COLUNS ET AL,: LARVAL AND JUVEMLE RED SNAPPER 



Spines were found on the preopercle, pos- 

 terodorsal margin of the operculum, posttemporal, 

 and supracleithrum. Serrations developed on the 

 supraocular crest. 



The preopercular spines developed in two rows, 

 one anterior to the preopercular margin and one 

 along the preopercular margin (Figures 1, 2). Both 

 rows had vertical and horizontal segments. The 

 vertical segments were situated approximately 

 perpendicular to the body midline, and the hori- 

 zontal segments were situated approximately 

 parallel to the body midline of the fish. The ante- 

 riormost row had 3-6 spines (1-3 vertically and 2-3 

 horizontally) in the 4.0-22.4 mm specimens. The 

 number of anterior row spines decreased in the 

 largest specimens. The row along the preopercular 

 margin had 5-27 spines (2-18 vertically and 3-9 

 horizontally) in the 4.0-22.4 mm specimens. The 

 number of both vertical and horizontal preopercu- 

 lar margin spines increased between 12.4 and 22.4 

 mm. Vertical spines increased by 16 and horizon- 

 tal spines increased by 4 along the preopercular 

 margin between these two lengths. 



A small spine was present on the interopercle 

 of all specimens. A larger spine was also present 

 on the posterodorsal margin of the opercle of all 

 specimens. ( Figures 1,2). The spine at the angle of 

 the preopercle was the largest spine on the head. 

 No serrations developed on this or any other 

 preopercular spine. 



A spine on the posttemporal was first present on 

 the 7.3 mm larva. A second spine developed on this 

 bone by 9.5 mm. These 2 posttemporal spines 

 were greatly reduced in the two largest specimens. 

 A supracleithral spine was present on the smallest 

 larva (4.0 mm). Three spines were present by 4.2 

 mm, and 5 spines had developed by 9.5 mm (Fig- 

 ures lA, B; 2A). The 2 most ventral supracleith- 

 ral spines were longer in the 12.4 mm specimen 

 than in smaller specimens. The 22.4 mm juvenile 

 had all of the supracleithral spines, but these 

 spines were much smaller (Figure 2C). 



Two serrations developed on the supraocular 

 crest by 7.3 mm (Figure ID), and two more by 12.4 

 mm. The 22.4 specimen had no serrations on the 

 supraocular crest (Figure 2C). 



Eye diameter was 11.0-14.3% SL (Table 4). The 

 eye was almost spherical, and the iris had a ven- 

 tral cleft in all but the largest specimen (Figures 1, 

 2). 



Teeth were present in all specimens on the den- 

 tary and premaxillary bones. In addition, the two 

 largest specimens (12.4 and 22.4 mm) had vo- 



TaBLE 5. — Predictive linear regressions of body measurements 

 on standard length for 24 larval and juvenile Lutjanus cam- 

 pechanus over the size range 4.0-22.4 mm SL. 



Measurement 



Slope 



Intercept 



Head length 

 Body depth 

 Snout to anus length 

 Eye diameter 



0341 

 0699 

 0359 

 0,118 



0350 

 •0 601 

 197 

 0.050 



177 

 159 

 181 

 0054 



0991 

 0998 

 0,992 

 0.993 



merine and palatine teeth. The vomerine teeth in 

 these two specimens were arranged in a V-shaped 

 pattern with the angle pointed anteriorly. 



Body Growth 



Measurements of four body parts are given in 

 Table 4. The growth of these parts in relation to 

 standard length is described by linear regressions 

 (Laroche 1977; Sokal and Rohlf 1969), the statis- 

 tics for which are presented in Table 5. All rela- 

 tionships have high correlation coefficients of 

 S0.991. 



Comparison With 

 Other Lutjanid Larvae and Juveniles 



As stated earlier, R. aurorubens is the only lu- 

 tjanid to have previously had its larval and juve- 

 nile stages described. The two snappers are easily 

 separated as follows: In specimens ^4.0 mm, R. 

 aurorubens has serrations on the largest spine at 

 the preopercular angle. Figure lA in Laroche 

 ( 1977) did not show the serrations on this spine, 

 however, the text stated that, "A large, stout, and 

 serrated spine occurs at the preopercular angle in 

 all specimens." Laroche^ confirmed this. In addi- 

 tion, large serrations develop on the anterior and 

 posterior margins of the dorsal and pelvic spines in 

 larval/?, aurorubens &4.7 mm. None of the 4.0-4.7 

 mm L. campechanus had serrated preopercular, 

 dorsal, or pelvic spines. Both species have serrated 

 pelvic spines in specimens >4.8 mm, but R. au- 

 rorubens has large serrations on the anterior and 

 posterior margins while L. campechanus has 

 small serrations on just the anterior margin. The 

 total number of rays in the dorsal and anal fins 

 also separates these two snappers at sizes s=5.0 

 mm. Rhomboplites aurorubens has 22 or 23 dorsal 

 and 11 anal rays while L. campechanus has 24 

 dorsal and 12 anal rays. Rhomboplites aurorubens 

 is the only lutjanid to have an adult complement of 



'W. A. Laroche, School of Oceanography, Oregon State Uni- 

 versity, Corvallis, OR 97331, pers. commun. June 1978. 



973 



