click for previous page 3958 Bony Fishes DIODONTIDAE Porcupinefishes (burrfishes) by J.M. Leis iagnostic characters: Small to medium-sized (to 1 m) fishes. Body wide and capable of great Dinflation, covered with massive spines which may be quite long; spines with large bases or roots which are hidden under skin; long spines usually erectile and 2-rooted, short spines fixed in erect position by their 3-rooted bases. Head broad and blunt. Nasal organ usually in small tentacles located in front of large eyes. Mouth large, wide, and terminal, teeth fused to form a strong, beak-like crushing structure without a median suture dividing upper and lower jaws into left and right halves. Gill opening a relatively small, vertical slit immediately before pectoral-fin base. Dorsal and anal fins without spines, set far back on body, and like caudal fin, generally rounded; most fin rays branched; bases of fins often thick and fleshy; no pelvic fins. Lateral line inconspicuous. No normal scales. Colour: background colour light tan to brown, but grey not uncommon; usually overlain with dark brown to black spots, bars and/or blotches; green overtones and yellowish spots may also be present; undamaged spines covered with skin which continues colour pattern; belly white, often with yellow overtone; a pelagic species is deep blue dorsally, and juveniles of species with a pelagic phase may also be blue. eye large erectile or fixed large fin rays branched nasal tentacle parrot-like beak no pelvic fin inflatable belly restricted gill opening Habitat, biology, and fisheries: Most species are benthic around coral or rocky reefs, but some frequent sea grass beds and sand or mud bottoms to 150 m, and a single species plus the juveniles of others are pelagic. They feed on hard-shelled benthic invertebrates which are crushed with powerful jaws. They inflate when disturbed and present a potential predator with a large, very spiny ball. Most or all spawn pelagic eggs and pass through a pelagic juvenile phase. Juveniles are commonly preyed upon by large, pelagic predators such as tunas and billfishes. The pelagic species may school, but the others are not known to school. Not normally eaten except perhaps as fish meal, but often collected as bycatch in bottom trawls. Sometimes inflated and dried to be sold as curios. Thought to be poisonous, but some species eaten by traditional societies in the Pacific islands without ill effects. Similar families occurring in the area No other family has the following combination of characters: large spines on body; no pelvic fins; inflatable body; teeth fused into a single beak-like unit in each jaw, without median suture dividing upper and lower jaws into right and left halves. Tetradontiformes: Diodontidae 3959 2 roots Key to the species of Diodontidae occurring in the area 3 roots 1a. All body spines erectile (movable through at least 90°) and 2-rooted1/ (Fig. 1a) (except a few around gill opening or dorsal-fin base) ......(Diodon) ® 8 1b. All or most body spines of back and sides fixed in an erect position (not movable through 90°) and 3-rooted (Fig. 1b) .....................® 2 individual immoveable erectile spine spine 2a. Spines on top of head and on belly erectile ......................® 3 a) Diodon b) other genera 2b. Spines on top of head and on belly fixed in an erect position ............® 4 Fig. 1 surface view of bony spine 3a. Two to 4 spines in first row on snout point toward mouth when not erect; no small, black spots scattered more or less uniformly over head and trunk (Fig. 2) . Lophodiodon calori 3b. All erectile spines point toward tail when depressed; small, black spots scattered more or less uniformly over head and trunk (Fig. 3) . Dicotylichthys punctulatus (juvenile, 70 mm) Fig. 2 Lophodiodon calori Fig. 3 Dicotylichthys punctulatus 4a. A small spine or 2 wholly on dorsal surface of caudal peduncle; normally 10 caudal-fin rays; adults with spotted fins (Fig. 4) . Chilomycterus reticulatus 4b. No spines wholly on caudal peduncle; normally 9 caudal-fin rays; no spots on fins of adults .................................................® 5 5a. A set of 4 long spines with their bases near dorsal- and anal-fin bases and their pointed ends extending over caudal peduncle; 2 very long spines (longer than rays of pectoral fins) in pectoral-fin axil (Fig. 5) . Tragulichthys jaculiferus 5b. No especially long spines around dorsal-and anal-fin bases; spines in pectoral-fin axil not particularly long ..................................(Cyclichthys) ® 6 Fig. 4 Chilomycterus reticulatus Fig. 5 Tragulichthys jaculiferus 1/ There may be a short anterior extension of the spine shaft which resembles a short, third root (Fig. 1). All roots covered by skin. 3960 Bony Fishes 6a. Few black spots on body, those present at base of spines dorsally and dorsolaterally; dorsal, anal, and caudal fins with dusky distal margin; only 2 spines over eye; 2 spines between nostrils, 1 imme- diately adjacent to each nostril (Fig. 6) . Cyclichthys hardenbergi 6b. Black spots in clusters dorsally and laterally, or associated with spine bases laterally and ven- trally; dorsal, anal, and caudal fins Fig. 6 Cyclichthys hardenbergi either clean or with faint, parallel bands; 3 spines over eye; only 1 spine between nostrils, located medially ...................