Endangered species
The IUCN redbook of endangered species lists the following numbers of known species
Vertebrates
5,490 mammals
9,998 Birds
9,084 Reptiles
6,433 Amphibians
31,300 Fish
Invertebrates
1,000,000 Insects
85,000 Molluscs
47,000 Crustaceans
2,175 Corals
102,248 Arachnids
165 Velvet Worms
4 Horseshoe Crabs
68,658 Others
Plants
16,236 Mosses
12,000 Ferns and Allies
1021 Gymnosperms
281,821 Flowering Plants
4053 Green Algae
6081 Red Algae
Fungi and Protists
16,236 Lichens
12,000 Mushrooms
1021 brown Algae
Total number of known species = 1,740,330
Source of data - IUCN Red List of Threatened Species. Version 2010.1 (updated 11 March 2010).
Website: http://www.iucnredlist.org
Page: Table 1: Numbers of threatened species by major groups of organisms (1996–2010)