FISHERY BULLETIN: VOL. 81, NO. 2 



lustrations. Those in the second series were cleared 

 and counterstained by the method used by 

 Dingerkus and Uhler (1977) for meristic and caudal 

 osteology studies. Selected specimens in the first 

 series were subsequently used for staining in the sec- 

 ond series, after measurements, pigment patterns, 

 and illustrations were completed. Field specimens of 

 A. sapidissima were also examined by the coun- 

 terstaining technique. 



Morphometries were taken by using an ocular mi- 

 crometer, calibrated to the nearest 0.1 mm, in a dis- 

 secting microscope and a dial caliper, calibrated to 

 the nearest 0.1 mm. Measurements follow closely 

 those of Houde et al. (1974) and are described as 

 follows: 



Total Length (TL): Tip of snout to end of caudal 

 finfoid complex in yolk sac and preflexion larvae, 

 and to end of the longest superior procurrent 

 caudal ray in flexion and postflexion larvae. 



Notochord- Standard Length (SL): Tip of snout to 

 tip of notochord in yolk sac, preflexion, and early 

 flexion larvae; tip of snout to base of hypural plate 

 in flexion and late flexion larvae; and tip of snout 

 to the point midway between the tenth superior 

 procurrent caudal ray and the first inferior caudal 

 ray in postflexion larvae and juveniles. Unless 

 otherwise noted in the text, all references to 

 lengths of larvae refer to standard lengths. The 

 use of this criteria for standard length measure- 

 ments is based on that set forth by Richards et 

 al. (1974). 



Preanal Length (PAL): Tip of snout to end of anus 

 measured along the midline of the body. This 

 measurement is also used to describe the location 

 of the anal fin for specimens that have shown 

 development of the anal fin complex. 



Predorsal Length (PDL): Tip of snout to break in 

 finfoid for specimens in yolk sac or very early pre- 

 flexion stage of development; tip of snout to origin 

 of first dorsal ray measured along the midline of 

 the body for fish exhibiting dorsal fin develop- 

 ment. If dorsal rays were not evident, then 

 measurement was made at the origin of the first 

 dorsal radial bone. 



Head Length (HL) : Tip of snout to posterior margin 

 of auditory vesicle in yolk sac and early preflexion 

 larvae; tip of snout to posterior margin of oper- 

 cular membrane and bone when development 

 was evident. 



Eye Diameter (HED): Horizontal diameter between 

 anterior and posterior edges of the fleshy orbit. 



Snout Length (SNTL): Tip of snout to anterior 

 margin of fleshy orbit on the eye. 



Body Depth (BD): Vertical height of the body mea- 

 sured at origin of the first dorsal ray. 



All morphometries were taken on the left side of the 

 fish body. Damaged specimens were not used; doubt- 

 ful measurements were eliminated from the study. 

 Meristics were taken from cleared and coun- 

 terstained flexion and postflexion specimens per the 

 methods of Berry and Richards (1973). 



RESULTS 

 Morphology of Larvae 



Morphometries for larval A. sapidissima are pre- 

 sented in Table 1. Alosa sapidissima body propor- 

 tions change during ontogeny with the most abrupt 

 changes occurring between 12 and 18 mm SL. HL, 

 SNTL, HED, and BD all exhibit curvilinear growth 

 with increasing SL. PAL and PDL exhibit linear 

 growth with increasing SL. 



SL was used to examine development of A. 

 sapidissima with respect to the other morphometric 

 data. Inspection of Figure 1 and a high coefficient of 

 determination (r 2 = 0.998) indicate a strong linear 

 relationship. SL length fluctuated between 97.5 and 

 92.4% of the TL for larvae measured. There were no 

 changes in the TL and SL relationship between 8 and 

 13 mm, where it remained at 96%. Changes in this 

 relationship were seen in the early postflexion stage 

 of development, between 18 and 23 mm (Table 1), 

 when the SL decreased from 97.2 to 95.7%. The SL/ 

 TL ratio averaged 96.5% for larvae <15 mm and 

 95.5% for larvae 15-31 mm. The decrease in body 

 proportion for the SL/TL relationship is related to 

 caudal fin development, particularly notochord flex- 

 ure between 12 and 15 mm, along with development 

 of the first and second hypural plates. 



PAL exhibited a steady decrease from 95% for 8 

 mm larvae to 65.4% for 3 1 mm larvae. Examination of 

 Figure 2, along with a high coefficient of determina- 

 tion (r 2 = 0.969), also tends to indicate a linear 

 relationship. At 18 mm SL, where the PAL/SL ratio 

 is invariate, transformation occurs from the flexion to 

 postflexion stage. The major changes in this re- 

 lationship were seen between 23 and 27 mm TL (Ta- 

 ble 1). Over this TL range, the gut is shortened and 

 transformations to the postflexion stage became evi- 

 dent, which tends to account for the decrease in the 

 PAL and SL relationship. 



PDL decreased with increasing SL (Table 1). There 

 appear to be three distinct size intervals at which the 

 PDL decreases (Fig. 3). The dorsal fin migrates for- 

 ward as dorsal rays develop and SL increases. This 



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