Isaac and Olivia are fire-bellied newts. More specifically, they are probably Chinese fire-bellied newts, also known as oriental fire-bellied newts or a dwarf fire-bellied newts. Their proper scientific name is Cynops orientalis.
The other main type of fire-bellied newt is a Japanese Fire-bellied Newt (C. pyrrhogaster), but these newts are a bit bigger and a slightly different shape than Isaac and Olivia
The color of their backs is black, and the color of their bellies is orange with red spots. At the moment their skin is very smooth, but will get rougher as they get older. They have flat bodies with four legs and a tail. Their feet each have three toes.
They like to live in areas with cool, still water with lots of green plants, and flat rocks and bark the they can climb up onto. They like to have dark cool areas where they can hide away. They don't like it too hot or too cold so the temperature in their tank needs to stay between 18 and 22 degrees C. The tank needs to be cleaned every two to three weeks.
Isaac and Olivia like their food to be alive! So they eat small fruit flies and worms from the pet store. They get fed every second or third day.
At the moment they are 6 months old and currently about 3.5 cm long. When they grow up, they could grow to about 10 cm but could even be as big as 12 to 15 cm long. They should live to 10 to 30 years old and may even live to the ripe old age of 60 years.
It's not a good idea! Their skin could make you sick! When they are upset, they secrete a toxin which can cause numbness and dizziness, particularly if you have any cuts or scratches on your hands. If any of it gets into your mouth and you swallow it, you would probably need to go to hospital.