‘Micro Monsters: Outdoors’
‘Micro Monsters: Outdoors’ by Sabrina Crewe
1. Tardigrades, or water bears, can survive in extreme environment. They love water, but if the water dries up, so do they. Tardigrades simply tuck in their head and legs, curl up and form a wrinkly bundle called a tun. They stay like that until they get watered, and then they start to move again.
Tardigrades eat other micro-animals and moss. Otherwise they have no effect on the garden or on people.
2. Hydras (水螅) live in shallow water on stones, twigs or even just attached to the water surface. They can’t swim. Unless a current carries them along, hydras have to inch along a surface, a bit like a worm.
Scientists believe hydras may be able to make new cells indefinitely, as they appear not to age. In theory, they could live forever if not threatened by predators or other forces.
3. Amoebas live everywhere in water and on the bottom of ponds, fountains and puddles. Amoebas are one-celled protozoa. When it is ready to reproduce, the amoeba’s nucleus divides into two and forms two separate and identical cells. Some amoebas can be useful. They help control algae and bacteria, and they purify water in ponds and other watery places.
4. Cyclops (劍水蚤) is a copepod, a tiny crustacean. They five pairs of legs, a large pair of antennae and one big eye smack in the middle of their heads. Cyclops live in all types of water — -even just a few drops are enough to be home to cyclops.
Cyclops are food for many bigger animals, but they are hard to catch. When a cyclop senses danger, a signal goes to its antennae and its legs. These can propel them about 50cm in a second. That’s like you jumping about a kilometre.
5. Fungi are living organisms, like plants, except they can’t make their own food. Fungi weave webs of hyphae, tiny threads that feed off plants and sprout fruiting bodies, pods full of spores.
Fungi live on living and dead things, such as the leaves, flowers and roots of trees and smaller plants, including crops.
Powdery mildew can harm plants, but most fungi are good for the garden. They break down dead matter as they feed on it, turning it into nutrients for the soil. So far, more than 45000 kinds of fungi have been identified in soil.
In tropical gardens, there are fungi that invade the bodies of ants and other insects. They grow on their host in the form of toadstools or hairs. Bit by bit, the fungi replace their victim’s cells with their own, until they kill it.
6. Didinium is one of a group of organisms called ciliates (纖毛蟲) . Ciliates are protozoa, a type of protist, which has only one cell. Protozoa are not really animals, but they behave like them by hunting prey. Ciliates live in water in ponds, puddles and drops of water in garden soil.
Didinium mostly eat other ciliates. The didinium will digest its food in a few hours and be ready to go hunting again. If the didinium can’t get any food for a while, it covers itself in a shell and goes dormant until it senses some new prey.
