have fertilisation induced through hormonal stimulation. Another advantage to this species is their development is slow, so all the key stages of ontogenesis can be observed, from the oocyte to swimming tailbud embryos or larvae. Studies looked at the newts' ability to regenerate (which was faster in space overall, and up to two times as fast in early stages) as well as the stages of development and reproduction in space. On the ground, studies of hypergravity (up to 3g) on P. waltl fertilisation have also been conducted, as well as on the fertility of the space-born newts once they arrived back on Earth (they were fertile, and without problems). Similar microgravity experiments have also been conducted for other species, namely the frog species Hyla japonica, and no effects on long term health are similarly observed. Regeneration Pleurodeles waltl is a model system for the study of adult regeneration. Similar to other salamanders, P. waltl are animals that can regenerate lost limbs, injured heart tissue, lesioned brain cells in addition to other body parts such as the eye lens and the spinal cord. The 20 Gb genome of P. waltl has been sequenced to facilitate research into the genetic basis of this extraordinary regenerative ability. See also List of Mir Expeditions Animals in space References External links Spanish ribbed newt - Pleurodeles waltl, BioFresh Cabinet of Freshwater Curiosities. Caudata Culture: Pleurodeles waltl Livingworld.org: Pleurodeles waltl Bizarre newt uses ribs as weapons, BBC Earth News. Animal models Newts Amphibians of North Africa Amphibians of Europe Amphibians described in 1830