Munroe: Systematics of western Atlantic Symphurus 
63 
Table 20 
Morphometries for holotype (MCZ 27967) and 29 additional 
specimens of Symphurus marginatus. (Abbreviations de- 
fined in methods section; SL is expressed in mm; charac- 
ters 2 to 14 are expressed in thousandths of SL; 15 to 21 in 
thousandths of HL; n = no. of specimens measured.) 
Character 
Holotype 
n 
Range 
Mean 
SD 
1. SL 
90.1 
30 
56.9-146.1 
106.5 
18.08 
2. BD 
218 
30 
200-315 
250.3 
27.14 
3. PDL 
58 
30 
44-81 
56.0 
7.33 
4. PAL 
203 
30 
182-256 
219.1 
17.40 
5. DBL 
942 
30 
919-956 
944.0 
7.34 
6. ABL 
741 
30 
616-846 
768.2 
34.22 
7. PL 
— 
24 
42-74 
58.0 
8.24 
8. PA 
50 
30 
27-74 
52.9 
11.50 
9. CFL 
— 
25 
80-125 
105.9 
11.46 
10. HL 
192 
30 
127-221 
182.1 
15.56 
11. HW 
196 
30 
147-227 
191.2 
16.74 
12. POL 
119 
30 
99-144 
112.0 
8.88 
13. UHL 
90 
30 
90-133 
110.3 
11.86 
14. LHL 
115 
30 
84-129 
97.1 
11.08 
15. POL 
618 
30 
571-802 
617.0 
41.52 
16. SNL 
185 
30 
168-331 
207.2 
31.91 
17. UJL 
231 
30 
180-331 
213.6 
25.77 
18. ED 
150 
30 
125-248 
148.6 
22.98 
19. CD 
144 
30 
144-256 
197.4 
30.83 
20. OPLL 
300 
30 
208-372 
290.4 
36.30 
21. OPUL 
156 
30 
144-331 
218.9 
38.03 
posteriorly beyond this point. Body depth increasing 
with size, juveniles with narrower body, usually pro- 
portionately less than 280 SL; adults with body depth 
ranging from 280-315 SL. Preanal length slightly 
shorter than body depth. Head moderately long and 
relatively narrow, slightly shorter than body depth. 
Head usually just slightly wider than long (HW:HL 
0.84-1.25, x =1.05). Lower head lobe narrow, slightly 
less than postorbital length; slightly narrower than 
upper head lobe. Lower opercular lobe of ocular side 
considerably wider than upper lobe. Snout short, 
somewhat pointed; covered with small ctenoid scales. 
Poorly developed dermal papillae occasionally 
present on blind-side snout. Anterior nostril on ocu- 
lar side long, when depressed posteriorly, usually 
falling just short of anterior border of lower eye (about 
two-thirds of specimens), or just reaching to ante- 
rior border of lower eye in about one-third of speci- 
mens. Jaws moderately long; maxilla extending pos- 
teriorly to vertical through anterior margin of lower 
eye. Ocular-side lower jaw without fleshy ridge. Teeth 
well developed on blind-side jaws. Ocular-side 
dentary with row of teeth along complete margin of 
jaw; ocular-side premaxilla usually with single row 
of teeth along anterior four- fifths of margin of jaw, 
occasionally with complete tooth row. Chin depth 
slightly smaller than snout length. Lower eye large; 
eyes usually equal in position, with large and obvi- 
ous lens. Anterior and medial surfaces of eyes par- 
tially covered with 4-6 small ctenoid scales; 4-6 small 
ctenoid scales in narrow interorbital region. Pupil- 
lary operculum absent. Dorsal-fin origin usually 
equal with vertical through midpoint of upper eye, 
occasionally located more posteriorly, only reaching 
vertical through posterior margin of upper eye. Scales 
absent on blind sides of dorsal- and anal-fin rays. 
Pelvic fin short; longest pelvic-fin ray, when extended 
posteriorly, usually reaching base of first anal-fin ray. 
Posteriormost pelvic-fin ray connected to body by 
short delicate membrane terminating anterior to anus, 
or occasionally reaching posteriorly to anal-fin origin 
(membrane torn in most specimens). Caudal fin short. 
Relatively small ctenoid scales on both sides of body. 
Pigmentation (Fig. 32J Coloration similar for both 
sexes. Ocular surface usually uniformly dark brown, 
sometimes with yellowish tint, without crossbands. 
The most consistent and obvious pigmentation in 
preserved specimens are longitudinal black stripes 
along bases of the dorsal and anal fins, and a dark 
brown blotch, roughly circular in outline, usually 
covering the entire ocular-side caudal region. Cau- 
dal blotch usually extending over ca. 10 scale rows 
and 13-14 posteriormost fin rays of dorsal and anal 
fins; occasionally caudal blotch extended onto cau- 
dal-fin base. Ocular-side outer opercle with back- 
ground coloration of body. Inner linings of opercles 
and isthmus on both sides of body usually unpig- 
mented. Ocular-side upper lip with variably pig- 
mented band; ocular-side lower lip occasionally spot- 
ted, but without prominent pigment band. Small 
patch of pigment of variable intensity occasionally 
at base of anterior nostril. Blind side off-white, or 
yellowish. Peritoneum black, usually visible through 
abdominal wall on both sides. Anal pore white. 
Basal one-half of dorsal- and anal-fin rays in ante- 
rior two-thirds of body uniformly pigmented with 
dark brown or black pigment forming longitudinal 
stripe along fin-ray bases; distal one-half of those fin 
rays unpigmented or only lightly pigmented with 
diffuse melanophores. Caudal region of body, espe- 
cially proximate to caudal blotch, with fin rays of dor- 
sal and anal fins heavily pigmented. Caudal fin usu- 
ally heavily pigmented on proximal one-half; distal 
one-half with diffuse pattern of light melanophores 
of similar coloration to anterior two-thirds of ocular- 
side of body, or occasionally unpigmented. 
Size and sexua! maturity (Fig. 8C} Symphurus 
marginatus is a medium-size tonguefish attaining 
maximum lengths of about 146 mm. Most specimens 
were much smaller; nearly one-half of 93 specimens 
