Background:

There are more than 12,000 different animals and plants found in Victoria’s waters with a large number these unique to our southern Australian waters. Our Marine National Park system is designed to protect this diversity and ensure that these species are not lost because of changes brought about by extractive activities such as fishing.

Scientists use classification to sort out the wide range of living things and put them into groups based on their similarities in form and function. Animals and plants that are closely related are assumed to have more features in common and will thus be grouped in the same way. While useful this can also be a problem when species that are genetically close to each other have big differences in their appearance.

Dichotomous keys are tools used to help distinguish between species based on readily observed features. In these keys two alternative choices are evaluated and the next step in the key, or the name of the animal or plant, is based on these choices.