What do you call a fish without eyes?

The classic riddle about a fish without eyes relies on a simple yet effective humor mechanism: wordplay. The joke cleverly removes the letter "i" from the word "fish" to represent the absence of "eyes," creating the phonetic sound "fsh." It's a playful twist on spelling and pronunciation that appeals to our linguistic understanding and often elicits a groan before a chuckle. This kind of pun-based humor is a staple in many joke categories, especially dad jokes, because of its straightforward and often unexpected cleverness.

While the joke itself is a linguistic trick, the concept of fish without eyes isn't entirely imaginary. In the real world, there are fascinating creatures known as blind cavefish. These fish, like the Mexican blind cavefish (Astyanax mexicanus), have evolved in perpetually dark environments such as underground caves and deep ocean channels where eyesight is unnecessary. Over generations, they've lost their functional eyes, conserving energy that would otherwise be used for vision and instead developing heightened senses like smell and a sensitive lateral line system to navigate and find food in their lightless habitats. So, while the "fsh" is a silly pun, actual fish have indeed adapted to life without their "i's."