50 
Fishery Bulletin 108(1 ) 
Table 4 
Morphometric proportions of larval and juvenile spotfin tonguefish ( Symphurus oligomerus) by percentage of body length (BL, 
mm): eye diameter (ED), head length (HL), caudal region length (CRL), snout-anus length (SAL), body depth at pelvic fin base 
(BD), body depth at anal fin (BDA), loop intestinal length (LIL), abdominal projection length (APL), conical appendix length 
(CAL), nd = not determined. 
% of BL 
Development stage 
BL(mm) 
ED 
HL 
CRL 
SAL 
BD 
BDA 
LIL 
APL 
CAL 
Start of preflexion 
1.6 
6.09 
21.79 
51.15 
48.72 
18.27 
7.31 
31.67 
29.23 
2.44 
2.5 
7.55 
18.67 
64.15 
35.85 
16.98 
8.49 
23.58 
18.87 
4.72 
2.6 
7.28 
21.84 
63.22 
36.78 
17.24 
8.39 
27.36 
21.84 
5.52 
3.0 
6.41 
19.24 
59.01 
41.05 
21.81 
10.26 
21.81 
17.96 
3.85 
3.4 
8.04 
22.86 
61.43 
38.57 
22.86 
11.43 
30.00 
20.00 
10.00 
3.8 
7.59 
22.78 
64.56 
35.34 
25.32 
12.66 
25.32 
15.19 
10.13 
6.8 
4.71 
24.71 
62.35 
38.82 
29.41 
18.82 
23.53 
16.47 
7.06 
7.0 
5.75 
22.99 
59.77 
39.08 
29.89 
18.39 
27.59 
20.69 
6.90 
Start of flexion 
7.1 
5.04 
16.53 
62.18 
37.82 
32.77 
20.17 
22.69 
14.29 
8.40 
7.4 
5.38 
31.18 
59.14 
40.86 
32.26 
17.20 
nd 
19.35 
nd 
7.8 
5.10 
27.55 
60.20 
39.80 
34.69 
18.37 
28.78 
18.98 
9.80 
8.8 
4.55 
23.64 
65.45 
34.55 
23.64 
20.00 
nd 
nd 
nd 
10.0 
4.60 
25.29 
60.92 
39.08 
33.33 
19.54 
34.43 
21.79 
12.64 
10.4 
4.44 
26.67 
60.00 
40.00 
32.22 
19.44 
33.33 
22.22 
11.11 
10.4 
4.59 
25.69 
63.30 
36.70 
33.03 
21.10 
30.28 
21.10 
9.17 
10.6 
4.35 
26.09 
60.87 
39.13 
31.52 
20.65 
28.26 
17.39 
10.87 
11.3 
4.08 
27.55 
59.18 
40.82 
32.65 
19.39 
34.69 
22.45 
12.24 
12.0 
3.85 
25.00 
61.54 
38.46 
28.85 
19.23 
28.76 
21.40 
7.36 
12.3 
3.74 
24.30 
62.62 
37.38 
32.71 
22.43 
24.30 
14.95 
9.35 
14.6 
3.29 
25.20 
60.66 
39.37 
29.13 
21.26 
24.53 
17.32 
7.21 
Start of postflexion 
18.0 
3.19 
24.88 
65.06 
35.08 
27.43 
18.50 
24.24 
19.13 
5.10 
Start of juvenile 
15.8 
3.81 
21.90 
67.15 
32.85 
24.09 
20.44 
15.93 
11.68 
4.25 
18.0 
3.20 
19.22 
73.04 
27.55 
22.42 
20.50 
18.2 
3.80 
27.84 
66.44 
33.54 
22.15 
16.45 
(Fig. IB). Notochord flexion begins in larvae larger than 
7 mm BL and ends near 15 mm BL (Table 3). In the only 
postflexion larva collected (18 mm BL), the right eye had 
begun to migrate to the left side of the head (Fig. 2A). 
In the juvenile stage (15.8-18.2 mm BL) the protruding 
gut is incorporated within the ventral body profile and 
migration of the right eye is complete. Most of the body 
of the juvenile has very small ctenoid scales; each scale 
has a single denticle; the swim bladder, pectoral fins, 
and the conical appendix are no longer visible; and head 
length is 25% of the BL. 
Pigmentation Preflexion larvae (1. 6-3.0 mm BL) typ- 
ically have three equidistant blotches on the distal 
margin of the dorsal fin fold, located approximately 
between myomeres 6-9, 16-19, and 28-33, and an addi- 
tional blotch located on the dorsal margin of the body 
between myomeres 28 and 33. There are two blotches 
present on the distal margin of the anal fin fold and two 
blotches on the ventral margin of the body located at 
myomeres 16-19 and at myomeres 27-36. Several small 
star-shaped melanophores form a line along the ventral 
margin of the intestinal sac, nine similar melanophores 
are present on the left side of the gut, and three or four 
melanophores are present on the left side of the conical 
appendix (Fig. 1A). 
Larvae 3. 4-3. 8 mm BL have a pigmentation pattern 
similar to that described above, but with slight changes 
in the numbers of myomeres forming the blotches (Fig. 
IB); pigmentation is also more intense on the ventral 
area of the intestinal sac, where eight small star-shaped 
melanophores are located nearly at the distal margin 
of the left side of the anus. Small star-shaped melano- 
phores are also present on the pectoral fins: three or 
more on the distal margin of the surrounding mem- 
brane of the pectoral fins, two or more on the distal 
region of the pectoral fin bud, and one on the pectoral 
fin base. Four similar melanophores are present on the 
swim bladder and several dot-like melanophores form 
a discontinuous line along the ventral margin of the 
axial musculature that does not reach the tip of the 
notochord (Fig. IB). 
Conspicuous at flexion stage are three vertical bands 
of star-shaped melanophores aligned perpendicular 
