Invertebrates with "spine skin" are which would include animals like

The answer is Echinoderms, which include starfish, sea urchins, sea cucumbers, and sand dollars.

The word Echinoderm is derived from Greek words which mean spiny skin. Their skin usually has spines which can be sharp and pointed out in different directions. The spines offer to echinoderms protection from predators.

Digestion because it removes waste

Molecules called lipids have long hydrocarbon chains that determine the way they act. they can be fats, oils, or hormones, and even exist in our cell membranes