The horse shoe crab has a hard outer surface carapace which has the shape of a horse shoe.
It has book lungs which come in 5 sets. The lungs are usually found on the ventral side of the crab.
The book lungs acts as gills which is used in breathing when the horseshoe crab is in water . The book lungs also helps the crab to breathe on land for a certain period of time provided the lungs are moist.
when you are finished using a light microscope or any microscope in general you always need to put the cover back on it. Mostly, to protect it from any harmful bacteria, light etc. and to keep it clean and, from collecting dust.
Because if you take care of your body/organs by exercise and good diet then your bidy will stay healthy without sickness which results in longer life span
