Introduction & Physical Description
Pleurodeles waltl is a robust newt, with thick limbs, tail, and abdomen. P. waltl are large newts, and can reach up to 12 inches in total length, with averages around 8-9 inches. The tail is as long, sometimes longer than the body from snout to vent, and can become highly compressed in the lateral direction. Males possess longer, and more laterally compressed tails than females, and thicker forearms. Males are also slightly smaller than females, develop nuptial pads on the front legs, and a reddish-orange hue along the body during the breeding season. Males and females are similar in appearance, and often times difficult to differentiate. The coloration is rather variable, but generally consists of a light or dark gray background covered with blurry, irregular blotches of darker gray or black. The size and abundance of the blotches varies for different individuals, and some may instead be one solid color. Others may possess light colored blotches, and still others may have markedly contrasting blotches. The ventral background color is lighter than the dorsum, but possesses the same blurry dark blotches. Some individuals may lack the dark blotches altogether, and rarer individuals may be a solid yellowish-green color. The head is flattened, and the eyes are almost on the top of the head. The flattened head is thought to be an adaptation acquired to better execute quick escapes between flat rocks, and the purpose of the eye position may be to aid in detecting movements at the waters surface. There are two rows of yellow-orange dots running down each side of the inconspicuous dorsal ridge, that typically run the length of the abdomen, between the fore and hind limbs, but sometimes shorter. The dots are paratoid glands, and mark the position of the rib tips. These paratoid glands are very pronounced in some, and highly reduced in others. Just under the paratoid glands are the tips of the ribs, which are capable of rupturing the paratoid glands and piercing through the skin by contraction of the body. This is an excellent defense mechanism, for when an animal attempts to take a bite of a Spanish ribbed newt, not only does it get a mouth full of poison from the ruptured glands, it may be stabbed by the piercing ribs. The piercing ribs apparently do no cause permanent damage to the newts.

Synonymy

Vernacular Synonymy: Spanish Ribbed Newt, Sharp Ribbed Newt, Ribbed Newt, Spanish Newt, Iberian Ribbed Newt

Distribution & Natural Habitat of Pleurodeles spp.

Pleurodeles waltl are large newts, capable of reaching up to 12 inches in total length, and averaging around 8-9 inches. P. waltl tend to nip at each other, and during feeding times can be blatantly violent. Because of their impressive size and voracious feeding habits, it is necessary to house these newts in large tanks with plenty of individual room. P. waltl are found at considerable depths in the wild, so a tall and wide tank is appropriate for this species. 

Although P. waltl are tolerant of warmer temperatures for periods of time, the water temperature should be kept within the 68°F- 73°F range during the warmer months. During the winter months, temperatures of 55°F-63F° are acceptable. 

P. waltl should be housed in a semi-aquatic or aquatic tank with a large percentage of deep, cool water. Personally, I have kept a colony of adults fully aquatic for a few years, and their offspring in a semi-aquatic setup with a small land area. It has been my experience that juveniles sometimes "rest" halfway exposed on the land area. Filtration can consist of a carbon and sponge insert filter, or a canister type biological filter for larger tanks. P. waltl prefer slower moving water bodies, so any filtration used should not create a strong disturbance. Filter outputs can be positioned to point toward the side of the tank, or can be blocked with heavy vegetation or rocks. Most new filter models come equipped with adjustable outputs, which should be set on medium or low. If filtration is omitted, a partial water change (10%-20%) should be administered weekly or biweekly, depending on the size of the tank and number of inhabitants. Although not practical in most situations, a water area of 3 feet or more is ideal for P. waltl. However, this is a rather adaptable newt, and a water level of 10+ inches should suffice in captivity. P. waltl are sensitive to water chemistry, and a sudden change from aquatic to terrestrial behavior may indicate a problem with the water quality. It is recommended to keep a freshwater test kit on hand, and regularly check the pH, ammonia, nitrite, and nitrate levels. Aquatic plants can be included, but in general, P. waltl can do with or without heavy vegetation. Large, mossy rocks, potted plants, or driftwood protruding from the water are typically used for land areas, as P. waltl rarely emerge onto land for long periods of time, especially in captivity. However, some may emerge halfway and "rest" in that position for a period of time. Hiding places can consist of stacked rocks with plenty of small, dark crevices, small rock caves, stacked driftwood, etc. Bare bottom tanks are sometimes used with P. waltl, but medium-sized gravel is acceptable for substrate, as well. If a bare bottom tank is used, then decaying organic matter (i.e. feces, shed skin, uneaten food, etc.) should be siphoned out of the tank weekly or biweekly, and sufficient biological filtration should be included. The tank should also have a secure, preferably screen, lid, as most newt species can climb glass and escape when determined enough to do so. See article 0020 - Captive Habitats: Ideas, Instructions, and Examples and the Captive & Wild Habitats section of the Photo Gallery.

