Munroe: Systematics of western Atlantic Symphurus 
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Artificial key to western Atlantic Symphurus 
la Caudal-fin rays 14 (rarely 13); dorsal-fin rays more than 104; anal-fin rays 91-98; peritoneum 
black, usually visible through abdominal wall on both sides of body; body elongate, of nearly 
uniform width throughout most of its length (Fig. 10); total vertebrae 57-60; ID pattern usually 
1-2-2 (Fig. 1A) So nehulosus 
lb Caudal-fin rays less than 13 (rarely 13); dorsal-fin rays usually less than 104; anal-fin rays 
less than 91; peritoneum black or unpigmented; body usually deeper in anterior one-third of 
length and tapering noticeably posteriorly; total vertebrae less than 57; ID pattern with 3 or 4 
pterygiophores inserted into second interneural space (usually 1-3-2, 1-3-3, 1-4-2, or 1-4-3) 
(Fig. 1, B-E) 2 
2a Peritoneum black, usually visible through abdominal wall on both sides of body; caudal-fin 
rays usually 12; pupillary operculum absent (Fig. 3B); teeth present on entire margins of 
ocular-side jaws; ID pattern usually 1-3-2 (see Fig. IB) 3 
2b Peritoneum unpigmented; caudal-fin rays 10-12; pupillary operculum present (Fig. 3A) or 
absent (Fig 3B); teeth present or absent over entire margins of both ocular-side jaws; ID 
pattern usually 1-3-2 (Fig. IB), 1-3-3 (Fig. 1C), 1-4-2 (Fig. ID), or 1-4-3 (Fig. IE) 9 
3a Blind side of body with pepper-dot pattern of melanophores (usually heaviest along bases 
of dorsal and anal fins) (Fig. 5B, number 8); dorsal-fin rays 77-85; anal-fin rays 64-70; 70 
or fewer scales in longitudinal series; dorsal-fin origin in posterior position, usually only reaching 
vertical through posterior margin of upper eye or occasionally not reaching that point; dorsal 
and anal fins without pigmented blotches or stripes; total vertebrae 43—46 S. pelicanus 
3b Blind side of body without pepper-dot pattern of melanophores; dorsal-fin rays usually greater 
than 85; anal-fin rays usually greater than 69; usually more than 70 scales in longitudinal 
series; dorsal-fin origin in more anterior position, usually at point between verticals through 
middle of pupil and anterior margin of upper eye; dorsal and anal fins either uniformly pig- 
mented, or with series of alternating pigmented blotches and unpigmented regions, or with 
stripe along basal margin of fin; total vertebrae usually greater than 46 4 
4a Dorsal-fin rays 93-104; anal-fin rays 80-89; ocular-surface usually with a large, dark brown dia- 
mond-shaped blotch on caudal region of body (see Fig. 32), but otherwise uniformly pigmented and 
without pattern of distinct crossbands; basal margins of dorsal and anal fins with dark brown 
stripe, but without blotches; total vertebrae 51-56, usually 52-54 S. marginatus 
4b Dorsal-fin rays usually less than 95; anal-fin rays usually 84 or fewer; ocular-surface of body 
without dark brown, diamond-shaped blotch on caudal region, with or without distinct pattern 
of crossbands; dorsal and anal fins with or without pigmented blotches; total vertebrae 
47-53, usually 52 or less 
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