dorsal surfaces. No melanophores are present 

 on the postanal myomeres or on the dermal 

 sac. 



Identification of Eggs: The combination of size 

 ( >1.5 mm) and numerous oil droplets serves to 

 distinguish the eggs of D. holocanthus from 

 those of all other pelagic eggs except those of 

 other tetraodontiform species. The eggs of the 

 molid Ramania laevis have been described by 

 Leis ( 1977). Ramania laevis eggs may be distin- 

 guished from D. holocanthus eggs by the 

 former's smaller size (1.4-1.65 mm) and by the 

 extensive pigment which develops on the ven- 

 tral surface of the yolk sac of R. laevis in the 

 middle stage. 



Hawaiian ostraciid eggs (Ostracion and Lac- 

 toria) may be distinguished by their slightly 

 oblong shape, fewer oil droplets ( <10), but most 

 reliably by a patch of bumps on the chorion 

 surrounding the micropyle. This "rough patch" 

 is easilv overlooked. 



FISHERY BULLETIN; VOL. 76. NO, 3 



Diocion hystrix eggs are the only other Diodon 

 eggs known ( see section on D. hystnx). They can 

 be distinguished from those of D. holocanthus by 

 their larger size ( >1.9 mm), greater number of 

 oil droplets ( >30), and the orange (rather than 

 red) pigment. 



Larval Development: Fifteen reared and 12 

 field-collected larvae in good enough condition 

 for descriptive purposes were available. Mor- 

 phometric data are summarized in Table 4. 



The newly hatched larva has well-developed, 

 apparently functional eyes, jaws, and gas blad- 

 der (Figure 22). The pectoral fins are quite 

 large, although no rays are formed. The larvae 

 are 1.9-2.1 mm SL at hatching and the body is 

 rotund. Development in reared larvae is slow. 

 Dorsal and anal fin anlagen form by day 10 (2.4 

 mm, Figure 22); the olfactory pit also forms by 

 this time and the eyes have become proportion- 

 ally larger. The oldest reared larva available 

 was 16 days old, but it was smaller than the 



Table 4. — Morphometric and meristic data for larval and juvenile Diodon holocanthus 

 (measurements in mm). ? indicates individuals of unknown age, from plankton samples; 

 X indicates damaged. 



'Fish in emaciated condition. 



560 



