaden.
Gasc, J.-P. (1997). Atlas of Amphibians and Reptiles in Europe. Societas Europaea Herpetologica, Bonn, Germany.
Stumpel-Rieks, S. E. (1992). Nomina Herpetofaunae Europaeae. AULA-Verlag, Wiesbaden.
Written by Arie van der Meijden (amphibia AT arievandermeijden.nl), Research associate, Museum of Vertebrate Zoology, UC Berkeley
First submitted 1999-11-30
Edited by David B. Wake (Jan. 2000) (2002-05-25)
Species Account Citation: AmphibiaWeb 2002 Hydromantes imperialis: Imperial Cave Salamander <http://amphibiaweb.org/species/4075> University of California, Berkeley, CA, USA. Accessed May 24, 2020.
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Citation: AmphibiaWeb. 2020. <http://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 May 2020.
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