Munroe: Systematics of western Atlantic Symphurus 
147 
has been recognized as an important transitional 
zone where many groups of shallow-water organisms 
reach their geographic limits (Briggs, 1974). Cape 
Hatteras also delimits the geographic limits of many 
warm-temperate tonguefishes, especially the shal- 
low-water species. Eight tonguefish species occur 
north of Cape Hatteras, or only slightly over half the 
diversity (14 species) recorded immediately south of 
the Cape. However, of these, only S. billykrietei is 
taken more frequently and in greater abundance 
north of the Cape, whereas the other seven species 
are more abundant in collections south of Cape 
Hatteras. Of species occurring north of Cape 
Hatteras, only for S. billykrietei and S. minor are 
adults taken as far north as the continental shelf off 
Nova Scotia. Symphurus billykrietei is the only spe- 
cies whose population(s) is centered north of Cape 
Hatteras, with all but three of the 99 specimens iden- 
tified as this species collected north of this point. 
Adults and larvae of S. minor have rarely been re- 
ported from temperate waters off Nova Scotia 
(Ginsburg, 1951; Markle et al., 1980), but with nearly 
a 100-year gap between the collection of the speci- 
mens. Thus, the occurrence of S. minor in these 
northern waters is unusual and likely represents 
expatriate individuals transported north by the Gulf 
Stream. Symphurus plagiusa reaches its northern 
distributional limit in Long Island Sound off Con- 
necticut (Ginsburg, 1951) but again is not abundant 
north of the Chesapeake Bay region. Symphurus 
nebulosus, a poorly known species, ranges from just 
south of Long Island, New York (40°48'N), to the 
Blake Plateau (26°28'N), but 21 of 27 known speci- 
mens were collected south of Cape Hatteras. 
Symphurus pusillus extends to off Long Island (ca. 
40°N), but only nine of 29 known specimens of this 
poorly known species were collected north of Cape 
Hatteras. Although <S. marginatus ranges into conti- 
nental shelf waters off New Jersey, it is collected more 
frequently and in greater abundance (105 of 110 in- 
dividuals) south of Cape Hatteras (Fig. 33). 
Symphurus diomedeanus (Fig. 47) and S. civitatium 
(Fig. 57) range along the inner continental shelf a 
relatively short distance north of Cape Hatteras, but 
the major populations of both species are located well 
south of this area. 
Eleven Symphurus species occur in warm temper- 
ate areas of the western North Atlantic. Of these, S. 
urospilus and S. civitatium appear to be endemic to 
this region. Except for S. nebulosus and S. minor, 
the other species have extensive distributions 
throughout warm temperate regions ranging from 
Cape Hatteras to southern Florida and through the 
Gulf of Mexico. Symphurus nebulosus is unique in 
being restricted to the outer continental shelf and 
upper continental slope off the eastern United States. 
With the exception of irregularly captured individu- 
als transported north by the Gulf Stream, S. minor 
has a somewhat restricted geographic distribution. 
This species occurs from about Cape Hatteras south 
into the eastern Gulf of Mexico off west Florida, and 
west to the DeSoto Submarine Canyon. It is unknown 
from the western Gulf of Mexico. Of other species 
whose center of abundance is shallower than 100 m 
and that are recorded from the region immediately 
south of Cape Hatteras, only S. plagiusa has a large 
population to the north in Chesapeake Bay. Sym- 
phurus urospilus and S. parvus have their northern- 
most records at Cape Hatteras, with the majority of 
captures of these species occurring farther south and 
in the Gulf of Mexico (both species), or off northern 
South America (S. parvus). Major populations of S. 
plagiusa are found in coastal waters of the south- 
eastern United States and northern Gulf of Mexico. 
Symphurus civitatium is abundant in warm-temper- 
ate waters off the southeastern United States and 
through the central and western Gulf of Mexico. 
Symphurus diomedeanus is also commonly collected 
in this region and farther south. Most (20/29) S. 
pusillus specimens were taken in warm-temperate 
areas along the southeastern United States and Gulf 
of Mexico. Sytnphurus pelicanus has been collected 
in central and western areas of the Gulf, but most 
individuals were collected in the Caribbean. 
Symphurus piger is occasionally taken in the cen- 
tral and eastern Gulf of Mexico, but this species also 
occurs more often in the Caribbean region, including 
the Straits of Florida. Symphurus marginatus is 
found in the eastern and central Gulf of Mexico as 
far west as Louisiana (91°18'W), and throughout the 
Caribbean Sea. Symphurus billykrietei is rarely 
taken in the Gulf of Mexico (two specimens, one from 
the Tortugas area in the eastern Gulf, another off 
Yucatan). 
Twelve species of Symphurus occur in tropical re- 
gions of the western Atlantic with six ( S . arawak, S. 
rhytisma , S. ommaspilus , S. caribbeanus , S. 
stigmosus, and S. oculellus) endemic to this region. 
Symphurus diomedeanus has the most extensive dis- 
tribution of the species occurring in tropical waters, 
occurring from northern warm-temperate areas to 
warm-temperate regions of the South Atlantic. 
Symphurus marginatus is widespread throughout 
the western Atlantic from warm-temperate regions 
of the north to comparable areas in the South Atlan- 
tic. The recent first report ( Seret and Andreata, 1992 ) 
of S. marginatus off tropical Brazil (21°S) reflects 
our limited knowledge of South Atlantic environ- 
ments deeper than ca. 200 m. Intensified sampling 
may reveal other deep-sea tonguefishes in this area. 