® 7 7a. Spines few, 4 dorsally between pectoral-fin bases, 8 or 9 anterior to dorsal-fin base; a short, movable spine near corner of mouth; all spines on top of head with 3 bases; black spots in clusters dorsally and dorsolaterally (Fig. 7) . Cyclichthys orbicularis 7b. Spines more numerous, 5 or 6 dorsally between pectoral-fin bases, 11 or 12 anterior to dorsal-fin base; no movable spines; some spines on top of head with 4 bases; black spots at base of spines laterally and ventrally (Fig. 8) . Cyclichthys spilostylus Fig. 7 Cyclichthys orbicularis Fig. 8 Cyclichthys spilostylus 8a. None of spines wholly on caudal peduncle (Fig. 9a); body with several large, dark dorsal blotches; no small, dark spots on fins ................................® 9 8b. One or more small spines wholly on dorsal surface of caudal peduncle (Fig. 9b); body without large dorsal blotches; all fins (except sometimes anal fin) heavily spotted ........® 10 1 or more spines wholly no spines wholly on on caudal peduncle caudal peduncle anterior end of caudal peduncle a) Diodon holocanthus b) Diodon eydouxii Fig. 9 posterior part of body (lateral view) Tetradontiformes: Diodontidae 3961 9a. Frontal spines obviously much shorter than spines immediately behind pectoral fins; small downward-pointing spine below anterior margin of eye; 17 to 22 spines from lower jaw to anus; large dorsal blotches with distinct pale border; blotch below eye not continuing over top of head (Fig. 10) . Diodon liturosus 9b. Frontal spines slightly shorter to much longer than spines immediately behind pectoral- fin base; no small downward-pointing spine below anterior margin of eye; 12 to 15 spines from lower jaw to anus; dorsal blotches without distinct pale border; blotch below eye continues over interorbital (Fig. 11) . Diodon holocanthus frontal spines short downward- pointing Fig. 10 Diodon liturosus Fig. 11 Diodon holocanthus spine 10a. Pectoral-fin rays 19 to 22; anal-fin rays 16 to 18; dorsal and anal fins somewhat pointed in adults; somewhat streamlined, head width of adults 3.3 to 4 times in standard length; 10 to 14 spines from lower jaw to anus; a wholly pelagic species coloured dark blue dorsally (Fig. 12) . Diodon eydouxii 10b. Pectoral-fin rays 22 to 25 (rarely 21); anal-fin rays 14 to 16; dorsal and anal fins rounded in adults; somewhat robust, head width of adults 2.4 to 3.3 times in standard length; 14 to 19 spines from lower jaw to anus; juveniles (up to 20 cm) pelagic, adults demersal and coloured tan to brown (Fig. 13) . Diodon hystrix pointed Fig. 12 Diodon eydouxii Fig. 13 Diodon hystrix List of species occurring in the area Note: This family is under study and nomenclatural changes may be made, but it is unlikely additional species will be recorded in the area. The symbol 0 is given when species accounts are included. 0 Chilomycterus reticulatus (Linnaeus, 1758) 0 Cyclichthys hardenbergi (de Beaufort, 1939) 0 Cyclichthys orbicularis (Bloch, 1785) 0 Cyclichthys spilostylus (Leis and Randall, 1982) 0 Dicotylichthys punctulatus Kaup, 1855 0 Diodon eydouxii Brissout de Barneville, 1846 0 Diodon holocanthus Linnaeus, 1758 0 Diodon hystrix Linnaeus, 1758 0 Diodon liturosus Shaw, 1804 0 Lophodiodon calori (Bianconi, 1854) 0 Tragulichthys jaculiferus (Cuvier, 1818) References Leis, J.M. 1978. Systematics and zoogeography of the porcupine-fishes (Diodon, Diodontidae, Tetraodontiformes) with comments on egg and larval development. U.S. Fish. Bull., 76(3):535-567. Leis, J.M. 1986. Family Diodontidae. In Smith’s sea fishes, edited by M.M. Smith and P.C. Heemstra. Johannesburg, Macmillan South Africa, pp. 903-907. 3962 Bony Fishes Chilomycterus reticulatus (Linnaeus, 1758) En - Spotfin burrfish. Maximum standard length about 75 cm. Young pelagic, to about 20 cm standard length, adults on reefs and soft bottoms to depths of 100 m, may occur deeper in tropics. Solitary, feeds on hard-shelled invertebrates. Not usually marketed. Circumtropical, but patchy occurrence. Not reported from vast portions of the area, and it is not clear if this apparent absence is real. * * * * * * * juveniles captured pelagically Cyclichthys hardenbergi (de Beaufort, 1939) En - Hardenberg’s burrfish. Maximum standard length about 25 cm. Found over soft bottoms to depths of 100 m, usually trawled. Presumably solitary and feeds on hard-shelled invertebrates. Not usually marketed. Tropical Australia west of Cape York and southern New Guinea. Cyclichthys orbicularis (Bloch, 1785) En - Birdbeak burrfish; Fr - Porc-épic bécard; Sp - Puercoespín pajarito. Maximum standard length about 15 cm. Found from surface to 150 m, usually over soft bottoms, but occasionally on reefs.