ABOUSSOUAN AND LEIS: BALISTOIDEI 



455 



Table 117. 



Characters That Differ Between the Two Larval 

 monacanthid morphs. 



Fig. 248. Late to mid preflexion larvae of two balistoid families. 

 Small ticks indicate position of dermal spinules. From top to bottom: 

 Canlhidenms sufflamen (Balistidae), 3.5 mm, from Puerto Rico, note 

 small pelvic bud and prcopercularclustcr of spinules; unidentified Morph 

 A monacanthid, 3.6 mm, from the Great Bamer Reef, note pigmented 

 filament at terminus of pel vie bone and preopercular cluster of spinules; 

 Pseudatulans nasicorms (Morph B monacanthid), 4.3 mm, from the 

 Great Barrier Reef, note pigmented fleshy tendrils laterally on tail and 

 preopercular cluster of spinules; unidentified Morph C monacanthid, 

 3.0 mm from the Great Bamer Reef Dermal spinules in this species 

 are longer than in the other illustrated species. Dorsal spine is just 

 beginning to form (not yet ossified). 



appear in the form of a small cluster of relatively long spinules 

 on the preoperculum (larval specialization). This cluster appears 

 within a few days of hatching and persists until just prior to 

 flexion. Shortly before the cluster disappears, dermal spinules 

 appear in three areas: laterally on the cheek ventral to the cluster; 

 over the otic vesicle; and laterally on the gut from below the 

 pectoral base to near the anus. These unspecialized spinules 

 rapidly spread to cover the body by mid-flexion. They do not 

 transform into the specialized scales of the adults until well into 

 the pelagic juvenile stage. A pigmented filament (larval spe- 

 cialization) often develops at the terminus of the pelvic bones 

 (see discussion of such structures under Monacanthidae). Pig- 

 ment is heavy on the brain and gut, and preflexion larvae have 

 a series of melanophores on the ventral midline of the tail. 

 Blotches or bands may form on the tail. The spiny dorsal fin is 

 heavily pigmented and this pigment spreads laterally over the 

 trunk. 



Berry and Baldwin (1966) describe juvenile development of 

 several balistid species. 



Monacanthidae 



Monacanthid eggs are demersal (we tentatively conclude that 

 pelagic eggs were wrongly attributed to Parika scaher—see Table 

 1 16), adhesive, small, have several oil droplets, and hatch in 

 about 2 days. Eggs are attached to vegetation, and there is no 

 record of parental care. Development at hatching is not ad- 

 vanced: jaws are absent or only partially formed, the eye is 

 unpigmented, and much yolk remains (Fig. 246). Newly-hatched 

 larv ae are cylindrical and somewhat compressed. Morphological 

 and developmental diversity among monacanthid larvae is high. 



