BADCOCK and BAIRD: SYSTEM ATICS OF STERNOPTYX 





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Figure 3.— S^emopfyi diaphana, 32 mm SL. 



S diaphana^ 



S pseudobscura^ 



S obscura^ 



S pseudodiaphana' 



S pseudodiaphana^ 



S pseudodiaphana*' 



12 

 19 

 2 

 4 

 3 



40 

 20 



53 



5 



21 



7 

 4 

 5 



11 



— 3 

 4 — 



39 

 18 



68 



3 — 

 34 3 



4 3 

 11 — 



^Atlantic and Pacific populations represented 



^Atlantic and central Pacific populations represented 



^East Pacific populations only 



^Northeastern and southern Atlantic and southeastern Pacific populations represented 



^Tropical Atlantic subset (included in 4) 



^Southeastern Pacific subset (included in 4) 



diaphana (>18 mm SL) can be distinguished on 

 the basis of vertebral number 29-32 versus 27-29, 

 respectively, Table 2; see also Borodulina 1978), 

 and the placement of the photophore SAN (de- 

 scribed by SAN depth/SL and trunk depth/SAN 

 height, Figures 6, 7) which is appreciably raised in 

 S. pseudodiaphana . Overlap of more than one of 

 these three characters in any given specimen was 



rarely observed. Other differences, most notice- 

 able in sympatric populations, occur in body shape 

 and pigmentation. Sternoptyx diaphana is gener- 

 ally deeper in body and especially trunk, appreci- 

 ably less pigmented, and lacks streaks on the 

 outer ventral caudal fin margin in larger indi- 

 viduals (Tables 3, 4). 



Sternoptyx obscura is distinguished from S. 



807 



