THE CORRELATION BETWEEN NUMBERS OF VERTEBRAE 



AND LATERAL-LINE SCALES IN 

 WESTERN ATLANTIC LIZARDFISHES (SYNODONTIDAE)i 



William W. Anderson,^ Jack W. Gehringer,^ and Frederick H. Berry'' 



ABSTRACT 



The 10 species of Synodontidae in the western Atlantic have a positive correlation between 

 numbers of vertebrae and pored lateral-line scales. A ratio of close to 1:1 exists for all species, 

 with individuals having from four more to two fewer scales than vertebrae, and the majority 

 having at least one more scale than vertebrae. Geographic variation is suggested by vertebral 

 counts of four species, and possible taxonomic heterogeneity is indicated by the counts of a fifth 

 species. Scale counts are bilaterally symmetrical in most individuals and differ by one scale in 

 most of the rest. Vertebral and scale counts are given for type specimens at the U.S. National 

 Museum of Natural History. 



The principal purpose of this paper is to describe 

 the complements and correlations of vertebrae 

 and pored lateral-line scales in samples of the 

 western Atlantic species of Synodontidae, as a 

 contribution to the knowledge of their mor- 

 phology and to facilitate specific identification of 

 various life history stages. 



The species of the lizardfish family Syno- 

 dontidae have been distinguished in part by 

 differences in number of pored lateral-line scales 

 for juvenile and adult stages (e.g. Norman 1935; 

 Anderson et al. 1966a, b) and in number of myo- 

 meres for larval and prejuvenile stages (Gibbs 

 1959). Accurate scale counts may be impossible 

 in damaged or small specimens, and myomeres 

 are difficult to count in all but young stages. 

 Numbers of myomeres in individual fish are 

 equal or about equal to numbers of vertebrae, 

 but species complements of vertebrae in syno- 

 dontids have not been analyzed or utilized. 



For the 10 species of lizardfishes in the western 

 Atlantic, we have determined that: 



1) complements of vertebrae and intraspecif- 



'Contribution from the Georgia Department of Natural 

 Resources and Contribution No. 25 from the South Carolina 

 Marine Resources Center. 



^Georgia Department of Natural Resources, Brunswick, GA 

 31520. 



'National Marine Fisheries Service, Washington, DC 20235. 



"Marine Resources Research Institute, P.O. Box 12559, 

 Charleston, SC 29412; present address: Southeast Fisheries 

 Center, National Marine Fisheries Service, NOAA, Miami, FL 

 33149. 



ically variable with a relatively normal 

 distribution around the mean (as occurs 

 with complements of scales and myomeres); 



2) numbers of vertebrae have a positive cor- 

 relation to numbers of pored lateral-line 

 scales; 



3) in individuals, the number of vertebrae 

 is in a ratio of close to 1:1 to the number 

 of pored lateral-line scales, with scales 

 ranging from two less to four more than 

 vertebrae in our samples, and the majority 

 of specimens of all species having more 

 scales than vertebrae. 



MATERIALS AND METHODS 



Specimens used in this study are in the col- 

 lections of the Florida State Museum (formerly 

 in the Tropical Atlantic Biological Laboratory, 

 Miami, Fla. and the Biological Laboratory at 

 Brunswick, Ga.), the Academy of Natural Sciences 

 of Philadelphia, and the U.S. National Museum 

 of Natural History (USNM). Some of the speci- 

 mens used in these analyses were specifically 

 selected from material previously reported by us 

 (Anderson et al. 1966a) to encompass high 

 and low values in scale counts of the various 

 species or to obtain geographic coverage. 



Identifications, measurements, and counts 

 were made as described by Anderson et al. 

 (1966a) with the following additions: 



Vertebrae — counted from the anteriormost 

 centrum articulating with the occipitals to and 



Manuscript accepted May 1974 



FISHERY BULLETIN: VOL. 73, NO 1 1975 



202 



