368 Memoir Sears Foundation for Marine Research 



the auxiliary spots usually appearing later. Fins mostly plain yellowish green; the 

 caudal with a dusky margin. Peritoneum jet black. 



Size. A small size seems to be normal. An example 265 mm (10.6 in.) TL is 

 the largest now at hand. Goode {^44) quoted Silas Stearns as having seen examples 1 1, 

 12, and 13 inches long, but these may have been gunteri. 



Development and Growth. The postlarvae, 19— 24 mm TL and 16— 19 mm SL, 

 are relatively slender, though deeper than young of tyrannus of the same length, their 

 greatest depth being about 7.4-10.5 in TL and 4.75-8.0 in SL. Also, these young 

 fish are more advanced in development, for even the smallest ones have all fins (ex- 

 clusive of the pectoral) well enough developed to show rays; however, the pelvic 

 fin is still well in advance of the dorsal. The convoluted intestine, characteristic of 

 young clupeoids generally, remains evident in the smaller examples but has become 

 fully invaginated in the larger ones. The snout seems to be rather more pointed in 

 the postlarvae than in larger fish, and the large rounded maxillary scarcely reaches 

 beyond the anterior margin of the pupil. The gill rakers of the upper limb do not 

 yet extend down and over those of the lower limb, and the filaments on the pos- 

 terior rim of the gill arches are little developed at this size. The ventral scutes in 

 front of the pelvics are well developed in the largest specimens, but not those behind 

 them. The smallest specimens have a series of dark chromatophores along the lateral 

 edge of the abdomen and another along the anal base; also, few dark chromatophores 

 are present on the opercle, on the base of caudal, and on the chest; some of these 

 markings have become obscure in the larger specimens of this lot. Dark specks, 

 present on the caudal and dorsal fins, are decidedly more numerous in the larger 

 specimens than in the smaller ones. 



Specimens of about 30 mm already are shaped much like adults. Scales in part 

 are developed, and general pigmentation has taken place, the lower part of the sides 

 already being silvery in some specimens. The dark specks on the dorsal and caudal 

 fins have increased greatly in number, but the chromatophores along the base of anal 

 of juveniles remain faintly visible. The gill rakers have increased considerably in pro- 

 portionate length, and those of the upper limb now extend downward across those of 

 the lower limb; the filaments, too, are much better developed. The maxillary remains 

 shorter than in adults, for it scarcely reaches below the middle of the eye. Striations are 

 faintly visible on the upper part of the opercle, the ventral scutes are fully developed, 

 and the pelvic fin now is situated under the anterior rays of the dorsal, as in adults. 

 The dark peritoneum is plainly visible through the abdominal walls at this stage of 

 development. 



Little is known about the rate of growth. Length frequencies, based on 186 fish, 

 suggest that a maximum length of about 100 mm (4 in.) is attained at one year of age, 

 probably 1 50 mm (6 in.) at two years. However, some of the fish in each year-class are 

 much smaller, some being only about 80 mm long at one year of age and about 125 mm 

 at two years. The rate of growth seems to be about the same as that of tyrannus at 

 Beaufort, North Carolina. 



