what is the size of the largest one?
length of 29.9 meters
Blue whale
Reaching a maximum confirmed length of 29.9 meters (98 feet) and weight of 173 tonnes (190 tons), it is the largest animal known to have ever existed. The blue whale’s long and slender body can be various shades of grayish-blue dorsally and somewhat lighter underneath.
what characteristics do all the organisms in the animal kingdom share Animals are eukaryotic, multicellular, heterotrophic, respire aerobically what is meant by the third feature? A heterotroph  is an organism that cannot produce its own food, instead taking nutrition from other sources of organic carbon, mainly plant or animal matter. can you give example of such species? All animals and fungi, ome bacteria and protists, and many parasitic plants. regarding the first one; how are they classified? Insecta, Pisces, Amphibia, Aves, and Mammalia. which is the largest of it? The blue whale and the smallest? Myxobolus shekel
wiki:1554441
Blue whale [SEP] Introduction
The blue whale ("Balaenoptera musculus") is a marine mammal belonging to the baleen whale suborder Mysticeti. Reaching a maximum confirmed length of 29.9 meters (98 feet) and weight of 173 tonnes (190 tons), it is the largest animal known to have ever existed. The blue whale's long and slender body can be various shades of grayish-blue dorsally and somewhat lighter underneath. There are currently five subspecies of blue whale, recognized by the Society for Marine Mammalogy's Committee on Taxonomy: "B. m. musculus" in the North Atlantic and North Pacific, "B. m. intermedia" in the Southern Ocean, "B. m. brevicauda" (the pygmy blue whale) in the Indian Ocean and South Pacific Ocean, "B.