FISHERY BULLETIN: VOL. 76, NO. 3 



Table 3. — Morphometric and meristic data for larval and juvenile Diodon hystrix (mea- 

 surements in mm). ? indicates individuals of unknown age caught in plankton samples; 

 X indicates damaged. 



Figure 12.— Pelagic juvenile oi Diodon hystrix, 26 mm SL, western Atlantic (NMFS M Oregon II 72-39-36). 



Diodon occur in the Red Sea where Sanzo obtained 

 his specimens; only D. hy.strix is reported to occur 

 there (e.g., Clark and Gohar 1953). 



Metamorphosis to the spiny juvenile stage oc- 

 curs before 5 mm SL. Juveniles of D. hystrix are 

 similar in shape, development, and pigmentation 

 to D. holocanthus except that the spines of the 

 former are shorter and its snout is more heavily 

 pigmented (Figure 12). Diodon hystrix juveniles 

 remain pelagic for an unknown time, but the 

 largest pelagic individual seen was 180 mm while 

 the smallest individual taken inshore was 191 

 mm. 



Holotype. — No holotype or type-series is known to 

 exist. Linnaeus based his description on that of 

 Artedi (1738). 



Distribution. — Diodon hystrix is found circum- 

 tropically (Figure 8) and often in temperate areas, 

 especially in the western boundary currents. This 

 species apparently is the only member of the genus 

 in the Mediterranean (Torchio 1963). 



Remarks. — Linnaeus provided very little diagnos- 

 tic data in his brief description, the useful infor- 

 mation consisting of a mention of long spines, 

 chiefly on the sides. This could apply to D. hystrix, 

 as described above, D. liturosus, or D. eydouxii. 

 Bloch (1785) was the first to use recognizably the 

 name hystrix. His illustration of "D. hystrix" is 

 clearly of the species here considered as D. hystrix. 

 Several authors have incorrectly applied the 

 name Diodon atinga Linnaeus to this species (see 

 synonomy), but it is clear from the original de- 



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