Bruce Larval development of Sillaginodes punctata, Sillago bassensis, and Sillago schomburgkn 



35 



Figure 3 



Development of Sillago bassensis. (A) 3.2 mm; (B) 4.4 mm; (C) 4.8 mm; (D) 5.9 mm; (E) 

 7.2 mm; (F) 11.2 mm; (G) 12.7 mm (postsettlement). 



into fore, mid, and hindgut regions. The midgut be- 

 comes rugose by 3.0 mm and remains so, although 

 overlying musculature obscures this feature prior to 

 settlement. The gut begins to coil in preflexion lar- 

 vae by 4.1 mm. Coiling proceeds without migration 

 of the anus and is achieved by elongation and ante- 

 rior looping of the midgut (Fig. 4). Consequently, body 

 proportions do not show a significant change in 



preanal length which remains at 47—48% BL. Coil- 

 ing of the gut is completed in postflexion larvae (7.0- 

 7.5 mm). The gas bladder has its origin at myomeres 

 2-8 in preflexion larvae but migrates posteriorly 

 during development to myomeres 5-10 in postflexion 

 larvae. The gas bladder is inflated and prominent in 

 90% of field-collected larvae (random subsample 

 n=40; all larvae were collected at night). 



