2006-08-20 18:15:11 · 18 answers · asked by Anonymous in Science & Mathematics ➔ Biology
The smallest animals on Earth are various species of microscopic roundworms. Adults in many species are less than 1/10th of a millimeter in length, smaller than many single-celled organisms.
2006-08-20 21:44:08 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Answer at the end of this post (*great* question, BTW) ... but first, to clear up some misinformation:
Bacteria are NOT animals. (Not members of the kingdom Animalia.)
Insects ARE animals. (Members of the kindom Animalia.)
One question is whether the protozoans are classified as part of kingdom Animalia or not. These are the single-celled organisms that includes amoebas, paramecium, sporozoa, etc. (but not bacteria). They are usually classified in the kingdom Protista, although I found many web sites that still list them as belonging to Animalia. I believe they are wrong ... the newer classifications of life forms keeps protists and protozoans separate from animals ... i.e., by definition, ANIMALS ARE MULTI-CELLULAR. Wikipedia and Britannica definitely say the the protozoans are definitely NOT animals (see source #1). However for some discussion on this issue, see source #2.
The other question is whether we consider only fully formed adult animals. I would say yes, or else you then have to consider a newly fertilized ovum (a zygote) as an animal. (Incidentally, I've seen some sites that list the smallest insect egg as that of Zenillia pullata ... but that is relative to the size of the female adult.)
The smallest adult multi-cellular animal appears to be an insect, the blind, wingless male of the species of parasitic wasp Dicopomorpha echmepterygis (see source #3), at a tiny 139 micrometers. Discovered in 1998, it has replaced the old record-holder Megaphragma caribea (170 micrometers).
2006-08-21 07:58:45 · answer #2 · answered by secretsauce 7 · 3⤊ 0⤋
Although the definition of an "animal" can be a bit fuzzy, maybe the water bear could be called the worlds smallest animal.
It has to be at least one of the most amazing animals on earth
2006-08-21 01:39:27 · answer #3 · answered by tempus808 1 · 0⤊ 0⤋
The smallest animal in the world would depend on your definition of an animal. This site lists a number of inportant points so I am going to go with their answer...
--> Megaphragma caribea at 0.12mm
2006-08-23 14:23:04 · answer #4 · answered by Anonymous · 0⤊ 0⤋
The baby of the smallest animal ;-)
2006-08-21 02:58:36 · answer #5 · answered by jay Z 4 · 0⤊ 0⤋
Smallest animal on earth is ofcourse a squirell as ants and beetles are insects not animals...and i say sparrow its again a bird not a animal...so squirell is smallest
2006-08-21 01:22:36 · answer #6 · answered by hotgy4999 3 · 0⤊ 1⤋
The smallest animal (living organism) is single cell animal. It may include amoeba, bacteria, fungus etc.
2006-08-21 01:34:11 · answer #7 · answered by dinu 3 · 0⤊ 1⤋
Single-cell organisms are not animals, but insects are. I'm sure it's some kind of insect, but I couldn't tell you which one.
2006-08-21 01:43:46 · answer #8 · answered by enaronia 2 · 0⤊ 0⤋
archae bacteria...virus are not animals since they don't contain both DNA and RNA at the same time...most scientists consider virus as not living...the composition of matter are the cells...its a pleasure helping you...
2006-08-21 01:27:39 · answer #9 · answered by TIMEPASS 3 · 0⤊ 0⤋
I know it is a 4 legged.
2006-08-21 03:49:28 · answer #10 · answered by Sathish 2 · 0⤊ 0⤋