FISHERY BULLETIN: VOL. 82, NO. 1 



TaBI I 6. Meristics in gulf menhaden, Hrcvtmrtia patronus, (35 specimens) and in Atlantic menhaden, li 



tyrannus, (3 I specimens). 



including the hypural bones, was 45.3 counted in 21 

 specimens longer than 16 mm SL. The first bones to 

 stain with alizarin red S were the dentaries, the max- 

 illaries, and the cleithra which occurred in 9 mm 

 specimens. 



Only vertebrae and ventral scute counts were useful 

 in separating gulf menhaden and Atlantic menhaden; 

 other meristics overlapped (Table 6). Yellowfin 

 menhaden larvae could not be separated from the 

 two large-scaled menhaden by meristics, with the 

 possible exception of Atlantic menhaden that had 

 47-48 vertebrae and yellowfin menhaden that had 

 45-47 (including the hypural bones) (Dahlberg 1970). 



Pigmentation 



Pigmentation of gulf menhaden larvae (Figs. 1,3,5, 

 6) was similar, but not identical, to the pigmentation 



described for yellowfin menhaden (Houde and Swan- 

 son 1975) and Atlantic menhaden (Jones etal. 1978). 

 Gulf menhaden up to 8 mm had 1 melanophore on the 

 dorsal side of the notochord tip and 1 or 2 mela- 

 nophores on the ventral side of the notochord tip, 

 which is diagnostic for the genus Rrevoortia (Figs. 1C, 

 D, 5A). Lateral pigmentation, although found on the 

 trunk of specimens as small as 4.9 mm, was not found 

 on all small specimens. At 10 mm, all specimens had 

 5-20 melanophores scattered the length of the trunk. 

 Larvae 4-5 mm had 10-20 tiny melanophores on top 

 of the head. One 7.8 mm larva had a single stellate 

 melanophore on top of the head behind the eyes. One 

 single medial melanophore, which enlarged into 

 additional melanophores as larvae grew, was present 

 along the isthmus (ventral midline forward of the 

 cleithrum) on 6 mm and larger larvae. On 8-20 mm 

 larvae, 1 or more melanophores occurred along the 



Vrftl 



1mm 



Fit, i RE 5. Larval Brei oortla patronus: (A) 7.2 mm (12 d alter hatching). (B) 9.2 mm (20 d after hatching). 



92 



