Balloonfish, Diodon holocanthus. Photograph of an agitated Balloonfish taken in vivo in the waters off Todos Santos, Baja California Sur, March 2014. Photograph courtesy of Melissa Ward, Davis, California.

Balloonfish, Diodon holocanthus. Fish caught from shore at Los Barriles, Baja California Sur, January 2018. Length: 18 (7.1 inches). Catch courtesy of Kyle Rousseau, Maple Ridge, British Columbia, Canada. Photograph courtesy of Brad Murakami, Surrey, British Columbia, Canada.

Balloonfish, Diodon holocanthus. Fish caught from coastal waters off Mazatlán, Sinaloa, October 2021. Length: 23 cm (9.1 inches). Catch, photograph and identification courtesy of Bart, The Netherlands  (worldangler.eu).

Balloonfish, Diodon holocanthus. Three different fish caught from shore at Km 21, Cabo Real, Baja California Sur, June 2008. Length: all a consistent 25 cm (10 inches). A fish with personality that provides unique photographic opportunities.

Balloonfish, Diodon holocanthus. Fish caught off Point Palmilla, Baja California Sur, November 2017. Length: 40 cm (16 inches). Catch courtesy of Mauricio Correa, Los Cabos, Baja California Sur.

Balloonfish, Diodon holocanthus. Underwater photographs taken in Zihuantanejo Bay, Guerrero, March 2018. Photographs courtesy of Maude Jette, Dive Zihuantanejo,   www.Divezihuantanejo.com.

Balloonfish, Diodon holocanthus. Underwater photograph taken in Zihuantanejo Bay, Guerrero, March 2018. Photograph courtesy of Ron Woheau, Zihuantanejo.

Balloonfish, Diodon holocanthus. Underwater photograph taken in coastal waters off Puerto Vallarta, Jalisco, July 2023. Photograph courtesy of Kevin Erwin, Seattle, Washington.

The Balloonfish, Diodon holocanthus, is a member of the Porcupinefish or Diodontidae Family, that is also known as the Longspined Porcupinefish and in Mexico as pez erizo mapache or simply botete. Globally there are seven members of the genus Diodon, of which four are found in Mexican waters, one in the Atlantic, one in the Pacific and two in both the Atlantic and the Pacific Oceans.

The Balloonfish has a robust, oval, and inflatable body, with a wide blunt head, a pair of small barbels on the chin, disproportionately large eyes, strong parrot-like teeth on both jaws, and a large mouth. Dorsally they are light olive to pale brown in color with their shading changing to white ventrally. Their upper head and body are covered with small black spots. The black spots on their belly become very prominent when the fish are inflated. There are brown bars running from above to below their eyes, across their upper back, and a shorter bar across the middle of their back. They have a large oval brown blotch above each pectoral fin and another around the dorsal fin base. Their fins are without spots, which is a key to identification. Their body and head are covered with numerous long, erectile, slender, and round spines; a row of 12 to 16 erectile spines run from the top of their snout to their dorsal fin. Their caudal fin base is spineless.

The Balloonfish is found inshore near the bottom in and around protected areas that offer shelter such as caves, shipwrecks, reefs, ledges and within coral and rocky reefs and open sand rubble bottoms at depths up to 100 m (330 feet). The Balloonfish reach a maximum of 50 cm (19.7 inches) in length but are common at lengths of 25 cm (10 inches). As of January 1, 2024, the International Game Fish Association world record stood at 0.95 kg (2 lbs 1 oz) with the fish caught in coastal waters off Japan in July 2005. Balloonfish are nocturnal predators consuming crabs, snails, and urchins and are generally found hiding in crevices during the day. Juveniles are pelagic with an open oceanic lifestyle until reaching 15 cm (6 inches) in length, after which they move to coastal environments and become benthic. They are preyed upon by large carnivorous fish including dorados, sharks, and wahoos. They are capable of expanding their body size by taking in water and inflating, which they use as an effective defense mechanism.

The Balloonfish is a circumglobal warm water species found in all tropical waters of the globe. In Mexican waters they are residents of both the Atlantic and the Pacific Oceans. In the Atlantic they are found throughout the Gulf of Mexico and the east coast of the Yucatán Peninsula in the Caribbean. In the Pacific Ocean they are found in all waters except that they are absent from the extreme northwest section of the Sea of Cortez.

The Balloonfish is straightforward to identify noting that the similarly-appearing Porcupinefish, Diodon hystrix, the Pelagic Porcupinefish, Diodon eydouxii, and the Spotfin Burrfish, Chilomycterus reticulatus, all of these have spotted fins.

From a conservation perspective the Balloonfish is currently considered to be of Least Concern with stable, widely distributed populations. The Balloonfish is fairly common and readily accessible via surf fishing at certain times of the year in the greater Los Cabos area. They are considered a “catch and release” as they might contain the potent neurotoxin tetrodotoxin, thus human consumption is not recommended. They are used on a very limited basis to make curios and sold in local Mexican markets as house decorative items; they are fairly common in public aquariums; and, they are used on a limited basis in Asian medicinal practices.