Busby and Ambrose Development of larval and juvenile Odontopyxis trispinosa and Xemeretmus latifrons 



401 



PSO-1 



APO-4 



PPO-2 

 PPO-3 



IIO-3 PPO-4 



Figure 3 



Positions and abbreviations of larval head spines and plates 

 in agonids. Based on a 17.2-mm stained larva of Odontopyxis 

 trispinosa (modified from Moser and Ahlstrom (1978), 

 Richardson and Laroche (1979), and Laroche (1986)). 



Figure 4 



Top view above eye showing superior infraorbital and frontal 

 spines of a 17.2-mm SL, cleared and stained Odontopyxis 

 trispinosa. 



dorsal and anal fins and is connected ventrally to the 

 first band by a bar. The third band extends from the 

 posterior half of the second dorsal fin to the posterior 

 half of the anal fin. The remaining four bands are 

 evenly spaced on the body between the posterior edges 

 of the second dorsal and anal fins and the caudal fin. 

 The third, fifth, and seventh bands are the widest. 

 The posteriormost band of pigmentation in postflexion 

 larvae and early juveniles is located at the hypural 

 margin and is continuous with the caudal-fin pigment. 



The entire ventral and lateral surfaces of the gut in 

 preflexion larvae are covered with pigmentation. A 

 dense row of melanophores is present along the ven- 

 tral midline from the isthmus to the end of the pre- 

 anal finfold. The ventral midline pigmentation can be 

 distinguished easily in lateral view through the 

 postflexion stage. In some specimens, a small, circular, 

 unpigmented area is present on the lateral surface of 

 the gut posterior to the pectoral-fin rays. 



Fins The base of the pectoral fin is completely cov- 

 ered with melanophores throughout development. Pig- 

 mentation is absent from the pectoral-fin blade, rays, 

 and membrane. 



Most preflexion and flexion specimens possess a 

 small group of melanophores on the anterior portion of 

 the dorsal finfold near the body margin over the g it 

 (Fig. 5A). This patch migrates posteriorly with dev< i 

 opment and becomes the pigmentation seen on the 

 first dorsal fin in postflexion larvae and juveniles 

 (Fig. 5, C and D). A larger patch of melanophores is 

 present at approximately midbody which usually ex- 

 tends to the dorsal edge of the finfold in preflexion 

 larvae. This dorsal midbody patch recedes toward the 

 body and splits into two somewhat triangular-shaped 

 patches of pigmentation in flexion larvae. This larger 

 patch of pigmentation is retained on the second dorsal 

 fin in postflexion larvae and juveniles. The finfold 

 patches roughly correspond to body bands on postflexion 

 and juvenile specimens. Three additional triangular- 

 shaped patches of melanophores are present approxi- 

 mately two-thirds of the distance between the anus 

 and notochord tip on the dorsal finfold and form a 

 continuous region of pigment extending to the caudal 

 finfold. The triangular-shaped patches of pigmentation 

 separate in flexion larvae and disappear as the finfold 

 recedes in postflexion larvae. 



