In the context of discussing the eight sheratzim (creeping creatures) all of whom will render someone who touches them to be tameh, if they are dead – see Sefer Vayikra 11:29-30 – the Gemara relates the following:
Our Rabbis taught: ‘The great lizard after its kinds’ (Vayikra 11:29) includes the arvad, the nefilim, and the salamander. When Rabbi Akiva read this verse he used to say: ‘How great are Your works, O Lord! You have creatures that grow in the sea and You have creatures that grow on the dry land; if those of the sea were to come up upon the dry land they would immediately die, and if those on the dry land were to go down into the sea they would immediately die. Similarly, You have creatures that grow in fire and You have creatures that grow in the air; if those in the fire would ascend to the air they would immediately die, and if those in the air would descend to the fire they would immediately die. How great are Your works, O Lord!’
Salamander is the common name applied to approximately 500 species of amphibians with slender bodies, short legs, and long tails. The common (or “fire”) salamander, salamandra salamander, lives in and around rivers and swamps in Israel and around the world. There is a superficial resemblance to lizards, but they have no scales and their skin is covered with moist mucous. This salamander is mentioned in the same context as the mythical “salamandra of fire,” which is described in the Midrash. Some suggest that Rabbi Akiva’s reference is to the common salamander, which was seen as fire-proof because of its moist body; however, the description of this creature in the Midrash cannot be reconciled with that idea.
The Ḥatam Sofer suggests that the salamander mentioned by Rabbi Akiva lives in places where there are active volcanoes, and only in these climates can such creatures survive.