Sharp-ribbed salamander (Pleurodeles waltl)

Also known as the sharp-ribbed newt, the sharp-ribbed salamander (Pleurodeles waltl) is one of Europe’s largest salamander species ⁽³⁾. It is stout-bodied, with rough, grey-brown skin covered in irregular dark spots. On each side of the body there is a row of between seven and ten, orange, wart-like spots ^{(2) (3) (4) (5)}. The tail of the sharp-ribbed salamander is long with a narrow fin, perfectly adapted for swimming. This species has a broad head which is flattened horizontally, and the eyes are relatively small and have moveable eyelids ^{(2) (4) (5)}. 

The male sharp-ribbed salamander has a longer tail than the female. The male also develops patches on its limbs during the breeding season, to help maintain a grip on the female during copulation ^{(2) (5)}.

Individuals of this species from north Africa are smaller than those from European populations ⁽²⁾.

Also known as

Sharp-ribbed salamander, Spanish ribbed newt.

French

Pleurodèles De Waltl, Triton D’espagne, Triton De Waltl.

Spanish

Gallipato.

Size

Male length: up to 31 cm ^{(2) (3)}

Female length: up to 28 cm ⁽²⁾

As it is a highly aquatic species, the breeding of the sharp-ribbed salamander coincides with the rainy season, the timing of which differs throughout its range ^{(1) (2)}. Mating occurs within the water body, with the male holding the female from underneath with their limbs entwined. The pair may remain in this position for days. During mating, the male salamander releases a package of sperm cells, which are taken up by the female and stored for fertilisation ^{(2) (7)}.

After two days, the female sharp-ribbed salamander will lay between 800 and 1,500 eggs in vegetation or underneath stones in the water ^{(1) (2) (3)}. The tiny eggs are usually laid in groups of between 9 and 20, and each egg has a protective jelly-like layer up to three times larger than the embryo itself. The eggs hatch after 13 to 18 days, with metamorphosis occurring after 3 months of life, when the larvae take the adult form ⁽²⁾.

A voracious predator, the sharp-ribbed salamander will eat most attainable prey within its range, including molluscs, worms, insects, other amphibians and small fish ^{(2) (3) (5)}. It is a very resilient species and is able to last long periods of time without eating, changing its diet depending on the availability of prey ⁽²⁾. Most of the activity of this species takes place at night ^{(3) (5)}.

The sharp-ribbed salamander has a highly specialised defence mechanism, from which it receives its common name. When threatened, it will convulse, forcing its pointed ribs through the orange spots on the sides of its body. This skin is poisonous, and therefore when the ribs push through, sharp, contaminated spines are created which can penetrate the mouth of the predator, causing high levels of pain ^{(2) (4) (6) (8) (9)}. The sharp-ribbed salamander may also slap its tail at the predator, drawing attention away from other areas of the body, which unlike the tail, are not expendable ⁽⁴⁾.

The sharp-ribbed salamander is distributed throughout non-mountainous regions of Spain, Portugal and northern Morocco ^{(1) (2) (4) (5) (6)}.

The sharp-ribbed salamander is a lowland species, rarely found higher than 900 metres above sea level. It typically inhabits small ponds, lakes, calm brooks, or occasionally ditches, often in scrub, cultivated land or woodland ^{(1) (3)}.

This species is seldom found on land, instead preferring to hide underneath stones, mud or the plentiful aquatic plants within its aquatic habitat ^{(1) (5)}. The ponds occupied by the sharp-ribbed salamander frequently dry out during the warmer summer months, and individuals therefore have to burrow into mud to await the next rainfall ⁽⁵⁾.

The sharp-ribbed salamander is classified as Near Threatened (NT) on the IUCN Red List ⁽¹⁾.

Crayfish (Procambarus clarkii) have been introduced into the wetlands inhabited by the sharp-ribbed salamander. The crayfish eat the eggs and larvae of this species, which has resulted in a drastic reduction in population size ^{(1) (10)}. There has also been a decline in suitable habitat due to water drainage, pollution, eutrophication and construction of roads and buildings for the tourism industry in coastal areas ^{(1) (2)}.

Road accidents are also a serious danger to the sharp-ribbed salamander when travelling through its terrestrial habitat ⁽¹⁾.

The sharp-ribbed salamander occurs in many protected areas in Spain and Portugal. However, many of its populations are unmonitored ⁽¹⁾. This species is listed on Appendix III of the Bern Convention, which provides guidelines to protect the flora and fauna of Europe ⁽¹¹⁾. It is also protected by national legislation in Spain ⁽¹⁾.

Within the sharp-ribbed salamander’s range, there are captive breeding programmes attempting to increase population numbers in safe spawning areas. In addition, some habitat restoration has been attempted, with the view to create protected areas for future generations of sharp-ribbed salamanders to thrive ⁽¹⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more about amphibian conservation:

• IUCN/SSC Amphibian Specialist group:
  http://www.amphibians.org/
• Gascon, C., Collins J.P. Moore, R.D., Church, D.R., McKay, J.E. and Mendelson III, J.R. (2007) Amphibian Conservation Action Plan. IUCN/SSC Amphibian Specialist Group, Gland, Switzerland and Cambridge, UK. Available at: 
  http://www.amphibianark.org/pdf/ACAP.pdf
• Amphibian Ark:
  http://www.amphibianark.org/
• AmphibiaWeb:
  http://amphibiaweb.org/cgi/amphib_query?where-genus=Pleurodeles&where-species=waltl

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Eutrophication

A process in which a water body is enriched with excessive nutrients (such as nitrogen and phosphorus) resulting in the excessive growth of aquatic plants and the depletion of oxygen, creating unfavourable conditions for other organisms, such as fish.

Fertilisation

The fusion of gametes (male and female reproductive cells) to produce an embryo, which grows into a new individual.

Larva

Immature stage in an animal’s lifecycle, after it hatches from an egg and before it changes into the adult form. Larvae are typically very different in appearance to adults; they are able to feed and move around but are usually unable to reproduce.

Metamorphosis

An abrupt physical change from the larval to the adult form.

Molluscs

A diverse group of invertebrates, mainly marine, that have one or all of the following: a horny, toothed ribbon in the mouth (the radula), a shell covering the upper surface of the body, and a mantle or mantle cavity with a type of gill. Includes snails, slugs, shellfish, octopuses and squid.

Spawning

The production or depositing of eggs in water.

1. IUCN Red List (October, 2011)
   http://www.iucnredlist.org/
2. AmphibiaWeb - Pleurodeles waltl (October, 2011)
   http://amphibiaweb.org/cgi/amphib_query?where-genus=Pleurodeles&where-species=waltl
3. Gibson, C. (2010) Wild Animals. Dorling Kindersley, London.
4. Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.
5. O’Shea, M. and Halliday, T. (2001) Reptiles and Amphibians. Dorling Kindersley Limited, London.
6. Stebbins, R.C. and Cohen, N.W. (1995) A Natural History of Amphibians. Princeton University Press, Princeton, New Jersey.
7. Mathur, R. (2009) Animal Behaviour. Rastogi Publications, Meerut, India.
8. Duellman, D.E. and Trueb, L. (1986) Biology of Amphibians. Johns Hopkins University Press, Baltimore, Maryland.
9. Marshall Cavendish Corporation (2004) Encyclopedia of the Aquatic World. Marshall Cavendish, New York.
10. Gherardi, F. (2007) Biological Invaders in Inland Waters: Profiles, Distribution and Threats. Springer, Dordrecht, Netherlands.
11. Council of Europe: Bern Convention (November, 2011)
    http://conventions.coe.int/Treaty/EN/Treaties/Html/104.htm