Description:

Dorsal spines: 0; Dorsal rays: 14-17; Anal spines: 0; Anal soft rays: 14-16.

Head broad and blunt. Mouth large, wide and terminal, the teeth fused to form a beak-like crushing structure. Body robust, wide and capable of great inflation. Body covered 
in long erectile spines, folded backwards when body not inflated. The longest spines located under the pectoral fin. Gill opening a relatively small vertical slit immediately
before the pectoral fin base. Dorsal and anal fins set far back on the body. No pelvic fins. No normal scales.

Colour. Pale olive to pale greyish-brown, shading paler ventrally.  Body and fins densely covered in small black spots. 
 

Maturity: Lm unknown. Range unknown. Max Length: 91cm TL. Commonly to 40cm TL.

Reef associated, occur in lagoon and seaward reefs (depth 2-50 m, usually 3-20 m). Adults are benthic and commonly seen in caves and holes in shallow reefs. Usually solitary,
a nocturnal fish feeding on hard-shelled invertebrates. Juveniles to about 20 cm are pelagic, larger juveniles can be found in mangrove habitats. 

This species is not protected or subject to fishery regulations. It is caught in the beach seine fishery but released as considered poisonous.

Poisonous to eat.

Bray, D.J. Diodon hystrix in Fishes of Australia, http://fishesofaustralia.net.au/home/species/476 (29/07/19).
Fischer, W. & G. Bianchi (eds), (1984).  FAO species identification sheets for fishery purposes. Western Indian Ocean; (Fishing Area 51). Prepared and printed with the 
support of the Danish International Development Agency (DANIDA). Rome, Food and Agricultural Organization of the United Nations, vols 1-6.
Froese, R. & D. Pauly. (Eds.) (2019). Fishbase. https://www.fishbase.se/summary/1022 (29/07/19).
Liu, J. et al. (2015). Diodon hystrix (errata version 2016). The IUCN Red List 2015: https://www.iucnredlist.org/species/193668/97664783 (29/07/19).

Nevill, J.E.G. (2019). Diodon hystrix, Spot-fin porcupinefish. Seychelles Seatizens. www.seatizens.sc. https://seatizens.sc/species/diodon-hystrix-linnaeus-1758/ (edited 02/07/22).