BAIRDIELLA CHRYSURA AND ANCHOVIA MITCHILU. 



19 



During the early summer larvse of Anchovia mitchilli and Anchovia brownii were fre- 

 quently taken together. In this stage the two species are very similar and might readily 

 be confused, the larvae of the latter, however, being somewhat the longer and compara- 

 tively more slender. The vent is also located correspondingly farther posteriorly in the 

 latter than in the former. As soon as the dorsal and anal fins have become fully differen- 

 tiated, the young of either species may be recognized by the character of the anal fin. 

 The number of anal fin rays in Anchovia brownii usually does not exceed 20. In Anchovia 

 mitchilli the anal fin rays number 25 to 28. In the latter species the anal fin also is longer 

 and terminates less abruptly and nearer the base of the caudal fin than in the former. 



m^. 



\ ' " ^'^''j'[!niiinini<i!iiiinj;!,ri: 



Fig. 43. — I.ar\-al fish 7,5 mm. in length. 



Fig. 46. — Adult fish 7 cm. in length. 



ANCHOTIA MnCHILLI. 



Figure 46 illustrates an adult fish. The adult of this species does not differ markedly 

 in form and appearance from the adult of Anchovia brownii. The average length of the 

 body is somewhat greater and its relative depth is somewhat less in the latter, while 

 the silvery lateral band of A. mitchilli is narrower and less distinct than in brownii. 

 More distinctive characters are the anal fin, as indicated above, and the position of 

 the vent. In the larvae of both species the vent is located opposite the middle of the 

 dorsal fin or farther posteriorly. In the adult of Anchovia mitchilli the vent is located 

 opposite the origin of the dorsal fin, while in the adult of Anchovia brownii the vent is 

 located approximately opposite the middle of the dorsal fin. 



