Scientists have described well over over 1.7 million of the world's species of animals, plants, insects and algae.

Below you'll find a list that gives the number of species known in the world for each major category of living creatures and organisms.

The numbers most accurately represent all living species of mammals, birds and coniferous plants. Only for those groups have scientists almost completely identified all the world's species.

Biologists have yet to describe many species of plants, invertebrate animals and lichens. So the number of these species known to science increases substantially every year.

The greatest species diversity exists among insects, which account for about one million of the earth's species known to science. Mammals make up one of the smallest groups, with just 5,513 members.

Altogether the earth's oceans, lakes, continents and islands support over 66,000 identified species of vertebrate animals and more than 307,000 species of plants.

How many species known to currently exist in the world. Category Species Totals Vertebrate Animals Mammals 5,513 Birds 10,425 Reptiles 10,038 Amphibians 7,302 Fishes 32,900 Total Vertebrates 66,178 Invertebrate Animals Insects 1,000,000 Spiders and scorpions 102,248 Molluscs 85,000 Crustaceans 47,000 Corals 2,175 Others 68,827 Total Invertebrates 1,305,250 Plants Flowering plants (angiosperms) 268,000 Conifers (gymnosperms) 1,052 Ferns and horsetails 12,000 Mosses 16,236 Red and green algae 10,386 Total Plants 307,674 Others Lichens 17,000 Mushrooms 31,496 Brown algae 3,127 Total Others 51,623 TOTAL SPECIES 1,730,725

The species totals do not include domestic animals such as sheep, goats and camels. Nor do they include single-celled organisms such as bacteria.