70 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Stephanolepis Gill 1861 



After examination of thousands of specimens 

 of this genus from the western North Atlantic, we 

 were able to distinguish only two species' — S. 

 hispidus (Linnaeus) and S. setifer (Bennett) . The 

 name setifer was applied to specimens from Cuba 

 and Atlantic Colombia with a relatively low 

 number of fui rays (D. 27-28, A. 26-27) by Fraser- 

 Brunner (1940: p. 519). His reasons for applying 

 and restricting this name certainly appear to be 

 justified. Stephanolepis setifer is identical with 

 Monacanthus oppositus Poey described by Meek 

 and Hildebrand (1928: p. 798) from Panama, but 

 we can not confu-m their species range of from 

 Massachusetts to BrazU. 



Five species of Stephanolepis were identified 

 from the western Atlantic by Fraser-Brunner 

 (1940). S. setifer has low niunbers of fin rays, 

 whereas the other four species were reported to 

 have 30 or more dorsal and anal rays. S. insignis 

 Fraser-Brunner 1940 and S. varius (Ranzani) 

 1842 were recorded from Brazil. Our specimens 

 of Stephanolepis do not represent either of these 

 forms; their distinguishing characteristics are not 

 too convmcing; none has been recorded from the 

 western Atlantic with the exception of the type 

 material. The remaining two species reported by 

 Fraser-Brunner were S. hispidus (Linnaeus) 1758 

 and S. spilonotus (Cope) 1871. We record S. 

 spUonotus as a sjmonym of S. hispidus, because 

 we judge our specimens to represent a single 

 species with moderate variation m morphological 

 characters, and because we found a complete 

 overlap in every character that Fraser-Brunner 

 (1940: p. 523, 535) used to separate the two 

 nominal species. Certainly there is no difference 

 between populations of S. hispidus from the At- 

 lantic and from the Gulf of Mexico, as his obser- 

 vations suggest. The five specimens Fraser- 

 Brunner designated as S. spilonotus from Florida, 

 Mississippi, and Cuba in the Museum of Com- 

 parative Zoology cannot be located. 



In Stephanolepis the first dorsal spine has two 

 rows of large, ventrally dkected barbs on its 

 posterior margin. The number of barbs present 

 is difficult to count, because those near the 

 base of the spine abruptly decrease in size, 

 particularly in larger specimens; but the number 

 of these barbs has been used previously as a 



taxonomic character (Fraser-Brunner, 1940: p. 

 523) to separate S. hispidus with 6 or 7 strong 

 barbs from S. spilonotus with 12 or more small 

 barbs. We have determined two features that 

 invalidate this character: (1) the barbs become 

 relatively smaller as the fish increases in size, and 

 (2) the number of barbs increases with growth of 

 the fish. The following counts of barbs from one 

 side of the spine of S. hispidus illustrate this sec- 

 ond invalidating feature (standard length in milli- 

 meters and number of barbs in parentheses) : 

 8.4 (3), 8.9 (2), 9.5 (3), 16 (3), 16.5 (3), 16.5 (2), 

 17 (3), 17.5 (2), 18 (2), 20 (3), 24.5 (4), 26.5 (4), 

 29.5 (2), 42.5 (5), 44 (5), 48 (5), 52.5 (6), 59 (6), 

 62 (5), 66 (5), 67 (6), 70 (6), 72 (6), 72 (7), 73 (8), 

 81 (10), 83 (8), 97 (8), 114 (8), 122 (10), 136 (8), 

 139 (11), 142 (10), 143 (12), 145 (9), 151 (11), 158 

 (13), 167 (11). Frequently the number of barbs 

 on each side of the back of the spines varies by 

 1 or 2, and in these cases the count from the side 

 having the greater number of barbs was recorded. 



It is characteristic that a small percentage of 

 specimens of most of the species of Monacan- 

 thidae examined had a background pigmentation 

 much darker than average. This was observed 

 in specimens preserved in both alcohol and for- 

 malin. Conversely, some few of the preserved 

 specimens were almost unpigmented. This caused 

 some difficulty in confirming pigmentation char- 

 acteristics for S. hispidus and S. setifer, but 

 usually when moist specimens were examined the 

 correct determination could be made (drying or 

 partly drying of specimens makes the pigmenta- 

 tion more difficult to see) . This feature produces 

 excessive difficulties in utilizing the key to the 

 species of Stephanolepis by Fraser-Brunner (1940: 

 p. 521), in which the primary couplet concerns 

 pigment (longitudinal pattern of bars, patches, 

 or bands vs. transverse and mottled pattern). 



The profile from snout to dorsal spine of S. 

 hispidus is concave in most specimens, but in 

 some it is nearly straight, and in others slightly 

 convex. 



The distance from the upper edge of the orbit 

 to the base of the first dorsal spine in S. hispidus 

 is also variable and may be either greater or less 

 tlian the diameter of the eye. 



We have found no specimens of Stephanolepis 

 setifer from the coast of the United States, where 

 S. hispidus is relatively common. Analysis of 



