Description
Large newt with a broad, dorsoventally flattened head. The back is covered with small warts and is usually gray to brown in color, sometimes with irregular dark spots. Rarely, the back is yellowish, greenish or black. There are conspicuous dorso-lateral rows of 7-10 yellow-orange warts, through which the ribs can protrude (Boehme et al 1999). Total length of males to 312mm, up to 286mm for females. Specimens from northern Africa are smaller than those from European populations. Tail length is smaller than snout-vent length. The tails of females are shorter than those of males. Males also show a broader tail-base and fin during the breeding season. During this period, males also develop nuptial pads on the front legs, and a reddish hue on the body (Griffiths 1996).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Morocco, Portugal, Spain

	View distribution map in BerkeleyMapper.
	View Bd and Bsal data (17 records).

The species is found only in Spain, Portugal and Morocco. However, there is another species in Africa, P. poiretti, which has been considered sometimes to be a subspecies of the Spanish newt. In Portugal, it is found throughout the country, but only in warm, non-mountainous areas, being more abundant towards the south. In Spain it lives mainly in the southern half of the country. It was formerly thought to be absent on the Mediterranean coast, however new localities have been discovered for that area. The distribution range crosses the Ebro River on the coast of Cataluña and the Duero River in several places, reaching the vicinity of Burgos. The northern extreme of the range is not far from the town of Leon. For the other geographic extremes, to the east, the Cataluña coast, between the mouth of the Ebro River and the town of Tarragona. In the European range, the southern most populations are in Tarifa, near the Gibraltar straits. In Africa, the animal reaches Mogador. To the west, the Portuguese coast, between Roca Cape and Cavoeiro Cape. In Morocco, the species is found in the humid, semi-humid and semi-arid zones of the northwestern part of the country. The Moroccan range roughly forms a triangle between the three localities Talmagaït, Safi and Ile d'Essaouira (Bons and Beniez 1996). It seems that the Iberian block was the area of origin for the genus Pleurodeles, whose fossils appear in the upper Miocene layers, and it might have crossed to Africa during the Messinian dry period. Differentiation of African forms may have started at the beginning of the Pliocene, when the Strait of Gibraltar was opened, or floded by ocean. P. waltl lives in small permanent or temporary ponds with quiet water. Although the ponds may be small, they must preferably be deep, commonly at least one meter deep when full. The species can tolerate some organic pollution and some salinity, being able to live with or without aquatic vegetation. It is rarely found on land, and then remains near the water. However, as the occupied pond often lasts for a short time, the newt must migrate across land on rainy days, to find new living sites. This species has also been found in dark caves, at a depth of 60-70m, near Ben Slimane, Boulhaut, Morocco (Schleich et al 1996). Although P. waltl occurs up to an altitude of 1200m in the Sierra de Loja (Granada), it is rare above 900m in both Europe and Africa (Gasc 1997).

Life History, Abundance, Activity, and Special Behaviors
The reproductive period varies throughout the range, but usually coincides with a wet period. In the vicinity of Leon, mating starts in February and lasts until April. In Extremadura however, mating season lasts from October until May. In Cataluña mating starts in October and lasts until March. Mating takes place in the water. The male holds the female with his front legs around hers. This stage can last hours, up to days. The male then releases one leg and turns his head to the female's caudal direction. The male then releases a spermatophore, and turns the female so her cloaca is near the spermatophore. The sperm mass is taken into the female's cloaca and stored in the spermatheca for fertilization. Two days after fertilisation, the eggs are laid in small groups of 9-20, usually attached to submerged objects or plants. Over the course of 2-3 days, a total of 150 (for young females) up to about 1300 eggs are deposited. The eggs are 1.7 to 2mm in diameter, with a gelatinous envelope of 5-7mm in diameter. Hatching of the 11mm long larvae occurs after 13 days at 18ºC. Metamorphosis occurs at 18ºC after 100-110 days. Under natural conditions, the larvae metamorphose after 3-4.5 months, at a snout-vent length between 53 and 110mm. Some larvae never metamorphose, and get neotenic characteristics. Neoteny was also observed in captivity. In Spain the young reach a length of 14cm after their first year, and 17.5cm after their second. After that, growth slows down and gets irregular. In captivity, these animals reach an age of 8-12 years, although it is suggested that they can live op to 20 years or even longer. The adults feed on aquatic mollusks, worms and insects. When threatened, the skin on the body contracts and pushes the ribs through the yellow-orange warts on the side of the body. The skin in this area is rich in poison glands and the ribs function as poisonous spines to deter the attacker. P. waltl can produce sound when it is picked up (Boehme et al 1999).

Trends and Threats
The species suffers from the same general problems affecting all amphibians, that is, the loss and destruction of spawning sites. As the ponds that the animals live in are often small and temporary, they are difficult to protect, and pollution problems can quickly occur. The species is quite resistant, withstanding high levels of water contamination, and pressure from predators (mainly herons, storks, and the snake Natrix maura). Eating any small moving prey, and even plants and young snakes, the newt can switch diets when the main food source is scarce, and it can also remain for a long time without food. Thus, populations can be relatively stable although they disappear when the biotope is destroyed. Road management has sometimes wiped out nearby populations. The northernmost populations in Spain and Portugal are especially vulnerable, and must be monitored, and their populations protected (Gasc 1997).

Possible reasons for amphibian decline

General habitat alteration and loss

Comments

Featured in Amazing Amphibians on 12 August 2013

References

Boehme, W., Grossenbacher, K., and Thiesmeier, B. (1999). Handbuch der Reptilien und Amphibien Europas, band 4/I:Schwanzlurche (Urodela). Aula-Verlag, Wiesbaden.

Bons, J. and Beniez, P. (1996). Amphibiens et Reptiles du Maroc (Sahara occidental compris). Asociacion Herpetologica Española, Barcelona.

Gasc, J.-P. (1997). Atlas of Amphibians and Reptiles in Europe. Societas Europaea Herpetologica, Bonn, Germany.

Griffiths, R.A. (1996). Newts and Salamanders of Europe. T. and A. D. Poyser, London.

Schleich, H. H., Kastle, W., and Kabisch, K. (1996). Amphibians and Reptiles of North Africa. Koeltz Scientific Publishers, Koenigstein.

Stumpel-Rieks, S. E. (1992). Nomina Herpetofaunae Europaeae. AULA-Verlag, Wiesbaden.

Species Account Citation: AmphibiaWeb 2013 Pleurodeles waltl: Spanish newt <https://amphibiaweb.org/species/4278> University of California, Berkeley, CA, USA. Accessed Nov 24, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 24 Nov 2024.

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