VIDEO: Whale shark surprises fishing crew off South Texas Coast

SAN ANTONIO – A fishing trip in Port Mansfield led to a surprise by the largest fish species in the world swimming in the Gulf of Mexico.

Dr. Tim Bonner, a biology professor at Texas State University, told KRGV-TV he was fishing off the jetties Tuesday when he and his friends spotted a large shadow in the water.

A video shared by Bonner on YouTube shows the whale shark swimming underneath their boat towards a bait ball – an event when small fish move in a tight formation.

"(The whale shark is) probably sticking around because he was getting some meals," Bonner told KRGV.

While Tuesday's spectacle was unexpected, Bonner told KRGV that spotting whale sharks in the Gulf of Mexico is not unusual and they have been seen in the past.

Bonner said he suspects the whale shark sighting was due to warmer water temperatures in the Gulf, adding they are often seen off the coast of the Yucatan Peninsula roaming the tropics.

To view the incredible moment, click on the video above.