Updated

Poachers in Mexico have long smuggled the swim bladders of the totoaba, an endangered fish prized in China.

But federal police said Thursday they've now found a shipment of 104 frozen totoaba fish fillets at the Tijuana airport. That suggests smugglers are seeking to take advantage of the whole fish.

Fishing for totoaba is prohibited in Mexico's Gulf of California, but the high prices paid for dried swim bladders have made that hard to enforce. Poachers in the past simply discarded the fish carcasses after extracting the bladders.

Nets set for totoaba frequently catch the highly endangered vaquita marina, the world's smallest porpoise. Fewer than 30 vaquitas are thought to remain.