DIODONTIDAE Porcupinefishes By Keiichi Matsuura Diodon hystrix Diodon liturosus Small to medium sized fishes, to 1 m in length. Body covered with strong spines which may be very long; the spines have large bases under the skin; long spines erectile. Gill opening a relatively small, vertical slit just before pectoral-fin base. Jaws modified to form a beak of two heavy, powerful teeth, one each on upper and lower jaws. Dorsal and anal fins without spines; pelvic fin absent. Typical scales absent. Color: background color light tan to brown, usually overlain with dark brown to black spots. Similar families occurring in the area. Tetraodontidae: no strong elongate spines cover head and body; two tooth plates in each of the upper and lower jaws (single tooth plate in each jaw in Diodontidae). Remarks. Most species benthic around coral or rocky reefs, but some seen in sea grass beds and sand or muddy bottoms to a depth of 150 m; juveniles pelagic. Feed on hardshelled benthic invertebrates.