The black-blotched porcupinefish (''Diodon liturosus''), also known as shortspine porcupinefish, is a member of the family Diodontidae. It is found in the tropical and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

waters of the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

on coral and rocky reefs and in inshore waters. Other names are the blotched porcupinefish and the brown-backed porcupinefish.

Description

The Black-blotched porcupinefish is a medium-sized fish which grows up to , but the average size most likely to be observed is . Its body is elongated with a spherical head with big round protruding eyes and a large mouth that is rarely closed. The pectoral fins are large, the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s are absent, the anal and dorsal fins are close to the caudal peduncle. The latter move simultaneously during swimming. All fins are a uniform tint of white or yellowish without any spotting. The skin is smooth and firm, the

scale Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...

s are modified into spines directed towards the back. The body coloration is light brown to sandy-yellowwith dark blotches circled with a white line and pale ventral surface. The only other fish with which it might be confused is the long-spine porcupinefish, (''Diodon holocanthus'') but it has much shorter spines and it lacks a dark streak running between the eyes. In case of danger, the porcupinefish can inflate itself by swallowing water to deter the potential predator with its larger volume and it can raise its spines defensively. The porcupinefish concentrates a poison, called tetrodotoxin, in certain parts of its body such as the liver, skin,

gonad A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...

s and the viscera. Tetrodotoxin is a powerful

neurotoxin Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature ner ...

. This defensive system constitutes an additional device to dissuade the potential predators.

Distribution and habitat

The Black-blotched porcupinefish is found in the tropical and

waters of the

area from eastern coasts of Africa to Japan, the Society Islands and Western Australia, and also the southeast of the Atlantic Ocean on the coast of South Africa. Adults favour lagoons, top reefs and seaward coral or rocky reefs from one to 90 m depth, but it is usually found between 15 and 30 m.

Biology

The porcupinefish's diet is based on

Sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

s and crustaceans. This fish is solitary, except during mating periods, it has a

nocturnal activity ''Nocturnal Activity'' is a remix album by Rae & Christian, released in 2002 on the independent record label Grand Central Records. It is composed of alternative mixes of the tracks from Sleepwalking (Rae & Christian album), ''Sleepwalking'' albu ...

with a maximal activity at sunset and sunrise. During the day it normally hides in caves or under ledges.Leis, J.M., 2001. Diodontidae. Porcupine fishes (burrfishes). p. 3958-3965. In K.E. Carpenter and V. Niem (eds.) FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Vol. 6. Bony fishes part 4 (Labridae to Latimeriidae), estuarine crocodiles. FAO, Rome.

References

External links

*http://www.marinespecies.org/aphia.php?p=taxdetails&id=219970 *http://www.fishbase.org/summary/6552 *http://eol.org/pages/212629/details *http://doris.ffessm.fr/fiche2.asp?fiche_numero=2177 * {{Taxonbar, from=Q2420348 black-blotched porcupinefish Pantropical fish black-blotched porcupinefish