LEIS: TETRAODONTOIDEI 



449 



Fig. 242. Tetraodontoid yolk-sac larvae. All specimens are enclosed 

 in a more or less well-developed vesicular dermal sac. The vesicles are 

 omitted in the drawmgs. From top to bottom: Lagocephalus tunaris 

 (Tetraodontidae) 1.7 mm (1.9 mm TL) (after Fujita, 1966); Fugii par- 

 dalis (Tetraodontidae) 2.6 mm (2.84 mm TL) (after Uchida et al., 1 958); 

 Diodon (hystnx^) (Diodontidae) 2.6 mm (after Leis, 1978); and Ran- 

 -aiiia laevis (Molidae) 1.8 mm (after Lets, 1977). 



conditions [freshwater species commonly have larger eggs than 

 their marine confamiliais (Roberts, pers. comm.)]. The chorion 

 is adhesive. Parental care of eggs is known, but not universal. 

 Development of larvae at hatching varies with species: jaws 

 totally unformed to partially formed; the eye ranges from un- 

 pigmented to completely pigmented; the pectoral bud may be 

 present or absent; a moderately developed vesicular dermal sac 

 encloses head and trunk; much yolk remains; and pigment ranges 

 from moderate to heavy (Fig. 242). If the often huge yolk sac 

 is ignored, larvae are initially cylindrical, but become progres- 

 sively deeper and wider-bodied with growth (Fig. 243). Larvae 



Fig. 243. Tetraodontoid larvae. From top to bottom: Unidentified 

 tctraodontid larva (possibly Canlhigaslcr), 3.6 mm, from the Great 

 Barner Reef. Note small spines in skin; Tragnlichlhys jacitliferus (Dio- 

 dontidae), 4.2 mm. from the Great Barrier Reef (small circles in the 

 dermal sac represent incipient spines and arc ossified); and Ranzania 

 lac'vis (Molidae), 3.9 mm (after Leis, 1977). 



remain deeper than broad until they acquire the ability to inflate. 

 Until mid-preflexion stage the body remains relatively fusiform 

 with a well-developed tail (relative to other tetraodontoids and 

 ostraciids). The moderately-developed vesicular sac often dis- 

 appears during the pretlexion stage, but may be retained in some 

 species until after flexion. This sac does not correspond to the 

 inflatable belly found in this family. The gill opening closes to 

 a pore shortly after the yolk is absorbed, but the membranes 

 are thin and transparent and thus easily missed. Sequence of fin 



