72 
Fishery Bulletin 96(1 ), 1998 
Table 22 
Morphometries for holotype (BMNH 1913.12.4:264) and 19 
additional specimens of Symphurus trewauasae. (Abbre- 
viations defined in methods section; SL is expressed in mm; 
characters 2 to 14 are expressed in thousandths of SL; 15 
to 21 in thousandths ofHL; n = no. of specimens measured.) 
Character 
Holotype 
n 
Range 
Mean 
SD 
1 SL 
117.0 
20 
69.1-131.0 
107.3 
17.17 
2. BD 
310 
19 
267-419 
307.9 
31.01 
3. PDL 
41 
20 
36-50 
41.4 
4.25 
4. PAL 
197 
20 
184-243 
217.1 
15.05 
5. DBL 
959 
20 
952-969 
959.6 
4.35 
6. ABL 
791 
20 
757-812 
783.1 
15.56 
7. PL 
70 
18 
57-80 
68.8 
6.29 
8. PA 
64 
20 
37-83 
60.8 
12.76 
9. CFL 
116 
19 
83-129 
114.2 
13.70 
10. HL 
193 
20 
154-197 
182.0 
10.62 
11. HW 
260 
20 
206-260 
227.2 
15.92 
12. POL 
128 
20 
106-132 
118.7 
8.41 
13. UHL 
170 
19 
122-199 
151.3 
20.28 
14. LHL 
103 
19 
73-123 
100.8 
13.89 
15. POL 
664 
20 
613-696 
651.7 
25.95 
16. SNL 
181 
20 
181-263 
206.0 
22.84 
17. UJL 
186 
20 
186-250 
218.8 
17.72 
18. ED 
124 
20 
114—162 
130.6 
12.67 
19. CD 
159 
20 
159-264 
227.2 
26.08 
20. OPLL 
283 
19 
216-419 
293.6 
46.52 
21. OPUL 
186 
19 
159-297 
227.3 
38.54 
upper lobe. Lower opercular lobe on ocular side usu- 
ally considerably wider than upper lobe. Snout short 
and rounded; covered with small ctenoid scales. Der- 
mal papillae evident, but not highly developed, on 
blind-side snout. Anterior nostril on ocular side short, 
not reaching anterior border of lower eye when de- 
pressed posteriorly. Jaws moderately long; maxilla 
usually extending posteriorly to vertical through 
anterior margin of pupil of lower eye. Ocular-side 
lower jaw without fleshy ridge. Teeth well developed 
on blind-side jaws. Dentary on ocular side with slen- 
der teeth along entire margin; a small number of slen- 
der teeth on anterior one-half to one-third of margin 
of ocular-side premaxilla. Chin depth usually slightly 
larger than snout length. Lower eye relatively large; 
eyes usually equal in position, occasionally eyes 
slightly subequal with upper in advance of lower eye. 
Anterior and medial surfaces of eyes and narrow in- 
terorbital space partially covered with 4-6 small 
ctenoid scales. Pupillary operculum absent. Dorsal- 
fin origin usually equal with, or occasionally slightly 
anterior to, vertical through anterior margin of up- 
per eye; predorsal length long. Scales absent from 
blind sides of dorsal- and anal-fin rays. Pelvic fin 
moderately long; longest pelvic-fin ray, when ex- 
tended posteriorly, usually reaching base of first anal- 
fin ray. Posteriormost pelvic-fin ray connected to body 
by delicate membrane terminating immediately an- 
terior to anus, or occasionally extending posteriorly 
nearly to anal-fin origin (membrane torn in most 
specimens examined). Caudal fin moderately long. 
Scales large, ctenoid; with cteni about equally devel- 
oped on both sides of body. 
Pigmentation (Fig. 36) Body coloration similar for 
both sexes. Ocular surface usually medium to light 
brown or straw-colored, with 3-7 (usually 3-5) com- 
plete, sharply contrasting dark brown crossbands on 
head and body. Crossbands not continued on dorsal 
and anal fins. Crossbands on head and posteriormost 
body usually faint and sometimes incomplete, but 
otherwise usually visible without magnification. 
Usually three conspicuous crossbands on body be- 
tween posterior margin of head and base of caudal 
fin. Anteriormost crossband on body at, or slightly 
posterior to, opercular opening. Ocular-side outer 
opercle with small cluster of brown speckles near 
ventral margin (remnants of incomplete band?). In- 
ner linings of opercles on both sides of body occa- 
sionally lightly pigmented. Isthmus unpigmented on 
both sides of body. Ocular-side upper lip with slight 
band of pigment; lower lip usually only lightly spot- 
ted, without definite pigment band. Blind side uni- 
formly creamy white. Peritoneum unpigmented. 
Dorsal- and anal-fin rays, along entire fins, with 
faint light brown pigment, heaviest on proximal one- 
half of fin rays; fins without blotches or spots. Cau- 
dal fin usually pale throughout entire length, occa- 
sionally scale-covered base of caudal fin darker brown 
than distal, scaleless portion of caudal-fin rays, but 
without well-developed spot. 
Size and sexual maturity (Fig. 8E) Symphurus 
trewavasae is a medium-size species reported to at- 
tain a maximum size of ca. 139 mm (Menezes and 
Benvegnu, 1976). The largest specimens examined 
in this study were males measuring 124, 125, and 
131 mm, with the largest female (123 mm) only 
slightly smaller. Of 48 specimens for which size-re- 
lated life history information was available, 19 were 
males (52.5-131.0 mm) and 29 females (63.7-123.8 
mm). Based on reproductive stages of females, sexual 
maturity in the species occurs at ca. 70-80 mm. All 
but three females larger than 80 mm had fully elon- 
gate ovaries and were either gravid or spent. The 
smallest gravid female was 74 mm. Seven immature 
females ranged from 69.1-122.9 mm. The smallest 
of these (69 and 78 mm, respectively) had ovaries 
just undergoing elongation, whereas ovaries of other 
immature females were partially elongate without 
indications of developing ova. 
