Munroe: Systematics of western Atlantic Symphurus 
1 19 
of 16.4-30.0°C and salinities of 32.8-36.2%e. Three 
specimens had fed on crustaceans, and one had in- 
gested a gastropod. Topp and Hoff (1972) also noted 
that specimens of S. urospilus caught off the West 
Florida Shelf in September had ripe and ripening 
gonads, and a specimen collected in late August had 
developing ova. Their smallest specimen (27 mm) was 
collected in November, further suggesting a late sum- 
mer-early fall spawning period for this species in 
the eastern Gulf of Mexico. Webster et al. 3 collected 
457 individuals (12.8 kg) by trawling in the South 
Atlantic Bight. In their study, this species ranked 
70th in abundance of 244 taxa collected. 
Geographic variation Only slight variation was 
evident in meristic features (Table 33) examined in 
specimens from three different regions of the geo- 
graphic range. Symphurus urospilus from off the 
southeastern United States and western Gulf of 
Mexico had similar counts for dorsal- and anal-fin 
rays and total vertebrae. Counts for these features 
were consistently higher in specimens from these 
Table 33 
Geographic variation in selected meristic features of Sym- 
phurus urospilus. Abbreviations: SEUS = southeastern 
United States; EGMX = eastern Gulf of Mexico; WGMX = 
western Gulf of Mexico including Yucatan shelf region; n = 
no. of specimens measured. 
Character 
n 
Area 
Mean 
Range 
SD 
Dorsal rays 
20 
SEUS 
86.6 
84-90 
1.35 
70 
EGMX 
85.0 
82-88 
1.24 
26 
WGMX 
87.3 
84-89 
1.25 
Anal rays 
20 
SEUS 
70.4 
67-72 
1.14 
70 
EGMX 
69.0 
64-71 
1.27 
26 
WGMX 
71.0 
68-74 
1.37 
Vertebrae 
20 
SEUS 
45.8 
45-47 
0.52 
70 
EGMX 
45.2 
44-46 
0.51 
26 
WGMX 
46.3 
45-48 
0.60 
regions than were those for S. urospilus from the 
eastern Gulf of Mexico. 
Comparisons Symphurus urospilus is one of the 
most distinctive species in the genus. Its unique com- 
bination of 11 caudal-fin rays, pupillary operculum, 
spotted caudal fin, and ID pattern distinguishes this 
species from all congeners. Other western Atlantic 
species with spotted fins differ in caudal-fin ray count 
(S. diomedeanus and S. ommaspilus have 10 cau- 
dal-fin rays) and either lack a caudal spot altogether, 
or if a caudal spot is present (occasionally in S. 
diomedeanus ), there are spots present also on the 
dorsal and anal fins. Other differences between S. 
urospilus and these species are discussed in the 
“Comparisons” sections in accounts for S. ommaspilus 
and S. diomedeanus. 
The eastern Pacific S. melasmatotheca and S. 
undecimplerus, the only other congeners with 1 1 cau- 
dal-fin rays, also have a pupillary operculum. 
Symphurus urospilus differs from both in peritoneal 
color (unpigmented vs. black or spotted in these other 
species), its spot on the caudal fin (absent in these 
others), in its mostly nonoverlapping fin-ray and ver- 
tebral counts (82-90 dorsal-fin rays vs. 90-98 in S. 
melasmatotheca and 97-105 in S. undecimplerus ; 64- 
74 anal-fin rays vs. 74-80 in S. melasmatotheca and 
80-87 in S. undecimplerus ; and 44-48 total verte- 
brae vs. 49-52 in S. melasmatotheca and 52-56 in S. 
undecimplerus), and ID pattern (1-4-3 vs. 1-5-3 in 
these others). 
The eastern Pacific species, <S. fasciolaris, also has 
a prominent spot on the caudal fin and a 1-4-3 ID 
pattern reminiscent of features in S. urospilus. De- 
spite these similarities, these are otherwise distinc- 
tive species differing in many characteristics. 
Symphurus fasciolaris has 10 caudal-fin rays, more 
dorsal- (90-97) and anal-fin rays (75-80), and more 
total vertebrae (48-52) than does S. urospilus. Addi- 
tionally, this species usually has a series of rounded 
spots in addition to crossbands on the ocular sur- 
face, whereas S. urospilus lacks rounded spots on 
the ocular surface. 
