The totoaba (Totoaba macdonaldi) is a large fish found in the Gulf of California, in Mexico and the United States. They can grow to 100 kilograms (220 pounds) and 2 meters (6.5 feet), and can live for 20-25 years.
Totoaba have small eyes and limited vision, and the top of their dorsal and anal fins lack scales; instead they have a scaly-like sheath at the base. They are golden, with some totoaba having a blueish tone. Juvenile totoaba have dark spots on their back.
The totoaba takes 4-5 years (and sometimes up to 7) to become sexually mature. This makes them vulnerable to climate changes because they reproduce more slowly, and therefore adapt more slowly. The totoaba does not show sexual dimorphism except when the female is pregnant.
Adult totoaba fish migrate to the Colorado River Delta in the beginning of March. Females lay their eggs, and the adult totoaba head back to the Gulf of California around June. The young totoaba will stay near the coast for 2-3 years. When they are fully mature they will return every year to their birthplace to lay eggs.
Totoaba eat small fish, shrimp, algae, and other plants.
A vaquita swiming with totoaba. Image courtesy of Our Marine Species.
The totoaba is listed as critically endangered. The main reasons for this are bycatch, illegal fishing, and habitat changes.
Bycatch is when fish or other marine mammals are accidentally caught in nets meant for other animals. This happens often to the totoaba when they are caught in shrimp nets. Other animals such as the vaquita, as well as turtles, dolphins, other fish, and rays, also get caught in nets meant for the totoaba.
The totoaba’s swim bladder (used to control a fish’s buoyancy) is very valuable and is sold for a lot of money to many countries, namely China. The totoaba’s swim bladders are particularly prized because of their size, color and thickness. This is because swim bladders are used as medicine. Sometimes, totoaba are caught, their swim bladders are taken, and then they are thrown overboard, flooding beaches with dead fish. Totoaba swim bladders often are sold for over $20,000. Since 1975, Mexico has had a total ban on fishing totoaba but illegal fishing continues. The fishing industry for totoaba swim bladders has increased a lot since its beginnings in the 1920-40s. Resultantly, the totoaba’s population has decreased by about 95%.
Some people believe that the creations of the Hoover dam(1935) and Glen Canyon dam(1963) negatively impacted the totoaba’s habitat by reducing water flow, resulting in young totoaba having lower growth rates. However, since these dams were constructed a while ago, it seems as though the totaba has adapted to the new changes because of their ability to withstand high levels of salt content.
In addition to its ban on totoaba fishing, Mexico has implemented a program intended to conserve the totoaba and the closely entwined vaquita (a porpoise).
Fisheries, NOAA. “Totoaba.” NOAA, www.fisheries.noaa.gov/species/totoaba.
“Totoaba Fish: Characteristics, Habitat, Threats and More....” Discovering All Marine Species, 3 Nov. 2019, ourmarinespecies.com/c-fishes/totoaba-fish/.
Totoaba, Bren School of Environmental Science and Management, totoabaproject.weebly.com/.