LEIS: SYSTEMATICS AND ZOOGEOGRAPHY OF THK PORCHPINEFISHES 



with broad lateral bases form the anterior border 

 of the gill opening. No spines on the snout. 



No barbels or fleshy tentacles. 



Dorsally the ground color is light grey to brown 

 grading to white ventrally. Dorsal and lateral sur- 

 faces marked with dark ovoid spots ( <eye diame- 

 ter in length) most of which are associated with 

 the spine axils, particularly on the sides posterior 

 to the pectoral fin. Caudal peduncle usually mot- 

 tled dorsally. Round spots (often diffuse) present 

 on dorsal, pectoral, and caudal fins (caudal spots 

 first seen on 100-mm fish, other fin spots begin to 

 form between 30 and 100 mm). The pectoral spot- 

 ting is limited to two vertical rows of four to six 

 spots each. The anal fin is often dusky but never 

 spotted. A dark gular band extends from the eye 

 downward and forward, generally paralleling the 

 ventral outline of the head. Usually a branch of 

 this band extends dorsally between the eye and 

 gill opening and is often discontinuous with the 

 gular band. Specimens <100 mm usually have 

 four opposed spots on the iris. 



In life the dorsal ground color is medium to dark 

 blue while the dorsal and lateral spots and gular 

 band are dark blue to black. The ventral surfaces 

 are silvery- white and the fins greyish (from a color 

 transparency provided by R. Rosenblatt, SIO). 



The largest specimen examined is 252 mm, but 

 the next largest is only 177 mm, apparently a 

 fairly small species. Twelve specimens ( 125-153 

 mm) were sexed although none were ripe: 7 males 

 and 5 females. 



Eggs, larvae, and pelagic juvenile stages. — No in- 

 formation is available on eggs or larvae. The 

 smallest specimen available is 4.5 mm and is in 

 very poor condition. The fish is almost completely 

 round (inflated?); the spines are short (ca. 0.25 

 mm) and of uniform length over most of the body. 

 By 13 mm the frontal and pectoral axil spines are 

 ca. 2.5 mm — noticeably longer than the rest of the 

 spines. In the smallest specimen the spines are all 

 erect and the bases resemble small tripods; they 

 may well be fixed at this stage. However, by 8.5 

 mm the spines are erectile and the fish is definitely 

 capable of inflation. In the 4.5-mm specimen the 

 fin rays are fully formed, as are the nostrils. 



The fins remain unpigmented until at least 30 

 mm except for a small dusky area at the pectoral 

 fin base which forms by 13 mm. In both dorsal and 

 caudal fins, spots gradually spread over the fin 

 from the base. The first row of pectoral fin spots 

 form by 100 mm and the second at about 150 mm. 



The smallest fish are uniformly dark to medium 

 brown dorsally with a light area at the base of each 

 spine due to the unpigmented spine sheath. Later- 

 ally, distinct black spots (0.25-0.50 mm in diame- 

 ter) are found. These continue across the white 

 ventral surface. By 8.5 mm the white area at the 

 spine bases has disappeared and spots similar to 

 those on the ventral surface have developed on the 

 dorsal surfaces. The spots are now ca. 1 mm in 

 diameter. The ventral spotting is less conspicuous 

 due to the loss of individual spots by 13 mm, and by 

 20 mm the belly is white and devoid of spots. The 

 dorsal and lateral spots persist and become as- 

 sociated with the spine bases by 100 mm. 



Syntypes. —MNHN 2153, two specimens (101 and 

 108 mm) taken (apparently speared) in the Pacific 

 between Guayaquil and Hawaii. 



Distribution . — Diodon eydouxii is a pelagic, 

 oceanic species which is found circumtropically 

 (Figure 8) and seems particularly abundant in the 

 eastern Pacific, but this may be an artifact of col- 

 lecting effort. 



Remarks. — In Brissout de Barneville's ( 1946:142) 

 description, the total mention o^ Diodon eydouxii 

 is as follows: "Mentionnons encore le Diodon 

 Eydouxii, Souleyet (Bibron, Coll. Mus. Paris, et 

 Monographie inedite des Diodoniens) remarqu- 

 able par ses nageoires dorsale et anale subfal- 

 ciformes." As noted by Brissout de Barneville, 

 Bibron in his unpublished manuscript (MNHN 

 Library MS #867) cited Souleyet as the author of 

 this species. However, Souleyet, insofar as I can 

 determine, never published anything regarding 

 this species. In fact, Bibron's (MS, p. 96) citation 

 refers to the "Voyage de la Bonite. Zool. p . . . . ," 

 i.e., he gave no page number, as if in anticipation 

 of publication by Souleyet. There is no mention of 

 D. eydouxii in "Voyage de la Bonite" (Eydoux and 

 Souleyet 1841). Because Brissout de Barneville 

 was the first person to use this name in a published 

 work and because he included descriptive 

 information — albeit limited, Diodon eydouxii 

 should be attributed to him. 



Kaup's (1855) description of Z). melanopsis is 

 inadequate, but one of his syntypes (BMNH 

 1852.3.2.7) is extant. Information provided by 

 A. C. Wheeler (pers. commun., BMNH, 29 October 

 1975) is sufficient to place D. melanopsis in the 

 synonomy of D. eydouxii. Giinther ( 1870) incor- 

 rectly placed D. melanopsis in synonomy with D. 



543 



