“Starfish are fish.”

It's easy to assume that a creature with "fish" in its name, found living in the ocean, must indeed be a fish. However, this common assumption about starfish, or sea stars as they are often more accurately called, is a classic example of how everyday language can mislead us about the natural world. The myth likely originated from their aquatic habitat and the "fish" label, which has stuck for centuries despite scientific understanding.

Scientifically speaking, starfish are not fish at all. They belong to a completely different phylum called Echinodermata, which includes other fascinating marine animals like sea urchins, sand dollars, and sea cucumbers. Unlike true fish, which are vertebrates with gills for breathing, scales covering their bodies, and fins for propulsion, starfish possess none of these characteristics. They do not have a backbone, scales, or fins. Instead, they breathe through small skin gills and move across the seafloor using thousands of tiny, suction-cup-tipped tube feet located on their undersides.

The persistent belief that starfish are fish stems primarily from their misleading common name and their aquatic environment. When people see these star-shaped creatures underwater, the "fish" part of their name naturally leads to a categorisation alongside other finned ocean dwellers. However, understanding their unique biology reveals a creature far more distinct, showcasing the incredible diversity of life beneath the waves and reminding us that names can sometimes be deceiving.