Munroe: Systematics of western Atlantic Symphurus 
127 
posteriorly, not reaching anterior margin of lower eye. 
Jaws long; posterior margin of maxilla usually reach- 
ing to vertical through middle of pupil of lower eye 
or sometimes to vertical through posterior margin of 
pupil of lower eye. Ocular-side lower jaw with dis- 
tinct, fleshy ridge near posterior margin (Fig. 3D). 
Teeth well developed on blind-side jaws. Margin of 
ocular-side dentary with single row of slender teeth 
on anterior one-third of jaw. Anterior one-third of 
ocular-side premaxillary margin with only short row 
of teeth, or occasionally, lacking teeth altogether. 
Chin depth somewhat larger than snout length. 
Lower eye relatively small; eyes slightly subequal in 
position with upper slightly in advance of lower eye. 
Anterior and medial surfaces of eyes not covered with 
scales; usually 1-3 small ctenoid scales in narrow 
interorbital space. Pupillary operculum absent. Dor- 
sal-fin origin (Fig. 3D) usually situated at vertical 
anterior to anterior margin of upper eye; occasion- 
ally only reaching vertical through anterior margin 
of pupil of upper eye. Scales usually absent on blind 
sides of dorsal- and anal-fin rays; occasionally with 
1-3 small scales at bases of fin rays, but without 
scales distally on fin rays. Pelvic fin short; longest 
pelvic-fin ray, when extended posteriorly, usually 
reaching base of first, or occasionally second, anal- 
fin ray. Posteriormost pelvic-fin ray connected to body 
by delicate membrane terminating immediately an- 
terior to anus, or occasionally extending posteriorly 
almost to anal-fin origin (membrane torn in most 
specimens). Caudal fin short. Scales large, ctenoid 
on both sides of body. 
Pigmentation (Fig. 56, A-B) Body coloration gen- 
erally similar for both sexes (dichromatic differences 
in pigmentation are discussed below). Ocular surface 
light to dark brown; sometimes with dark brown 
crossbands continuous across head and body. 
Crossbands, when developed, narrow, 6 to 14 in num- 
ber, sometimes sharply contrasting (especially in 
mature females), otherwise faint and barely percep- 
tible against dark body coloration. Crossbands not 
continued on dorsal and anal fins. First band cross- 
ing head short distance anterior to opercular open- 
ing. Trunk crossbands 3 to 6 scale rows wide. Two 
posteriormost bands immediately anterior to caudal- 
fin base often conjoined. Dorsal margin of outer sur- 
face of ocular-side opercle often with dusky blotch 
due to dark pigmentation of inner lining of opercle 
showing through to outer surface. Inner lining of 
opercle and isthmus on ocular side usually heavily 
pigmented; lining of blind-side opercle and blind-side 
isthmus usually unpigmented. Band of pigmentation 
usually developed on ocular-side upper lip; lower lip 
on ocular side frequently spotted, but usually with- 
out definite band. Blind side off-white. Peritoneum 
unpigmented. 
Pigmentation of dorsal and anal fins generally 
similar in both sexes, but usually more intense in 
males. Dorsal- and anal-fin rays on anterior 
two-thirds of body streaked with brown pigment simi- 
lar in shade and intensity to body color. Fin rays com- 
pletely pigmented other than for unpigmented ex- 
treme distal tips. Membranes of anterior three- 
fourths of fins unpigmented. Caudal fin and dorsal 
and anal fins on posterior one-third of body more 
heavily pigmented and considerably darker than 
anterior two-thirds of fin. Fin membranes on poste- 
rior quarter of body heavily pigmented. Basal one- 
third of caudal fin more lightly pigmented than rest 
of fin. Tips of middle caudal-fin rays unpigmented, 
or with tips of middle caudal-fin rays streaked with 
pigment, but membrane unpigmented. 
Size and sexual maturity (Fig. 9CJ A relatively 
large tonguefish, S. civitatium attains sizes of about 
152 mm. Males and females attain similar sizes. The 
largest fish examined, a female (152 mm), was only 
slightly larger than the largest male ( 149 mm). Most 
specimens ranged in size from 80 to 140 mm. Of 188 
fish for which size-related life history information 
was available, there were 102 males (75.5-149.3 
mm), 86 females (83.4-152 mm), and 10 immature 
fish (22.0-57.3 mm) of indeterminate sex. On the 
basis of reproductive stages of females, this species 
matures at sizes usually larger than 90 mm. Of 86 
females examined, only 3 (83-95 mm) were imma- 
ture. The two smallest gravid females were 80-90 
mm, whereas the majority of gravid females were 
usually larger (91-140 mm). 
Geographic distribution (Fig. 57 J Western North 
Atlantic from Cape Hatteras, North Carolina, to the 
Yucatan Peninsula, Mexico. There is a single record 
for this species from Bermuda (ANSP 137573). In 
the Gulf of Mexico, S. civitatium occurs most com- 
monly west of Apalachicola Bay in northern Florida 
(Springer and Bullis, 1956; Chittenden and McEachran, 
1976; McCaffrey, 1981). It is one of the most commonly 
collected tonguefishes on terrigenous sand substrates 
on the inner continental shelf in the Gulf of Mexico 
from Alabama to Texas (Hildebrand, 1954). Along the 
Mexican coast, this species occurs on sandy substrates 
as far south as coastal lagoons (Lagunas el Carmen y 
La Machona, Laguna de Terminos) in Tabasco and 
Campeche, Mexico (Hildebrand, 1955; Resendez 
Medina, 1979; Alvarez-Guillen et ah, 1985; Yanez- 
Arancibia and Sanchez-Gil, 1986), and on the conti- 
nental shelf of the southern Gulf of Mexico (Cabo Rojo, 
Veracruz, to Sabuncuy, Yucatan Peninsula, Mexico). 
