Munroe: Systematics of western Atlantic Symphurus 
5 
from the Caribbean Sea and more northern areas, 
whereas S. pterospilotus (=S. diomedeanus\ see 
Menezes and Benvegnu, 1976; this study) was de- 
scribed from a single specimen taken off Uruguay. 
In addition to describing new species, Ginsburg di- 
agnosed the genus, evaluated taxonomic characters 
considered important for identifying tonguefishes, 
and updated information on distributions and diag- 
nostic features for all 15 nominal species that he 
recognized. 
Despite these important contributions, Ginsburg’s 
study was limited because his treatment (particu- 
larly of deep-sea, southern Caribbean Sea, and South 
Atlantic species) was constrained by insufficient 
material. In addition, Ginsburg relied almost exclu- 
sively on external characters (primarily fin-ray 
counts) to identify and diagnose his specimens and 
therefore was unable to resolve problems involving 
externally phenetically similar species that differ 
unambiguously in internal characters, such as in- 
terdigitation patterns and vertebral numbers 
(Munroe, 1987). 
Soon after Ginsburg’s revision, two species ( S . 
ommaspilus and S. rhytisma) of shallow-water, dwarf 
tonguefishes were discovered in the Caribbean on 
patches of sand adjacent to coral reefs (Bohlke, 1961). 
In 1965, Robins and Randall described S. arawak, a 
third species of dwarf tonguefish collected in similar 
habitats. 
The first significant revision of western South At- 
lantic tonguefishes was by Menezes and Benvegnu 
( 1976), who studied primarily tonguefishes occurring 
along the eastern coast of South America, although 
including comparative material from elsewhere in 
the western Atlantic whenever possible. Two new 
species (S. kyaropterygium and S. ginsburgi ), col- 
lected from moderate depths on the continental shelf 
off southern Brazil, were described in their work, and 
S. pterospilotus Ginsburg was placed in the syn- 
onymy ofS. diomedeanus (Goode and Bean). Menezes 
and Benvegnu’s study complemented that of 
Ginsburg (1951), but the regional nature and lim- 
ited study material of this revision prevented reso- 
lution of the status of several nominal species of 
western Atlantic tonguefishes. 
In 1977, Lema and Oliveira published a key to 
western Atlantic species of Symphurus , based almost 
entirely on information (primarily counts of fin rays) 
gathered from published literature accounts. In ad- 
dition to their identification key, these authors dis- 
cussed the distribution of symphurine tonguefishes 
in southern Brazilian waters and described S'. 
meridionalis ( =S . jenynsi, see below) from shallow 
waters on the inner continental shelf off southern 
Brazil. 
The most recent systematic treatment of Atlantic 
symphurine tonguefishes is that of an unpublished 
dissertation (Munroe, 1987), in which 23 species, 
including three new ones, were recognized in the 
western Atlantic. Five of these 23, including two 
undescribed species (now S. oculellus and S. 
caribbeanus), represent the Atlantic members of the 
S. plagusia complex and were documented earlier 
(Munroe, 1991). The present study expands upon 
earlier research on this group of fishes. It includes 
one previously undescribed species in addition to 
those reported in Munroe (1987), and it provides 
additional information on Atlantic members of the 
S. plagusia complex. 
Western Atlantic tonguefishes belong to the same 
species groups as eastern Atlantic and eastern Pa- 
cific tonguefishes, and several species pairs, compris- 
ing a western Atlantic species and another species 
from these areas, are hypothesized. No western At- 
lantic Symphurus species occur in these other areas; 
therefore, detailed comparisons distinguishing west- 
ern Atlantic tonguefishes from species occurring in 
other geographic regions are provided only among 
phenetically similar species or hypothesized species 
pairs. Comparative information on eastern Atlantic 
tonguefishes is found in Munroe (1990, 1992), 
whereas Munroe and Mahadeva (1989), Mahadeva 
and Munroe (1990), Munroe and Nizinski (1990), 
Munroe et al. ( 1991), Munroe ( 1992), and Munroe et 
al. (1995) provide data for eastern Pacific tongue- 
fishes. Among western Atlantic tonguefishes, only S. 
nebulosus has a pterygiophore interdigitation pat- 
tern (1-2-2) commonly found in Indo-West Pacific 
tonguefishes (Munroe, 1992). Therefore, all western 
Atlantic tonguefishes, except S. nebulosus, are readily 
distinguished from those of the Indo-West Pacific 
region by differences in ID patterns (Munroe, 1992), 
and no further comparisons between species from 
western Atlantic and Indo-Pacific regions are neces- 
sary to distinguish the species. 
Methods and materials 
Counts and measurements (Figs. 1-5J 
Descriptions of pigmentation are based on formalin- 
fixed fishes stored in alcohol. In text and tables 
(whenever possible), species that share a common 
interdigitation pattern (Fig. 1, A-E) are grouped to- 
gether and arranged alphabetically within this 
grouping. The order of presentation begins with S. 
nebulosus , the only western Atlantic species with a 
1-2-2 interdigitation pattern; then follow species with 
the 1-3-2 pattern, unpigmented peritoneum, and four 
