REPRODUCTION AND DEVELOPMENT OF SCIAENIDAE 
43 
No key is offered for specimens more than 35 millimeters long because it is 
believed that such specimens have sufficient adult characters developed to be identi- 
fied by keys prepared from adult fish, such as appear in various taxonomic treatises. 
More complete descriptions of the eggs and young than are contained in the 
keys presented occur in the following works. For descriptions of the eggs and newly 
hatched young of Menticirrhus saxatilis see Welsh and Breder (1924). For accounts 
of the egg and larval development of Bairdiella chrysura consult Kuntz (1914) and 
Hildebrand and Cable (1930). For descriptions of young Sciaenops ocellatus and 
Pogonias crornis refer to Pearson (1929). For accounts of the development of the 
eggs and the young of Cy noscion regalis see Welsh and Breder (1923) and Pearson. 2 
And for descriptions of young Leiostomus xanthurus and Micropogon undulatus refer 
to Hildebrand and Cable (1930). Accounts of the other species included in the keys 
are contained in the present paper. 
KEY TO THE EGGS 3 
[Sciaenid eggs so far as known are pelagic and spherical in form] 
a. Eggs generally with only 1 oil globule, rarely with more than 2. 
b. Range in diameter 0.66 to 0.77 millimeter, average 0.69; yolk with only a few pigment 
spots (dark green in color) in advanced state of development, none in younger stages; 
embryo and oil globule in advanced stages with somewhat scattered dark dots. 
Bairdiella chrysura 
bb. Range in diameter probably about 0.8 to 0.92 millimeter, average 0.84; yolk profusely 
dotted (with dark green granules) in advanced state of development, some dots appearing 
during the cleavage stages; embryo and oil globule profusely spotted -Cynoscion regalis 
aa. Eggs generally with more than 1 oil globule, often with 3 or 4, sometimes with as many as 13 
to 18, reduced to 1 in advanced embryonic stages. Range in diameter 0.76 to 0.92 millimeter, 
average about 0.83. Yolk without pigment spots, the embryo with rather prominent scattered 
grayish dots Menticirrhus saxatilis 
KEY TO NEWLY HATCHED YOUNG 1 
a. Length at hatching 1.5 to 1.8 millimeters, average about 1.6; vent nearer end of snout than tip 
of tail (notochord) by a distance equal to almost twice the diameter of eye. Caudal portion 
of body with a congregation of dark green chromatophores forming a suggestion of a cross bar 
at midcaudal length Bairdiella chrysura 
aa. Length at hatching 1.75 to 2.0 millimeters, average about 1.9; vent less than an eye’s diameter 
nearer end of snout than tip of tail (notochord). Caudal portion of body with two cross bars 
composed of dark green chromatophores, one at about midcaudal length and the other one 
(less distinct) about midway between the vent and the first mentioned bar. 
Cynoscion regalis 
aaa. Length at hatching 2.0 to 2.25 millimeters; vent about an eye’s diameter nearer end of snout 
than tip of tail (notochord) ; caudal portion of body with 3 equally spaced black and golden 
bars, the first one being situated immediately behind the vent Menticirrhus saxatilis 
KEY TO SPECIMENS 1.7 TO 1.8 MILLIMETERS LONG 
a. Caudal portion of body long and slender, much longer than rest of body; distance from end of 
snout to vent about 2.75 times in length to tip of tail (without finfold); depth immediately 
behind vent notably less than diameter of eye. 
3 Unpublished manuscript in the files of the Bureau of Fisheries entitled “Seasonal Distribution and Abundance of Pelagic 
Marine Fish Eggs and Young Fishes at the entrance to Chesapeake Bay, Va.’’ 
3 The key is based on live eggs. 
• The key is based on live larvae. Keys to all other young are founded on preserved specimens. 
