274 



Fishery Bulletin 89(2). 1991 



Despite co-occurrence and some morphological sim- 

 ilarities, S. tessellatus is readily distinguished from 

 S. diomedeanus and S. jenynsi in caudal-fin-ray number 

 (12 in S. tessellatus vs. 10 in the others), and presence 

 of scales on the blind sides of the dorsal and anal fin 

 rays and presence of a black spot on the ocular-side 

 opercle (absent in the others). Symphurus tessellatus 

 differs further in lacking a pupillary operculum and the 

 large pigmented spots in the dorsal and anal fins 

 characteristic of S. diomedeanus. From S. jenynsi, S. 

 tessellatus is further distinguished by its much lower 

 meristic values, including 91-102 dorsal fin rays (vs. 

 107-115), 77-86 anal fin rays (vs. 91-99), and 49-54 

 total vertebrae (vs. 57-60 in S. jenynsi). 



There are nine eastern Pacific Symphurus with 

 somewhat similar ID patterns, comparable fin-ray 

 counts, or pigment patterns reminiscent of those 

 observed in S. tessellatus. Of these nine, only S. cha- 

 banaudi Mahadeva and Munroe and S. elongatus (Gun- 

 ther) are similar to S. tessellatus in that they lack a 

 pupillary operculum. Of all species in the genus, S. tes- 

 sellatus is most similar in form, size, and pigmentation 

 pattern to S. chabanaudi. However, <S. tessellatus is 

 distinguished from S. chabanaudi primarily by modal 

 differences in the number of dorsal (91-102 vs. 98-109 

 in S. chabanaudi) and anal fin rays (74-86 vs. 82-92); 

 total vertebrae (48-54, usually 50-53 vs. 52-57, usually 

 53-56); and scales in a longitudinal series (81-96 vs. 

 92-102 in S. chabanaudi). The two species also differ 

 in relative frequencies of occurrence of particular ID 

 patterns. In S. chabanaudi, 50% (49/95) of the in- 

 dividuals had a 1-5-3 ID pattern while only 30% (28 

 specimens) featured a 1-4-3 pattern. In contrast, 173 

 of 233 (74%) S. tessellatus possessed a 1-4-3 ID pattern, 

 while only 6% (13 specimens) had a 1-5-3 pattern. 



There is some overlap in fin-ray and vertebral counts 

 between S. tessellatus and S. elongatus; however, these 

 overlaps are the only similarities between these other- 

 wise distinctive species. Symphurus tessellatus has a 

 pattern of crossbands on the body and a large black 

 blotch on the ocular-side opercle, whereas in S. elonga- 

 tus the body is uniformly pigmented without cross- 

 bands and this species lacks the prominent black blotch 

 on the ocular-side opercle. Further differences include 

 the presence of small ctenoid scales on blind sides of 

 the dorsal and anal fin rays in S. tessellatus (absent in 

 S. elongatus) and absence of a fleshy ridge on the 

 ocular-side lower jaw in S. tessellatus (a well-developed 

 ridge present in S. elongatus). Symphurus tessellatus 

 also has a much larger eye (15-21 SL) compared with 

 that of S. elongatus (9-15 SL). 



The remaining seven eastern Pacific species with 

 meristics comparable to those observed in S. tessella- 

 tus include S. fasciolaris, S. leei, S. atricaudus, S. 

 melanurus, S. williamsi, S. melasmatotheca, and S. 



undecimplerus Munroe and Nizinski. As mentioned 

 above, all of these species, in contrast to S. tessellatus, 

 possess a pupillary operculum, and none have the black 

 spot on the ocular-side opercle characteristic of S. tes- 

 sellatus. Symphurus tessellatus differs further in 

 caudal-fin-ray number (12) from S. fasciolaris (10) and 

 S. melasmatotheca and S. undecimplerus (each with 1 1 

 caudal fin rays). Symphurus tessellatus is distinguished 

 from S. melanurus in lacking a fleshy ridge on the 

 ocular-side lower jaw (present in S. melanurus), in hav- 

 ing small ctenoid scales on the blind sides of the dorsal 

 and anal fin rays (usually none or occasionally 1-3 small 

 scales at bases of fin rays in S. melanurus), and in 

 having the first dorsal fin ray placed posterior to a 

 vertical through the front margin of the upper eye 

 (versus first dorsal fin ray placed anteriorly to a ver- 

 tical through front margin of upper eye in S. mela- 

 nurus). Symphurus tessellatus is further distinguished 

 from S. williamsi in having crossbanding on the body 

 with the posterior portions of the dorsal and anal fins 

 considerably darker than the anterior portions (versus 

 uniform body color without prominent crossbanding 

 and no posterior darkening of dorsal and anal fins in 

 S. williamsi). Symphurus tessellatus differs from S. 

 leei in having an unpigmented peritoneum (versus black 

 in S. leei), and the length of the head is smaller than 

 the body depth in S. tessellatus (nearly equal to body 

 depth in S. leei). Symphurus tessellatus is further 

 distinguished from S. atricaudus in that it lacks the 

 small ctenoid scales on the ocular-side dorsal and anal 

 fin rays characteristic of that species. 



Material examined 454 specimens (13.4-220 mm 

 SL). 



Counted and measured (23 specimens, 96.6-203 mm SL). Puerto 

 Rico: UPRM 2717; (142); Puerto Rico; 8m; 14 Mar 1966. UPRM 

 2760; (142); Mayaguez; 12m; 15 Mar 1966. UPRM 2859; (111); 

 Mayaguez; 9m; 29 Apr 1966. UPRM 3758; (130); Anasco River; 1-2 

 Jul 1953. UPRM 3759; 2 (130-133); Mayaguez Bay; 1966. French 

 Guiana: UF 35275; (172); 5°14'N, 52°06'W; 45m; 11 Dec 1977. 

 Brazil: UFPB 143; 5(96.6-135); Rio Paraiba do Norte; 27 Apr 1978. 

 MHNN 691; (140.3); Bahia (possible holotype or syntype oiPlagusia 

 brasiliensis). ANSP 121549; 10(108-203); Rio de Janeiro; Jul-Aug 

 1963. 



Counted (234 specimens, 64 lots). Puerto Rico: MCZ 28843; 

 (91.8); Puerto Rico; 1898-99. UF 83996; (146); beach at Mani. just 

 N of Mayaguez; 16 Apr 1964. UPRM 1590; 2(159-173); Mayaguez; 

 3 Mar 1962. UPRM 2743; 15(114-172); Mayaguez; 6m; 15 Mar 

 1966. UPRM 3760; 2(128-143); Rio Anasco; 17 Aug 1951. UPRM 

 3761; 3(126-158); Mayaguez Bay; 1966. USNM 126448; (132); Maya- 

 guez; 1899. Cuba: MCZ 11269; (111); Cuba. USNM 35108; (81.3): 

 Havana. USNM 37750; (68.6); Havana. USNM 154857; (131) 

 Cuba. Dominican Republic: USNM 108369; (123). USNM 108372 

 (126). Haiti: ANSP 81861; (97.7); Port-au-Prince; Nov 1949. ANSP 

 83626; 8(83.3-113); Port-au-Prince; 1949. ANSP 97661; 6(114-146); 

 Port-au-Prince; 1936. UMMZ 142422; (127); Haiti; 15 Apr 

 1983. USNM 133671; 3(109-124); Port-au-Prince; 1-4 Jan 1947. 

 USNM 164849; 2(87.7-133); Haiti; 1927. Jamaica: LACM 6215; 

 (142); 17°52'N, 77°53'W; 40m; 15 May 1962. LACM 6217; 10(123- 



