Munroe: Western Atlantic tonguefishes of the Symphurus plagusia complex 



279 



S. chabanaudi. Symphurus oculellus differs from S. 

 chabanaudi, however, in lacking the 4-8 small but well- 

 developed scales on the blind sides of the dorsal and 

 anal fin rays prominent in S. chabanaudi specimens, 

 especially those larger than 60 mm; in having a some- 

 what smaller eye (1.2-1.9, x 1.5 SL in S. oculellus vs. 

 1.7-2.3, x 1.9 SL), and S. oculellus has a well-devel- 

 oped fleshy ridge on the ocular-side lower jaw (absent 

 inS. chabanaudi). The posterior extension of the jaws 

 in S. oculellus extends to the vertical line through the 

 posterior margin of the eye, and in many specimens 

 the jaws actually extend slightly beyond the posterior 

 margin of the eyes, whereas in S. chabanaudi the 

 posterior extension of the jaws reaches only to a ver- 

 tical line through the rear margin of the pupil or the 

 rear margin of the lower eye. Symphurus oculellus also 

 differs from S. chabanaudi in the relative frequencies 

 of specimens possessing 1-5-3 and 1-4-3 ID patterns. 

 Symphurus chabanaudi has a much higher frequency 

 of occurrence of the 1-5-3 ID pattern (50% of indivi- 

 duals examined) compared with only 30% with a 1-4-3 

 pattern. In contrast, 40 of 45 (89%) of the S. oculellus 

 examined had a 1-4-3 pattern and only one specimen 

 possessed a 1-5-3 pattern. 



Symphurus chabanaudi also differs from S. oculel- 

 lus in that this species generally has about nine wide, 

 dark-brown crossbands compared with the more nu- 

 merous (10-14, usually 10-12), narrower bands in S. 

 oculellus. In addition, in S. oculellus the posterior two- 

 thirds of the dorsal and anal fins usually have an alter- 

 nating series of blotches and unpigmented areas, 

 whereas in S. chabanaudi the posterior one-third of the 

 dorsal and anal fins, and the caudal fin, are usually 

 uniformly dark-brown or black without alternating 

 blotches and unpigmented areas. 



There is almost complete overlap in fin-ray and ver- 

 tebral counts between those of 5. oculellus and those 

 of S. elongatus; however, these species are otherwise 

 distinct. Symphurus oculellus has prominent 

 crossbands on the body and a dark blotch on the ocular- 

 side opercle, whereas in S. elongatus the body is uni- 

 formly pigmented without crossbands, and a prominent 

 blotch on the ocular-side opercle is wanting. 



The remaining five eastern Pacific species with 

 meristics comparable to those observed in S. oculellus 

 include S. leei, S. atrico.udus, S. melanurus, S. william- 

 si, and S. undecimplerus. These species, in contrast to 

 S. oculellus, possess a pupillary operculum, and none 

 features the pigmented blotch found on the ocular-side 

 opercle in S. oculellus. Symphurus oculellus differs fur- 

 ther from S. undecimplerus in caudal-fin-ray number 

 (12 vs. 11); is distinguished from S. melanurus and S. 

 williamsi in having the dorsal and anal fins with an 

 alternating series of pigmented blotches and unpig- 

 mented areas (versus dorsal and anal fins without an 



alternating series of pigmented blotches and unpig- 

 mented areas in these other species); is readily distin- 

 guished from S. leei in having an unpigmented peri- 

 toneum (versus black in S. leei) and in having the head 

 length smaller than body depth (nearly equal to body 

 depth in 5. leei); and differs from S. atricaudus in lack- 

 ing the small ctenoid scales on the ocular-side dorsal 

 and anal fin rays characteristic of that species. 



Material examined 69 specimens (75.8-189 mm SL). 



Counted and measured (14 specimens, 75.8-164 mm SL). 

