When the gulf totoabas mate, they always make a loud noise without shame. Every year, this species gathers en masse in the Gulf of Mexico to lay its eggs. Like crickets, cicadas, and frogs, male totoabas call out to love and attract females. A November 2017 study published in Biology Letters found that the call of a bay totoaba is the loudest fish ever recorded by humans, even less than a whale' call, so the call of a totoaba can be considered one of the largest natural sounds in the ocean.
"At first, we thought the instrument was broken," said Brade Erisman, a fisheries ecologist at the University of Texas at Austin, a collaborator in the study.
Elliesman and his colleagues came to the junction of the Colorado River Delta and the Cortez Sea. The 8-meter-high tide in the delta can wash the eggs into the sea, which is why the bay totoaba chose this place as the only spawning place.
The researchers used echo detectors (sonar devices) and underwater listeners (underwater microphones) to measure the sound emitted by the totoaba. From the analysis, they estimated that about 1.5 million totoabas had gathered in a 27,000-meter-long channel during a peak spawning day. The researchers say the total amount of totoaba is likely to be much more than that.
There are more than 1,000 species of fish that make a call, but researchers believe that totoaba is definitely a unique totoaba that makes a sound when mating, reaching 177 decibels, which is louder than the sound felt when standing next to the stage at a rock concert. The noise is so loud that if other sea creatures happen to witness it, their hearing is likely to be damaged. "The study was very rigorous and convincing," commented Stephen Simpson, a marine biologist and fish ecologist at the University of Exes in the United Kingdom who was not involved in the study.
Bay totoabas gather year after year to spawn at the mouth of a river and are easily overfished, which is dangerous. "This behavior of totoabas is crazy, they come together to spawn, it's actually very dangerous, humans can easily catch them all," Errisman said. In the era of gillnets and trawls, the evolution of mass spawning habits could only lead them into a reproductive crisis.
Article source: Global Science, 2018.5