About Pleurodeles waltl Michahelles, 1830
Pleurodeles waltl, commonly called the Iberian ribbed newt, typically has 8 to 10 orange wart-like tubercles running along each side of its body. Its sharp, larger-than-average ribs for a salamander can puncture through its stretched skin via these tubercles. This rib projection acts as a defense mechanism that causes little harm to the newt itself. Iberian ribbed newts generally attempt to flee from predators first, only using this rib mechanism when escape is not possible. This defense can be considered a primitive, rudimentary envenomation system, and it is completely harmless to humans. When the newt pushes its ribs out, it also secretes a milky, viscous poison from special glands across its body. This poison is primarily found on the neck, dorsal and lateral trunk, and the tail. Poison-coated ribs create a highly effective stinging mechanism that injects toxins through the thin skin of a predator’s mouth. The newt’s immune system, collagen-coated ribs, and antimicrobial peptides released from specialized cutaneous glands allow its pierced skin to quickly regrow without infection. Like most amphibians, Iberian ribbed newts hatch in water and breathe through gills during their larval phase. Once they begin growing limbs, they lose their gills and develop the ability to survive both on land and in water. P. waltl is more aquatic than many other European tailed amphibians. While it is fully capable of walking on land, most individuals rarely leave water, typically living in ponds, cisterns, and ancient village wells that were once common across Portugal and Spain. Populations have also been found living in parts of northwestern Africa. The species prefers cool, quiet, deep waters, where it feeds on insects, aquatic molluscs, worms, and tadpoles. During warmer seasons, many of these water sources dry out, so the newts migrate to moist areas under rocks or in vegetated spots. Iberian ribbed newts have been found to have physiological and behavioral plasticity to adapt to different stimuli across varying habitats. In the wild, this amphibian reaches a total length including the tail of 30 cm (12 in), but captive individuals rarely grow larger than 20 cm (7.9 in). Its dorsal side is dark gray, while its ventral side is a lighter gray, with small rust-colored spots at the sites where its ribs can protrude. This newt has a flat, spade-shaped head and a long tail that makes up about half of its total body length. Males are more slender and usually smaller than females. Larvae have bushy external gills and typically paler color patterns than adult newts.