 Holotype: USNM 159606; female, 144 mm SL; Surinam (6°24'N, 

 55°00'W); 27m; 11 May 1957. Paratypes. Guyana: BMNH 

 1950.5.15: 51; (139); off Georgetown. FMNH 86365; (148); 7°05'N, 

 57°12'W; 33m; 1 Sep 1958. FMNH 88846; (132); 6°54'N, 57°47'W; 

 18m; 25 Mar 1963. Surinam: USNM 159559; (75.8); 6°04'N, 

 54°51'W; 70m; 13 May 1951. ZMA 111.212; (158); 5°15'N, 55°15'W; 

 12m; 13 Oct 1969. French Guiana: UMML 12254; (141); 6°17'N, 

 53°35'W; 40m; 21 Feb 1963. USNM 313518; 2(143-151); 6°12'N, 

 53°23'W; 46m; 1 Jul 1972. UMML 11549; (156); 5°57'N, 52°18'W; 

 70m; 22 Feb 1963. UMML 12262; (148); 5°24'N, 51°34'W; 64m; 

 23 Feb 1963. ZMA 111.234; (140); 3°45'N, 51°45'W; 40m; 16 Nov 

 1969. Brazil: FMNH 86362; (155); 1°57'N, 48° 15'W; 48m; 17 Nov 

 1957. FMNH 100385; (164); 1°57'N, 48°12'W; 55m; 14 Nov 1957. 



Counted (30 paratypes, 14 lots). Guyana: BMNH 1961.9.4:117 

 (189). BMNH 1961.9.4:118; (163). UMML 34335; (136); 7°42'N 

 57°32'W; 27m; 15 Jul 1968. Surinam: GCRL 3836; 5(130-165) 

 6°56'N, 54°05'W; 2 May 1969. UMML 12249; (143); 6°18'N 

 55°11'W; 18m; 20 Feb 1963. ZMA 111.228; 1; 5°15'N, 55°15'W 

 12 m; 10 Oct 1969. FMNH 90552; 2(142-147); Surinam; 18 m; 1957 

 FMNH 90553; (144); Surinam; 110m; 3 May 1957. FMNH 91368 

 (141); Surinam; 1957. French Guiana: FMNH 100386; 7(154-180): 

 6°03'N, 52°22'W; 65 m; 13 Sep 1958. FMNH 90085; 5(163-180) 

 5°46'N, 52°02'W; 70m; 12 Nov 1957. FMNH 86397; (130); 5°05'N 

 52°14.5'W; 20m; 23 May 1957. Brazil: FMNH 100387; 2(140-155); 

 2°29'N, 48°54'W; 86m; 15 Nov 1957. USNM 159541; (150); 2°29'N, 

 48°55'W; 42m; 15 Nov 1957. 



Other non-type material examined (25 specimens, 14 lots). 

 Guyana: UMML 34364; (152); 7°00'N, 57°08'W; 26m; 15 Jul 1968. 

 Surinam: UMML 12498; (158); 7°01'N. 54°21'W; 64m; 21 Feb 1963. 

 FMNH 90223; (135); 6°54'N, 54°47'W; 18m; 25 Mar 1953. UMML 

 34334; 2(104-140); 6°25'N, 55°04'W; 7 m; 10 Jul 1968. FMNH 

 91109; (151); 6°24.5'N, 55°02.5'W; 27m; 11 May 1957. USNM 

 159602; 2(82.2-94.8); 6°23'N, 55°05.5'W; 27 m; 11 May 1957. 

 USNM 313515; 3(136-152); 6°21'N, 54°28'W; 28m; 29 Jun 1972. 

 UMML 12310; 3(139-142); 6°11'N, 55°39'W; 15m; 19 Feb 1963. 

 French Guiana: UMML 13301; 6(111-175); 6°00'N, 52°27'W; 64m; 

 22 Feb 1963. UMML 13307; (166); 5°29'N, 51°37'W; 64m; 23 Feb 

 1963. UF 83997; (143); 5°05'N, 51°58'W; 45m; 11 Dec 1977. 

 USNM 313516; (147); 4°47'N, 51°37'W; 33m; 5 May 1975. UMML 

 34336; (160); off Cayenne; F. Berry, Station 10, 12. Brazil: UMML 

 12265; (150); 2°20'S, 40°24'W; 40m; 12 Mar 1963. 



