The Fish That Knew

The wrasse was the only fish left worth watching. Everything else in the tank just hung in the water like it was waiting for a bus.

"It keeps coming back to that side," Maya said. She was lying on the carpet with her chin on her hands, eye level with the glass. "The side near the filter."

"That's where the light is," said Soren. He was checking the salt level, because that was the one job his cousin had texted him about. Keep the salt right or the fish die. No pressure.

"No. It's looking at itself." Maya tapped the glass. The little blue and black fish darted, then came back. "Watch. It does the thing again."

Soren looked. The wrasse swam up to the corner where two panes of glass met, and in the corner there was a faint doubled reflection, a ghost of a fish facing the real one. The wrasse tilted. It turned its body sideways and held there, almost vibrating.

"Fish do that to other fish," Soren said. "It thinks it's another wrasse. Cousin Reza said they're territorial."

"Then why isn't it fighting?"

That stopped him. A territorial fish, seeing a rival, should flare or charge or flee. This one was just holding its body at an angle, the way you'd turn to see the back of your own shirt in a changing room.

"Get the little mirror," Maya said. "The one from the bathroom drawer."

Soren got it. It was a round dentist's mirror Reza used to check the back of the tank for algae. He clipped it to the inside of the glass, facing in, where the wrasse could see it.

The wrasse found it in about four seconds.

It charged. Mouth open, fins out, straight at the mirror. Then it veered off. Came back. Charged again. Veered.

"Okay, so it does think it's a rival," Soren said. He felt a small relief, because that fit. That made sense. Fish were not supposed to be complicated.

"For now," said Maya.

They watched for twenty minutes. The charging slowed. Then it stopped. The wrasse began doing strange swimming in front of the mirror, loops and rolls, the kind of thing that has no reason if you're trying to scare an enemy. It would do a move, then hold still and look. Do a move, hold still, look.

"It's testing," Maya said quietly. "It moves, the other one moves the same. It's checking if the other one copies."

Soren had stopped pretending to do the salt. "That's what I would do," he said. "If I wasn't sure whether something was me."

Maya rolled onto her back and stared at the ceiling. Then she sat up fast.

"There was a study," she said. "Reza had it bookmarked. On the laptop. About these exact fish."

They found it. The laptop was still logged in. The title used a word neither of them said out loud at first: self-recognition. There were photographs of cleaner wrasse with a small colored mark placed on their throats, somewhere the fish could not see without a mirror.

Soren read the part about what the marked fish did. He read it twice to be sure.

"It went and scraped the mark off," he said. "On the sand. On a rock. The exact spot where the mark was. Not a random spot. The spot it could only see in the reflection."

Maya was already moving. "We need a mark."

"We are not coloring Reza's fish."

"Not coloring. Watching." She pointed at the wrasse, which was still looping in front of the mirror. "It already has one. Look at its side."

Soren leaned in. On the wrasse's flank, near the gill, there was a pale patch where a scale had come loose, a small whitish blot. Not painted. Just a scuff from tank life. Something the fish could not see unless it was looking at its own reflection.

"Watch where it goes," Maya said.

They watched. The wrasse held in front of the mirror, tilted, the way it had the very first time, turning its marked side toward the glass. It held there a long moment.

Then it broke away, dropped down to the gravel at the bottom, and dragged that exact side along a flat rock. The marked side. It scraped, lifted, came back up to the mirror, tilted, checked, dropped down, and scraped again. Same spot. Same rock. The white blot.

Neither of them said anything for a while. The filter hummed. The other fish hung in the water like they were still waiting for the bus.

"It can see itself," Soren said finally. His voice came out smaller than he meant. "It knows the fish in the mirror is it. It knows where its own body is even when it can't feel the spot."

"Everybody said only big animals could do that," Maya said. "Apes. Elephants. Dolphins. The clever ones." She put her finger on the glass, near the wrasse, not touching it, just marking the place. "They kept a line. On this side, animals that know they're somebody. On that side, animals that don't. And the line keeps moving."

"Down," said Soren. "It keeps moving down. To smaller and smaller things." He pulled his notebook out of his back pocket and opened it on his knee. His hand was not quite steady. He wrote the date, and the word wrasse, and then he stopped, because the next thing he wanted to write was a question and he didn't have words small enough for it yet.

"So how far down does it go," Maya said. It wasn't really to him. "How many things out there know they're somebody and we just never gave them a mirror."

Soren looked back at the tank. The wrasse had come up off the rock and returned to the corner where the two panes met, to the faint doubled ghost of itself. It held its body at that careful angle again. Studying the one in the glass. The one that was also it.

Maya clipped the dentist's mirror lower this time, down by the gravel, angled up, so the fish could see its own underside, a part of itself it had surely never met.

The wrasse swam down to look.