Fishes of the Western North Atlantic 351 



Development and Growth. The eggs and larvae have been described by Kuntz and 

 RadcHffe from material collected at Woods Hole, Massachusetts {^6 : 119). The eggs 

 are buoyant and spherical, have a diameter of 1.4-1.6 mm, and are highly transparent; 

 they contain a small oil globule, and are covered with a thin horny membrane; the 

 perivitelline space is broad. Incubation occupied "not more than 48 hours." 



The newly hatched fish are "relatively slender" and about 4.5 mm long. The 

 vent, as usual in clupeoid fishes, is "less than one-fifth the length of the body from the 

 posterior end." At four days of age the larvae were 5.7 mm long, and black chromato- 

 phores were present in a series along the entire digestive tract. At 9.0 mm the dorsal 

 and caudal fins were at least partly developed, and posteriorly the intestine was convo- 

 luted. At 23 mm all the fins had become well differentiated, and the body remained 

 "relatively slender"; black chromatophores were present on the nape, along the margin 

 of the opercle, near the base of the dorsal, anal, and caudal fins, and in groups posterior 

 to the dorsal fin and ventral to the pectoral fin; internal black areas could be seen 

 along the dorsal wall of the abdominal cavity, and a series of dark spots was present 

 above the notochord. 



Compared to the Woods Hole larvae, specimens from Beaufort, North Carolina, 

 of comparable size agree with them fairly well in development, but in each phase they 

 are notably more slender. Beaufort examples 9.0 mm long are little compressed and 

 scarcely thicker than a number-60 sewing thread; the depth is contained about 

 30 times in TL. Specimens 18 mm long are fully as well developed as those of 23 mm 

 described and illustrated by Kuntz and Radcliffe, and the 23-mm examples are rather 

 more advanced than the northern ones of equal length; the body continues to be more 

 slender; the depth is contained about 21 times in TL. In 25-mm preserved examples 

 from Beaufort, the convoluted intestine noted in younger fish is scarcely discernible, 

 and the vent Is now situated slightly behind a vertical from the base of the last dorsal 

 ray, about as in the adult. Some examples, at a length of 30 mm, or even up to '^1^ mm, 

 remain very slender, their depth being contained about 13 times in TL; and in these 

 slender examples the ventral surface of the chest and abdomen remains round to slightly 

 flat, with indications of a row of bony points along each lateral edge. Juvenile pigment 

 spots remain about as described for examples of 23 mm or so, but other specimens of 

 the same length are much more compressed and notably deeper; their greatest depth 

 is contained only about 7.7 times in TL, or only about 6.7 in SL. In these deeper 

 and older fish, the two series of lateral bony points noted in the slender fish have 

 become coalesced to form definite ventral scutes on the median line of the chest and ab- 

 domen ; also, the fish are rather fully pigmented, the sides of the head are bright silvery, 

 a silvery lateral band is evident, and a sheen of the same color is present on the sides of 

 the abdomen. It seems, then, that when the fish reach a length of about 30 mm the 

 increase in length is retarded during metamorphosis from the somewhat roundish 

 slender larvae to the deeper and more compressed young adults. 



Schools of young Atlantic Menhaden were observed repeatedly at Beaufort in 

 winter and spring, and specimens 24-35 '""^' caught from a school on April 23, 



