Table 6. Body Proportions for 12 Specimens each of Benthosema panamense (from 

 THE Eastern Pacific Ocean) and B. pterotum (from the Northern Indian 

 Ocean) 



B. panamense 



Measurement 



SL— 34. 1-49.6 mm 



Ave. 



Range 



B. pterotum 



SL— 32.1-41.5 mm 



Ave. 



Range 



Head length 

 Head depth 

 Orbit length 

 Upper jaw length 

 Prepectoral length 

 Prepelvic length 

 Predorsal length 

 Preanal length 

 Preadipose length 

 Dorsal origin to pelvic origin 

 Dorsal origin to anal origin 

 Caudal peduncle length 

 Caudal peduncle depth 

 Dorsal base length 

 Anal base length 

 Pectoral fin length 



Taning ( 1932) indicated that B. panamense had about two more anal fin rays than did B. 

 pterotum (citing Norman (1929, p. 513) as authority); but it is possible that Norman had 

 confused B. fibulatum with B. pterotum ; the number of anal rays are 19 (18-20) in the B. 

 fibulatum before me. It is also possible that B. pterotum from throughout the Indian Ocean is 

 highly variable in this regard, for the counts given in Table 7 do not support the difference 

 stated by Taning. 



The numbers of dorsal rays, AO photophores ( AOa, AOp, and total), and vertebrae of S. 

 panamense and B. pterotum overlap almost completely; the respective counts are as follows 

 (those for B. panamense given first); dorsal rays 13(12-14), 13 (12); AOa 6 (5-7) + 4 (3) for both 

 species, total 10 (9-11), 10 (9); vertebrae 32 (31) for both species. 



Thus, the two species are very much alike in counts and proportions. It may be that a 

 study of abundant material of B. pterotum from throughout its presumed range (the Indo- 



Table 7. Numbers of Anal and Pectoral Fin Rays and Total Gill Rakers for Bentho- 

 sema PANAMENSE -FROM THE EASTERN PACIFIC OCEAN AND FOR B. PTEROTUM FROM 



THE Northern Indian Ocean 



Pectoral rays 



12 



13 



14 



15 



B. panamense 

 B. pterotum 



8 

 15 



22 

 9 



Total gill rakers 



25 



B. panamense 

 B. pterotum 



26 



4 

 19 



27 



22 

 9 



28 



57 

 5 



29 



31 



2 



30 

 13 



31 



32 

 31 



128 

 42 



45 



