YOUNG OF SOME MARINE FISHES IN LOWER CHESAPEAKE BAY, VA. 



93 



series of small black chromatophores is present along the ventral edge of the body 

 extending from the vent to the tail. A chromatophore at midcaudal length, or at 

 the primitive base of the anal, is consistently more pronounced than the rest. Several 

 small chromatophores are found along the ventral edge of the abdomen. No other 

 color markings are evident. The yolksac has been absorbed at 1.8 mm., although 

 Welsh and Breder (1923) found a yolksac present on young of 2.2 mm. length taken 

 in Delaware Bay. 6 



The young sea trout at 3 mm. has the body depth proportionately increased. 

 The only color marking is the series of chromatophores along the ventral edge of the 



Figure 16.— Cynoscion regalia. From a specimen 1.8 mm. long. 



body. All chromatophores become more pronounced, particularly the one at mid- 

 caudal length. The fin fold remains entire. Minute teeth, usually evident at this 

 length, help to distinguish the young sea trout from some related Sciaenidae such as 

 the sand perch, Bairdiella chrysura, and the croaker, Micropogon undulaivs (fig. 17). 



Figure 17. — Cynoscion recalls. From a specimen 3 mm. long. 



The young sea trout at a length of 4.6 nun. has the caudal fin rays evident and 

 shows a slight differentiation of the anal and dorsal fin rays. The fin fold remains 

 entire. The greatest depth of the body is contained 2.7 to 3.0 times in the length to 

 the end of the notochord. The series of ventral chromatophores has largely disap- 

 peared, with the exception of the spot at the base of the anal which appears enlarged 

 and anastomosed. This anal spot is significant for it apparently distinguishes the 

 young of C. regalis from both C. nebulosus and C. nothus. Markings on the abdominal 

 cavity are also pronounced. The mouth is more oblique and the teeth further 

 developed (fig. 18). 



The young fish is quite readily identified at 8.2 mm. for the anal fin rays are usually 

 distinct, while the soft dorsal rays are almost fully differentiated. The fin fold 

 remains entire to the caudal fin. The greatest depth of the body is now contained 

 about 2.8 times in the standard length. The snout is quite blunt, the lower jaw 



• All length measurements in this paper are referable to preserved specimens and denote total length. 



