Spotfin Burrfish, Chilomycterus reticulatus

Spotfin Burrfish, Chilomycterus reticulatus. Fish caught from coastal waters off Fort Lauderdale, Florida, December 2013. Length: 38 cm (15 inches). Catch, photograph and identification courtesy of Eli (obsessiveangling.wordpress.com).

Spotfin Burrfish, Chilomycterus reticulatus. Fish caught coastal waters north off Puerto Los Cabos, Baja California Sur, April 2007. Length: 77 cm (2 feet 6 inches). At the time of the catch this fish inflated into a symmetrical ball approximately the size of its length making it simply ginormous.

Spotfin Burrfish, Chilomycterus reticulatus. Photograph of a dried out beach collection illustrating the unique subdermal triangularly shaped spine network.

Spotfin Burrfish, Chilomycterus reticulatus. Two photographs of a fish collected off the beach in the Santa Rosalia area of Baja California Sur, November 2014. Photograph courtesy of Vikki Kaufmann.

Spotfin Burrfish, Chilomycterus reticulatus. Underwater photograph courtesy of Bob Hillis, Ivins, Utah.

Spotfin Burrfish, Chilomycterus reticulatus. Fish caught from coastal waters off Point Palmilla, Baja California Sur, May 2016. Length: 51 cm (1 feet 8 inches).  Expanded girth: 62 cm (2 feet 0 inches).

The Spotfin Burrfish, Chilomycterus reticulatus, is a member of the Porcupinefish or Diodontidae Family, that is also known as the Few-spined Porcupinefish, and in Mexico as pez erizo enano and simply botete. Globally, there are seven species in the genus Chilomycterus, of which four are found in Mexican waters, three in the Atlantic and one in the Pacific Ocean.

The Spotfin Burrfish has a rotund inflatable body with a wide blunt head with disproportionately large eyes, strong parrot-like teeth on both jaws, and a large mouth that opens in the front. Dorsally their shading is gray, ventrally it is white, while their head, body, and median fins have scattered black spots. They have 2 dark vertical lines, the first just in front of their eyes and the second just in front of their pectoral fins. Their head and body are covered with numerous short, immovable, triangular, and flattened shaped spines that are tips of plates embedded just under the skin. There is a row of 8 to 10 spines starting at the snout and ending at the dorsal fin, with 1 or 2 spines on top of their caudal fin base. Their anal fin has 11 to 14 rays and is toward the rear of the body; their caudal fin is rounded; their dorsal fin has 12 to 14 rays and is toward the rear of the body; their pectoral fins have 19 to 22 rays; and, they do not have pelvic fins.

The Spotfin Burrfish is found near the bottom in and around sheltered coral and rocky reefs and in open sand rubble bottoms at depths up to 140 m (460 feet). They are a circumglobal warm water species present in all tropical waters of the globe. They reach a maximum of 75 cm (29.5 inches) in length. As of January 1, 2023, the International Game Fish Association world record stood at 4.1 kg (9 lbs 0 oz), with the fish caught in coastal waters off Tokyo, Japan in July 2004. Adults are generally found inshore near the bottom and around areas that offer shelter such as caves, shipwrecks, reefs, and ledges. They 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 20 cm (8 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. They are reported to contain the potent neurotoxin tetrodotoxin, which is believed to help defend them against predation. The Spotfin Burrfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.

The Spotfin Burrfish is a resident of Mexican waters of both the Atlantic and the Pacific Oceans.  In the Atlantic they are found in coastal waters around the Yucatán Peninsula. In the Pacific they are found in all coastal waters with the exception that they are absent from the northern half of the Sea of Cortez. This species is exceedingly rare in the greater Los Cabos area. I have caught three by hook and line in twenty years.

The Spotfin Burrfish can be confused with the Porcupinefish, Diodon hystrix (very long spines) and the Pelagic Porcupinefish, Diodon eydouxii (dark blue with greater than 20 spines between the snout and caudal fin).

From a conservation perspective the Spotfin Burrfish is currently considered to be of Least Concern, with stable, widely distributed populations. Although large is stature they are of limited interest to most. They should be considered a “catch and release” because of the possible presence of tetrodotoxin, and are not suitable for human consumption. They are not sold commercially.