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Fishery Bulletin 98(3) 



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Body Length (BL) mm 



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Figure 7 



Comparison of body depth ratios among larvae of L. aiialis, L. campechanus, L. griseus, L. synagris, O. 

 chrysurus, and R. aurorubens. 



provide important diagnostic characters. Flexion larvae of 

 O. chrysurus, L. analis, and L. synagris are shallow-bodied 

 ranging from 239/ to 29'7r of body length (Fig. 7). whereas 

 body depth in flexion larvae of L. campechanus. L. griseus, 

 and R. aurorubens is from 34'7( to 36'7f of body length. 

 The approximately equal length of the longest pelvic-fin 

 ray and pelvic spine helps distinguish R. aurorubens and 

 L. griseus from O. chrysurus. L. synagris, L. analis, and 

 L. campechanus larvae in which the longest pelvic ray is 

 nearly twice the length of the pelvic spine. 



Small prefiexion larvae of L. campechanus can be con- 

 sistently distinguished from larvae of R. aurorubens in 

 northcentral GOM waters by the presence of the avm 

 melanophore. This character first appeared in reared speci- 

 mens at 3.4 mm but would be seen in somewhat smaller 

 wild specimens because of the shrinkage experienced by 

 net-captured larvae (Theilacker, 1980). Larvae of O. chrys- 

 urus, L. synagris. and L. analis also develop avm pigment 

 at BLs between ~3 and 4 mm. The presence or absence of 

 this character in L. griseus larvae could not be ascertained 

 from published illustrations (Richards and Saksena, 1980), 

 but avm pigment was present in all specimens of L. gri- 

 seus that we examined. The presence of serrations on 

 the angle spine of the preopercle in R. aurorubens larvae 

 at sizes >3.4 mm distinguishes them from O. chrysurus 

 and all Lutjanus larvae currently known in the GOM. 

 Snapper larvae may develop serrations on the median fin 

 spines to some degree or another, but at least three spe- 

 cies of lutjanine snappers {Hoplopagrus gunteri, L. novem- 

 fasciatus, and L. peru) from the Pacific do not develop 

 serrations on any fin spines (Brogan, 1996; Watson and 

 Brogan, 1996). Larvae of the six species compared in Table 

 5 develop serrations on the pelvic spine and all species. 



except L. campechanus, develop serrations on dorsal-fin 

 spines. Although not shown in the illustrations of Richards 

 and Saksena (1980), the lan'ae of L. griseus do develop 

 pronounced serrations on both dorsal and pelvic spines 

 (Clarke et al, 1997; Richards et al., 1994). The relative 

 size and extent of these serrations vary among species; 

 R. aurorubens has the stoutest serrations among snapper 

 larvae on both the leading and trailing edges of the spines 

 (Laroche. 1977). 



The postanal series of melanophores (pav) along the 

 ventral midline is characteristic of many percoid larvae, 

 including those of snappers. In snapper larvae, postanal 

 pigmentation decreases dramatically during the flexion 

 stage. Despite the dynamic nature of this pigment during 

 development and the considerable overlap in number of pav 

 melanophores among prefiexion larvae (Table 5), Clarke et 

 al. (1997) suggested that the "usual" number (not overall 

 range) of pav melanophores would distinguish the lai"vae 

 of L. synagris and L. analis from each other Yolksac and 

 prefiexion larvae of these two species are further distin- 

 guished from other known lutjanine larvae by the pres- 

 ence of an enlarged melanophore in the pav series (Clarke 

 et al., 1997). An additional pav-related character that dif- 

 fers among known lutjanine larvae is the gap in the pav 

 series posteriorly, as seen in R. aurorubens, L. campecha- 

 nus, and L. analis. The pav series of melanophores in L. 

 griseus, O. chrysurus, and L. synagris is continuous in pre- 

 fiexion larvae. 



Pigmentation associated with the notochord can be used 

 to distinguish the larvae of O. chrysurus. L. synagris, 

 and L. analis from other described GOM lutjanine larvae 

 (Table 5). Although pigment overlying the point of noto- 

 chord flexure develops by ~6 mm in all described GOM 