Juveniles are also highly aquatic, and can be housed identically to the adults. To avoid injury, smaller newts should not be housed with adults.

As with all amphibians, tap water should be treated with a water conditioner or primer prior to the introduction of amphibians. Never use plain tap water, de-ionized, distilled, or reverse osmosis water alone with amphibians. Also, the tank should be cycled (nitrogen cycle) prior to the introduction of amphibians, and water chemistry should be within healthy range. See article 0006 - Water Quality and Amphibians and article 0009 - Introduction to the Nitrogen Cycle for more information about water quality and the importance of the nitrogen cycle. 

Breeding Behavior

Mating takes place in the water, and in a typical season, P. waltl will begin breeding from March to June, usually during the onset of Spring. Unusually warm winters may prompt a second breeding season, or the continuation of the breeding season through the remainder of the year. Amplexus consists of the male swimming under the female, and grasping her front legs with his. They may stay locked in this position for several minutes, sometimes more than an hour. Some have reported amplexus lasting for several hours. After a time, the male will turn around and deposit a spermatophore near the females cloaca. Sometimes the male will attempt to position the female over the spermatophore. Uninterested females may thrash about the tank violently to force the male to release her, which may or may not work.

In captivity, the breeding season can be simulated by a slight rise in temperature, and/or flooding of the tank. Some individuals may be prompted to breed by simply raising the water level several inches. A rain chamber can also be used to simulate the rainy season and flood the tank. Established colonies will breed consistently with only the subtle seasonal temperature changes incurred in an insulated building, such as a house, and with no additional help from their keepers.

Between 200 and 1300 eggs are produced in a season, depending on the age and size of the female, and are usually deposited in small clumps of 5-20 eggs. Eggs may be attached to submerged vegetation, rocks, wood, or simply strewn about the ground. In captivity, it is not uncommon for the female to simply deposit them on the ground, where they may be easily consumed by other newts in the tank, or even the mother. 

Eggs and larvae should be kept around 69°F- 73°F to simulate the summer temperatures in the wild. After metamorphosis, the young are mostly aquatic, like the adults, but may leave the water periodically for short periods of time. The coloration is identical to the adult pattern. New morphs grow very quickly when fed often, and can reach close to adult size in less than a year. Although not very common, some neotenous individuals have been noted in captivity, and in the wild. 

In captivity, young females may produce infertile eggs periodically. The first fertile clutch produced by young females are often smaller than normal, as well, and sometimes mistaken for infertile eggs.

Feeding Pleurodeles waltl

During feeding time, morphed individuals tend to frenzy at the scent of food, and often accidentally grab at, and bite nearby newts. Large newts are capable of inflicting serious wounds, even taking off limbs of other newts, and for this reason, ample territory is required for P. waltl. Also, turning off filters during feeding time reduces the frenzying behavior significantly, as the newts can pinpoint the scent of food easier. See article 0002 - Amphibian Foods and Feeding Tips for more information on commonly available food items.