robot fish

Two common approaches appear: some kits use a hybrid solar-and-battery design so sunlight or a battery can power the toy, while other water-activated swimmers rely on internal batteries.

Water-activated technology triggers the swimmer’s motion when the toy is placed in water. In some models the same water contact also produces a visible effect, such as a color change.

Battery requirements vary across models. Examples shown include 1 AAA, 3 AAA, and 2 LR44 alkaline cells; some toys use internal or included batteries.

They’re aimed at young children, with suggested ages listed as both “3 Years and Up” and “5 Years and Up.”

Common features include multi-directional swimming (up to five directions), diving capability (advertised up to 6 ft), lifelike articulated motion, and—on some models—glowing eyes or water-activated color-change effects.