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Fishery Bulletin 96( 1 ), 1998 
species by differences in meristic characters (see 
Tables 4-7). These and other differences are dis- 
cussed in the “Comparisons” section of the species 
accounts for S. kyaropterygium and «S. minor). 
Symphurus parvus differs most notably from S. 
ommaspilus in having an irregularly shaped, dark 
brown, blotch on the ocular-side caudal region and 
in having uniformly pigmented dorsal and anal fins, 
whereas S. ommaspilus lacks the pigmented blotch 
on the ocular-side caudal region, and it has a single, 
conspicuous, ocellated spot on the posterior dorsal 
and anal fins. Other differences between these spe- 
cies include modal differences in meristic features 
(see Tables 4-7). 
Symphurus parvus is similar in size and some 
meristic features to, and also occurs syntopically 
with, S. pelicanus. Symphurus parvus differs readily 
from this species in having an unpigmented perito- 
neum, dark brown blotch on the ocular-side caudal 
region, pupillary operculum, and 10 caudal-fin rays 
(vs. black peritoneum, no caudal blotch, no pupillary 
operculum, and 12 caudal-fin rays in S. pelicanus). 
Other differences between S. parvus and S. pelicanus 
are discussed in the “Comparisons” section of the ac- 
count for S. pelicanus. 
Symphurus parvus is not easily confused with 
other Atlantic tonguefishes possessing 10 caudal-fin 
rays (S. plagiusa, S. jenynsi, and 8. diomedeanus), 
which have either sympatric or similar bathymetric 
distributions and which may be collected syntopically, 
because S. parvus has much lower meristic features 
(see Tables 4-9), membrane ostia in dorsal and anal 
fins, and a dark brown caudal blotch on the ocular side 
(vs. higher meristics, caudal blotch, and membrane os- 
tia lacking in these other species). Symphurus parvus 
differs further from the sympatric S. plagiusa and the 
allopatric S. jenynsi in having a well-developed pupil- 
lary operculum (absent in these others). Symphurus 
parvus also lacks the conspicuous black spot on the 
outer surface of the ocular-side opercle, fleshy ridge on 
the ocular-side lower jaw, and small ctenoid scales on 
blind sides of the posterior dorsal- and anal-fin rays 
characteristic of 8. plagiusa. Symphurus parvus is also 
easily recognized from S. diomedeanus because it has 
uniformly pigmented dorsal and anal fins lacking con- 
spicuous spots, whereas dorsal and anal fins of S. 
diomedeanus usually have a series of conspicuous spots 
on posterior regions of these fins. 
Symphurus parvus is readily distinguished from 
eastern Pacific congeners by its combination of a 
1-4-2 ID pattern, 10 caudal-fin rays, unpigmented 
peritoneum, and well-developed pupillary operculum. 
Among these species, only S. fasciolaris has 10 cau- 
dal-fin rays. Symphurus parvus differs from this spe- 
cies in its lower counts (43-47 vs. 48-52 total verte- 
brae; 75-86 vs. 90-97 dorsal-fin rays; and 60-70 vs. 
77-81 anal-fin rays in S. fasciolaris). It also lacks 
the pigmented spot on the caudal fin and combina- 
tion of crossbands and rounded spots on the ocular 
surface present in S. fasciolaris. 
