An Ark dev said that these will be tameable in the future!

Tamable using fish baskets from aberration. They seem to flee from the baskets once placed. It is a good strategy to pen then in with fence foundations and walls, or kite them to a pen. Place your basket on the other side of the wall and catch.

Place a fish basket to tame this.

They can be tamed on Aberration by placing a fishing basket in the water, waiting about 30 seconds, and interacting with the basket when relatively close