POMPANOS OF SOUTH ATLANTIC COAST 



213 



70 mm. in all species, with T. carolinus, T.falcatus, 

 and T. glaucus maintaining pectoral lengths of 

 22-25%, 21-24%, and 21-22% S.L., respectively, 

 to about 210-220 mm. S.L. Above 230 mm., T. 

 carolinus continues a pectoral-length range of 

 22-25% S.L., with the largest specimen (341 mm.) 

 possessing a pectoral length of about 19% S.L. 



PELVIC FIN 

 Elements 



Trachinotus sp. — There is no evidence of the fin 

 at 3.07 and 4.0 mm., but at 4.66 mm. buds are 

 discernible (figs. 1-3). 



T. carolinus. — Elements I, 5. All soft-rays are 

 segmented but none are branched before 10-12 

 mm. Between 12 and 16 mm. various states of 

 branching are apparent, and after about 16 mm. 

 branching is complete. 



T. falcatus. — Elements I, 5. At 5.0 mm. the 

 pehnc fins are minute buds, arid by about 6.5 mm. 

 the fins are small, flattened, flipperlike structures 

 without spine or soft-rays. Spines and soft-rays 

 are discernible at about 7 to 7.5 mm. (one 7.3-mm. 

 specimen possesses a spine but no discernible soft- 

 rays, the other specimens have the fuU comple- 

 ment). Segmentation begins at about this size 

 and is completed by about 9.5 mm. Branching 

 commences at about 11-12 mm. and is completed 

 at 14-18 mm. 



T. glaucus. — Elements I, 5. At 7.8 mm. all 

 soft-rays are segmented, and branching is complete 

 by 11.8 mm. 



Lengths 



Relative pelvic-fin length increases very rapidly 

 in all species from about 5-11% S.L. at sizes 

 below 10 mm. to about 16-17% S.L. at about 

 20 mm. T. carolinus maintains a pelvic length of 

 about 15-19% S.L. to about 100 mm., after which 

 relative pelvic length decreases gradually, becom- 

 ing about 10% S.L. at sizes larger than about 

 290 mm. Relative pelvic length decreases gradu- 

 ally witli an increase in standard length in T. 

 falcatus at sizes above about 30 mm., becoming 

 about 11% S.L. in specimens larger than 170 mm. 

 T. glaucus maintains a pelvic length about 17% 

 S.L. to about 70 mm., after which there is a 

 gradual relative decrease with an increase in 

 standard length, becoming 13% S.L. in the 211- 

 mm. specimen (appendix table 2 and fig. 23). 



CAUDAL FIN 

 Elements 



Trachinotus sp. — At 3.07 and 4.0 mm. the caudal 

 raj-^s are not evident, but at 4.66 mm., si.\ principal 

 rays in each lobe are discernible (figs. 1-3). 



T. carolinus. Rays 9 4-8. All principal rays 

 are present and segmented, but none is branched 

 at 7.2 mm. The two median caudal rays branch 

 at about 10 mm., by about 11 mm. five or six 

 rays in the upper lobe and about five in the lower 

 lobe are branched, and branching is complete at 

 15-20 mm. 



T. falcatus. — Rays 94-8. By 5-7 mm. all prin- 

 cipal rays are present, and all but the outermost 

 principal ray in each lobe are segmented. Seg- 

 mentation is complete between 7 and 7.5 mm. 

 Branching begins with the median caudal rays 

 and is complete by about 12 mm. 



T. glaucus. — Rays 9-f-8. At 7.8 mm. all principal 

 rays are present and segmented, but none is branched. 

 At 11.8 mm. six rays in the upper lobe and five 

 in the lower are branched, and by 14.6 mm. 

 seven upper rays and six lower ones are branched. 

 All specimens larger than about 15 mm. exhibit 

 complete branching. 



Lengths 



Relative caudal-fin lobe length gradually in- 

 creases with an increase in standard length to 

 about 250 mm. in T. carolinus. Maximum rela- 

 tive length of this part is undetermined in T. 

 falcatus and T. glaucus since a continuing and 

 moderate increase was indicated by the largest 

 specimens examined. Below 10 mm. T. falcatus 

 and T. glaucus exhibit caudal-fin lobe lengths 

 about 25-35% and 33% S.L., respectively. At 

 10-30 mm., the lengths of this part for T. caro- 

 linus, T. falcatus, and T. glaucus are about 31- 

 34%, 31-38%, and 35% S.L., respectively. 

 Caudal-fin lobe length in T. caroliims increases to 

 about 41-44% S.L. at 230 to 260 mm.; thereafter, 

 the part decreases in relative length, approaching 

 35% S.L. at sizes larger than 300 mm. The 

 four largest T.falcatus (172-216.5 mm.) had caudal 

 lobe lengths 42.9-45.5%, and three of the larger 

 T. glaucus (124-141.5 mm.) had caudal lobe 

 lengths 42.8-47.3% S.L. (appendix table 2 and 

 fig. 22). 



GILL RAKERS 



The complete gill-raker complement in 

 Trachinotus is 7 or 8+ 13 or 14. This complement 



