Porcupinefishes or balloonfishes, are any of the various species of the genus ''Diodon'', the

type genus In biological taxonomy, the type genus (''genus typica'') is the genus which defines a biological family and the root of the family name. Zoological nomenclature According to the International Code of Zoological Nomenclature, "The name-bearin ...

of Diodontidae.

Distinguishing features

Fish of the genus ''Diodon'' have: * two-rooted, movable spines (which are derived from modified scales) distributed over their bodies. * beak-like jaws, used to crush their hard-shelled

prey Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not ki ...

(

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s and

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

s). They differ from the

swelltoad ''Cyclicthys'' is a genus of fish in the porcupinefish family, Diodontidae. Species in the genus are often known as swelltoads. Distinguishing features Fish of the genus ''Cyclicthys'' have three-rooted, rigid spines (actually modified scales) d ...

s and burrfishes (genera '' Cyclichthys'' and '' Chilomycterus'', respectively), which, in contrast, have fixed, rigid spines.

Defense mechanisms

* Like true pufferfishes of the related family Tetraodontidae, porcupinefishes can inflate themselves. Once inflated, a porcupinefish's erected spines stand perpendicular to the skin, whereupon they then pose a major difficulty to their predators: a large porcupinefish that is fully inflated can choke a

shark Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...

to death. According to Charles Darwin in ''The Voyage Of the Beagle'' (1845), Darwin was told by a Doctor Allen of Forres, UK that the Diodon actually had been found "floating alive and distended, in the stomach of the shark" and had been known to chew its way out of shark bodies after being swallowed, causing the death of its attacker. * They may be poisonous, through the accumulation of

tetrodotoxin Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an Order (biology), order that includes Tetraodontidae, pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Alt ...

ciguatera Ciguatera fish poisoning (CFP), also known as ciguatera, is a foodborne illness caused by eating tropical reef fish contaminated with ciguatoxins. Such individual fish are said to be ciguatoxic. Symptoms may include diarrhea, vomiting, numbness ...

.Lieske, E. & Myers, R.F. (2004): ''Coral reef guide; Red Sea'' London, HarperCollins

Species

Extant species

There are currently five recognized extant species in this genus:

Fossil species

Fossils of ''Diodon'' are known from

Tertiary Tertiary (from Latin, meaning 'third' or 'of the third degree/order..') may refer to: * Tertiary period, an obsolete geologic period spanning from 66 to 2.6 million years ago * Tertiary (chemistry), a term describing bonding patterns in organic ch ...

-aged marine strata. These species are similar to modern species. Fossil species include: * †'' Diodon scillae''

Agassiz Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history. Spending his early life in Switzerland, he recei ...

, 1843 -

Late Miocene The Late Miocene (also known as Upper Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages. The Tortonian and Messinian stages comprise the Late Miocene sub-epoch, which lasted from 11.63 Ma (million ye ...

of Cuba * †'' Diodon serratus'' Aguilera ''et al'', 2017 -

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene epoch (geology), epoch made up of two Stage (stratigraphy), stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0. ...

of Venezuela * †'' Diodon sigma'' Martin, 1883 - Miocene of

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

, Indonesia

References

Diodontidae Marine fish genera Taxa named by Carl Linnaeus {{Tetraodontiformes-stub