Some 85 koi were stolen from a decorative pond outside a Yucaipa restaurant, authorities said, as two masked men were caught on a surveillance video hauling buckets of them away.
Investigators later serving a search warrant on a home said they noticed a large water tank.
But by then, only five koi were recovered.
Photos shared by Oak House restaurant on social media show the pair with their faces covered and the buckets in hand during the early morning hours of June 21.
While the motive remains under investigation, Koi are highly valued for their size and vibrant coloration, and can sell for anywhere from $50 to $1,500 each, depending on their lineage, San Bernardino Sheriff’s Department spokeswoman Gloria Orejel said.
Deputies used surveillance footage and vehicle tracking to locate one of the suspects. When investigators served a search warrant at his residence, they said, they discovered a large water tank believed to have held the stolen fish.
One suspect is now under arrest, and authorities are still searching for the second, the sheriff’s department said.
As of Thursday afternoon, the whereabouts of the remaining 80 fish were also unknown.