1. Immortal JellyfishThe Turritopsis Nutricula is able to revert back to a juvenile form once it mates after becoming sexually mature
Marine biologists say the jellyfish numbers are rocketing because they need not die...
Dr Maria Miglietta of the Smithsonian Tropical Marine Institute said: "We are looking at a worldwide silent invasion."
The jellyfish are originally from the Caribbean but have spread all over the world.
Turritopsis Nutricula is technically known as a hydrozoan and is the only known animal that is capable of reverting completely to its younger self.
3. Tree Weta
* Hemideina broughi (Buller, 1896) West Coast bush weta - overlaps with the Wellington tree weta on the West Coast.
* Hemideina crassidens (Blanchard, 1851) Wellington tree weta - Wellington, the Wairarapa, the northern parts of South Island, and the West Coast.
* Hemideina femorata Hutton, 1898 Canterbury tree weta - Canterbury.
* Hemideina maori (Pictet & Saussure, 1891) Mountain stone weta - the drier areas of the central South Island High Country. It abandoned life in trees millions of years ago in favour of crevices and cavities under rocks.
* Hemideina ricta Hutton, 1898 Banks Peninsula tree weta - Banks Peninsula.
* Hemideina thoracica (White, 1842) Auckland tree weta or tokoriro - found throughout the North Island apart from the Wellington-Wairarapa region.
* Hemideina trewicki Morgan Richards, 1995 Hawke's Bay tree weta - Hawke's Bay.
4. Tardigrades (Water Bears)
5. East African Giant Snail
The Giant African Land Snails (Achatina sp.) are molluscs and make ideal pets as they are easy to look after. They can live for several years and grow up to 20cm in length. The snails are most active during the night (they are nocturnal).
These snails can be housed in a variety of containers, depending upon the size and number of snails that you have. A good container is a glass or plastic aquarium tank. These type of containers allow easy cleaning and you will be able to watch your snails through the sides. The snails like to burrow, so when you have your tank, fill it with several centimeters of peat-free compost and a large piece of bark. (If you collect the bark yourself make sure that you soak it in water overnight to remove any nasty chemicals). Make sure that the substrate is kept moist at all times, but not soggy. Leaf litter and moss are also good at keeping the soil damp. The tank should be kept at 20-25°C, which means that a small heat mat or pad is necessary during the winter months. The tank should be kept moist and a plant spray is ideal, providing it hasn't been used with chemicals as these could harm your snails.
If snails are not kept in correct conditions they may seal the aperture (opening) to their shell and wait for conditions to improve. If this happens you should make sure you are keeping the snails correctly. Once you have resolved these housing issues you can encourage the snails to open up again by bathing them in luke-warm water.