FISHERY BULLETIN: VOL. 81. NO. 2 



probably exhibits a positively allometric relation- 

 ship. 



HED shows an allometric growth relationship with 

 SL. Both HED and SL were log-transformed to fit the 

 linear regression of these two morphometric 

 variables (Fig. 5). HED are variable for a given size 

 interval; at 23 mm SL they vary between 1.60 and 

 1.86 mm, and at 29 mm SL between 1.72 and 2.00 

 mm (Fig. 5). Most of the variability occurs between 

 19 and 3 1 mm SL, after the transformation from flex- 

 ion to postflexion larvae. Very little variation occurs 

 in the preflexion and flexion stages (6-18 mm SL). 



SNTL appears to exhibit allometric growth with 

 respect to SL (Fig. 6). Both SNTL and SL were log- 

 transformed to fit a linear relationship between these 

 two variables. Snout lengths are variable for a given 

 size range in the postflexion stage, while very little 

 variation occurs within individual size ranges be- 

 tween 6 and 18 mm SL (Fig. 6). 



BD exhibits allometric growth with respect to SL 

 (Fig. 7). Increases in BD indicate corresponding in- 

 creases in body weight and body volume. As the SL 

 and BD increase, the body shape becomes more 

 streamlined, changing from a thin rodlike shape to a 

 deep-bodied, streamlined shape in A sapidissima. 



Myomeres 



Myomere counts have been shown to be useful for 

 identifying clupeoid genera (Ahlstrom 1968; Houde 

 et al. 1974). The total number of myomeres ranged 

 from 54 to 58; most of the larvae had 55 or 56 

 myomeres. The number and distribution of myo- 

 meres relative to body morphology are shown in Ta- 

 ble 2. 



The distribution of myomeres was examined in rela- 

 tion to predorsal and preanal body measurements. 

 Predorsal myomeres decreased in number with in- 

 creasing SL. Predorsal myomere counts decreased 



TABLE 2. — Distribution of myomeres relative to other body mor- 

 phology for Alosa sapidissima larvae. N = Number of specimens 

 counted; x = Mean myomere counts; R = Range of myomere 

 counts. 



E 

 o 



— 2 



E 



1 1 



« ! 



.8 

 6- 

 .4- 

 .2- 

 .0- 

 8- 

 .6 

 .4 

 .2- 

 .0- 

 8- 

 .6- 

 .4. 



N\ 



•' ' 



"I— 



2 



- 1 — 

 10 



- 1 — 

 14 



- 1 — 

 18 



— i — 

 22 



26 



— i 

 30 



Notochord - Standard Length (mm) 



FIGURE 5.— Scatterplot of HED/SL for larval Alosa sapidissima. Regression equation: 

 In (HED) = In 0.01 + 1.59 ln(SL):H = 0.973. 



328 



