Ditty et al.: A redescription of Chaetodipterus faber larvae 



267 



SUPRAOCCIRTAL 



SUPRAORBITAL 



POSTTEMPORAL 



TABULAR 

 SUPRACLEITHRAL 

 OPERCLE 



CIRCUMORBITALS 



INTEROPERCLE 

 INNER PREOPERCLE 

 OUTER PREOPERCLE 



Figure 2 



Location of head spines on a 7.0-mm SL larva 

 of Atlantic spadefish, Chaetodipterus faber, 

 from the northern Gulf of Mexico. 



neurals) were ossifying by 6.0 mm. The anteriormost 

 precaudal vertebrae and dorsal- and anal-fin 

 pterygiophores ossified first; ossification proceeded 

 posteriorly. All caudal bones were ossifying by 8.0 

 mm. Six branchiostegal rays and 10+14 vertebrae 

 were present in all cleared and stained specimens. 



Fin development 



A continuous median finfold extended around the 

 body from the nape to the anus of early larvae. Fin 

 ray anlagen began forming obliquely downward in 

 the caudal finfold during flexion (usually 3.5-4.5 

 mm). Caudal-fin ray development proceeded out- 

 ward from mid-base as the hypural complex shifted 

 to a terminal position, with the adult complement 

 of 9+8 principal rays attained at about 6.0 mm 

 (Table 2). Development of the dorsal- and anal-fin 

 bases coincided with notochord flexion. Both fin 

 bases and their ray anlagen began to differentiate 

 near mid-fin; development proceeded outward from 

 mid-fin. All dorsal and anal soft rays were present 

 by about 7.0 mm. Soft dorsal and anal fin ray 

 complements were present before their spines (Table 

 2); dorsal and anal spines developed in an anterior 



Figure 3 



Scanning electromicrograph of the frontal and occipital spines of a 7.0-mm SL Atlantic spade- 

 fish, Chaetodipterus faber. Epithelium was partially digested with trypsin to enhance visibility 

 of frontal and occipital spines. Magnification: 140x. 



