About Diodon liturosus Shaw, 1804
Diodon liturosus Shaw, 1804, commonly called the Black-blotched porcupinefish, is a medium-sized fish. It reaches a maximum length of 65 cm (26 in), while the average size most commonly observed is 45 cm (18 in). It has an elongated body, a spherical head with large round protruding eyes, and a large mouth that is rarely closed. It has large pectoral fins, no pelvic fins, and anal and dorsal fins positioned close to the caudal peduncle. The anal and dorsal fins move simultaneously when the fish swims. All fins are a uniform white or yellowish tint with no spotting. Its skin is smooth and firm, with scales modified into spines that point toward the back. Its body base color ranges from light brown to sandy yellow, with dark blotches outlined by white lines, and a pale ventral surface. It can be confused with the long-spine porcupinefish, Diodon holocanthus, but the Black-blotched porcupinefish has much shorter spines and lacks a dark streak running between its eyes. When threatened, the porcupinefish can inflate itself by swallowing water. This increases its body volume to deter predators, and it can also raise its spines for defense. The species concentrates the powerful neurotoxin tetrodotoxin in parts of its body including the liver, skin, gonads, and viscera. This toxin acts as an additional defense to discourage potential predators. The Black-blotched porcupinefish lives in tropical and subtropical waters. It occurs in the Indo-Pacific region from the eastern coasts of Africa to Japan, the Society Islands, and Western Australia, and also in the southeastern Atlantic Ocean off the coast of South Africa. Adult individuals prefer lagoons, top reefs, and seaward coral or rocky reefs at depths between 1 and 90 m, though they are most often found between 15 and 30 m depth.
