You searched for: “invertebrates”
invertebrate (s) (noun), invertebrates (pl)
A type of animal that does not have a backbone: "Invertebrates are extraordinarily varied; many are microscopic, but the largest are over 33 feet (10 meters) long."

"There is no such thing as a typical invertebrate, and many of the phyla have very little in common with each other."

"The most simple invertebrates do not have heads or brains, and they usually depend on internal fluid pressure to keep their shapes."

"Those invertebrates at the opposite end of the 'simple' species have well-developed nervous systems, as well as, elaborate sense organs, including complex eyes and they also have external body cases, or exoskeletons, with legs that bend by means of flexible joints; however, they never have internal skeletons made of bone."

—This information was compiled from data in the
Smithsonian Natural History, Dorling Kindersley Limited;
New York; 2010; page 248.
This entry is located in the following unit: vers-, vert-, -verse, -version, -version, -versation, -versal, -versary, -vert, vort-, vors- (page 9)
insecto-, insect-, insecti- +
(Latin: a bug; literally, "cut into," from insectum, with a notched or divided body; literally, "that which is cut up, segmented" [as the bodies of the first invertebrates to which the term was applied or appeared to be])