REPRODUCTION AND DEVELOPMENT OF SCIAENIDAE 
81 
advancement in pigmentation has taken place. The few dark markings usually 
present are shown in figure 24. Some specimens, however, have a series of 3 to 7 
(instead of 1) dark spots on the side below the spinous dorsal, as well as several on 
the posterior part of the head and on the nape (fig. 24). 
Specimens 18 to 20 millimeters long . — The fish has made considerable headway 
toward acquiring the form of the adult. Although the head has increased in width, 
it remains proportionately much more compressed than in the adult, its length is 
contained 2.55 to 2.75 in the total length without the caudal fin. The interorbital 
space has become relatively broad and is about 1.5 times as wide as the small eye. 
The snout is slightly longer than the eye and is contained 4.6 to 5.5 times in the head. 
The preopercular margin has 3 or 4 small spines, and 3 bony stays are partly embedded 
in the interopercle. A row of bony serrae are present at the shoulder. A slight 
concavity remains present between the vent and the anal fin, the membrane (rem- 
anent of the finfold) which occupied the concavity in smaller fish has disappeared, 
and the distance between the vent and origin of anal is now scarcely as long as the 
Figure U.—SleUifer lanceolalus. From a specimen 13 millimeters long. 
eye. The proportionate depth of the body remains the same as in fish 10 to 13 
millimeters long. Much advancement in pigmentation has taken place. The dark 
spot near the end of the base of the anal, present in all younger fish, remains evident 
and is preceded (along the base of the anal) as well as followed (on the ventral outline 
of the peduncle) by a row of dark dots and spots. The characteristic elongate, 
slightly arched spot on the opercle, immediately in advance of the upper angle of 
the gill opening, remains prominent. The mouth is margined with black and numer- 
ous dusky markings occur on the head and nape, and on the upper parts of the sides. 
The markings are variable in size and intensity among specimens. One row of spots 
follows the base of the dorsal and another one parallels it about an eye’s diameter 
lower on the side. Other scattered markings are present, and a dark bar is situated 
on the base of the caudal. 
Specimens 25 to 30 millimeters long . — Although advancement toward the adult 
form has been rather rapid since a length of 18 to 20 millimeters was attained, the 
fish remains more compressed anteriorly and the snout is more pointed. The head 
is contained 2.8 to 2.9 times in the length to the base of the caudal, and the depth 
2.7 to 3.1 times. These proportions are close to those of adult fish. The small eye 
is surrounded by a ridge which is not yet fully ossified, its longest diameter is contained 
4.5 to 5.2 in the head; snout 4.25 to 4.5 times; interorbital 2.7 to 3.2 times; maxillary 
1.8 to 1.95 times. The concavity between the vent and the anal, present in younger 
fish has disappeared, and the body in this region has thickened and no longer is 
semitransparent. Outlines of scales are present on most of the body. If scales 
