418 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



northern Bahamas, into the North Atlantic Cur- 

 rent east of the Grand Banks. If such is the case, 

 spawning might be expected to occur along all but 

 the more northern portions of the route, and the 

 young forms might be expected to follow or be 

 moved by the drift of the Gulf Stream and the 

 currents contributing to the Stream until a critical 

 stage, at which time they would act against the 

 effects of the stream. 



The purposes of the present work are to ex- 

 pand the known definitions and variability of the 

 morphological, morphometric, and meristic char- 

 acters of Caranx species off the Atlantic coast of 

 the United States, principally the five common 

 species, to facilitate their identification and to 

 furnish a basis for comparison with the poorly 

 known relationships of closely related species or 

 forms from other geographic areas; to provide a set 

 of serial illustrations to depict the changes from 

 the smallest larval forms available into the better- 

 known juvenile stages; to depict growth relation- 

 ships for selected body parts; and to discuss dis- 

 tribution and theories of time and place of repro- 

 duction in waters off the southeastern United 

 States. 



I am grateful to Isaac Ginsburg and Elbert 

 H. Ahlstrom of the U. S. Fish and Wildlife Service 

 for their critical review of the manuscript and to 

 John C. Briggs and Arnold B. Grobman of 

 the University of Florida for their propitious 

 suggestions. The loan or procurement of speci- 

 mens and information on specimens by the follow- 

 ing were instrumental in the study: Leonard 

 P. Schultz, U. S. National Museum; John C. 

 Briggs, University of Florida Museum; James 

 E. Bohlke, Academy of Natural Sciences of Phila- 

 delphia and Chaplin Bahaman Shore Fish Pro- 

 gram; E. Milby Burton, Charleston Museum; 

 James E. Morrow, Bingham Oceanographic 

 Collection; Myvanwy M. Dick, Museum of 

 Comparative Zoology; G. Robert Lunz, Bears 

 Bluff Laboratories; John T. Nichols, American 

 Museum of Natural History; Harvey R. Bullis, 

 Jr., Edgar L. Arnold, Jr., Fred C. June, David K. 

 Caldwell, Doyle Sutherland, and Melba Wilson, 

 U. S. Fish and Wildlife Service; E. Lowe 

 Pierce and Benjamin B. Leavitt, University of 

 Florida; G. Palmer, British Museum (Natural 

 History); David H. Gould, Robert H. Godley, 

 J. A. Jones, and William F. Ricks, Georgia Game 

 and Fish Commission; Edwin H. Chandler, Lewis 



Crab Co., Brunswick, Ga.; and J. B. Siebenaler 

 and Winfield Brady, Gulfarium, Fort Walton 

 Beach, Fla. The assistance and suggestions of 

 members of the staff of the South Atlantic Fishery 

 Investigations were most helpful in preparation 

 of the manuscript. 



METHODS 



COUNTS 



Meristic counts on fish of less than about 200 

 mm. standard length were made under magnifica- 

 tion. Aberrant counts, such as occur on injured 

 specimens, were either omitted or specifically 

 described. 



MEASUREMENTS 



All measurements of fish of less than about 45 

 mm. standard length were made with a calibrated 

 micrometer eyepiece and a stereoscopic micro- 

 scope, as were smaller structures on fish above this 

 size. Other measurements were made with a pair 

 of fine-point dividers. Measurements of pre- 

 opercular spues were recorded to the nearest one- 

 one hundredth millimeter. All other measure- 

 ments were recorded as follows: Up to 45 mm. 

 standard length, to the nearest one-tenth milli- 

 meter; 45 to 100 mm. standard length, to the near- 

 est one-half millimeter; over 100 mm. standard 

 length, to the nearest millimeter — with the excep- 

 tion of the standard lengths of fish not included in 

 the graphs, which were measured to the nearest 

 one-half millimeter if smaller than 100 mm., and 

 to the nearest millimeter if larger. 



The figures and tables in this report do not in- 

 clude data on the relation of the lengths of the 

 fourth dorsal spine, the second dorsal soft-ray, 

 pelvic, fin, and body depth at first anal spine to 

 standard length; or measurements of the first and 

 second anal soft-rays. 



CONSTRUCTION AND INTERPRETATION OF 

 GRAPHS 



Graphs of the relation of the mean number of 

 scutes, of the mean lateral-line ratio, and of the 

 preopercular-angle spine length to standard length 

 for the individual species have been fitted with 

 visually estimated perimeters enclosing the dots 

 or other described marks that represent coordi- 

 nates of the individual specimens. The graphical 

 area enclosed by each perimeter is intended to 

 depict the range of variation for that relationship. 



