FISHES 147 



mackerels, and the common herring, all highly im- 

 portant commercial species, belong to the pelagic 

 group. Examples of the opposite extreme, namely, 

 of fishes dwelling on the bottom, are the flatfishes, 

 the croakers, the black drum, the kingfishes, and the 

 skates and rays. Many marine fishes cannot be 

 classed either as surface or bottom dwellers, for they 

 may be at the bottom or at the surface, or they may 

 occupy intermediate depths. Among this large and 

 varied group are the cod, the sea-basses, the weak- 

 fishes, the bluefish, the mullets, the spot, the butter- 

 fishes, the groupers, the grunts, the snappers, the 

 porgies, and numerous others. 



Spawning and Reproduction 



Spawning in fishes occurs at more or less definite 

 periods of the year, the season varying among the 

 species. The majority, however, spawn in the spring 

 and summer. Most of the salmons, the striped mullet, 

 the cod, the spot, some of the flounders, and the 

 menhaden are among the exceptions, as these all 

 spawn during the fall and winter. The spawning 

 period in some species is very short; in others it is 

 so protracted that it extends over several months. 



Nearly all fishes have more or less definite spawn- 

 ing grounds. The spawning grounds also are the 

 feeding grounds for the young for some time after 

 hatching. As the early larval stages, when the fish 

 first begin to feed, are probably the most critical 

 of their lives, the condition of the spawning grounds 

 is extremely important. It is readily understood that 

 if the proper food on account of weather conditions. 



