NATURAL HISTORY OF REDFISH, ETC., OF TEXAS 173 



Present knowledge of the exact causes for the voluntary response of young 

 fishes to a certain type of environment is too inadequate to permit a conjecture as 

 to the possible factors that cause the determined effort of the young drum to reach 

 definite isolated bays and lagoons wherein verj' few species of marine fish dwell. 

 The fact remains, however, that these young drum are attracted to a particular 

 type of aquatic environment soon after coming in from the Gulf of Mexico, to such 

 a degree as to render the absence of the small fish in other types of coastal waters 

 most noticeable. 



The young drum generally remain within their favorite bays until they attain 

 a length of at least 10 centimeters (4 inches), when many of them gradually move 

 out into the deeper bays and, to a slight extent, into the Gulf of Mexico. The 

 young drum (fish under 10 centimeters) are more prone than redfish to stay away 

 from the open shores of the Gulf. Most of the drum population, however, appears 

 to reside imtil matuiity (spawning time) within the shallow waters chiefly of Laguna 

 Madre and Oso and Nueces Bays, but relatively few fish roaming into the deeper 

 waters. 



The spawning migration of the adult drum from the shallow intercoastal waters 

 to the Gulf of Mexico is most pronounced in the vicinity of Oso and Nueces Bays 

 and Laguna Madre, where, from late January to May, special gill nets are employed 

 to intercept and capture the schools of migrating fish. From personal observations 

 it would seem that the greater part of this movement from the bays takes place at 

 night. The distance to be traveled from such waters as Oso or Nueces Bay to the 

 nearest pass to the Gulf of Mexico may lie, roughly, between 20 and 30 miles. Such 

 a distance might easily be covered by the drum within a few days, which perhaps 

 explains the nearly ripe condition of most drums before they leave the bays. 



After spawning outside the passes the spent adults that survive appear to come 

 closer inshore to seek their way back into the bays. Considerable numbers of these 

 spent drum were taken in the late spring of 1927 along the Gulf beaches near the 

 passes as well as immediately within some of the passes. No collections of spent 

 adults were obtained at any time within the confines of either Oso or Nueces Bay, 

 which fact in itself would indicate that spawning does not take place in these bays. 



The drimis are extremely persistent in remaining within the shallow intercoastal 

 waters, both during the excessive heat and salinity of the water in summer and the 

 sudden-killing cold waves in winter. With the shallow bays preferred by the drum 

 nearly completely isolated from the deeper ones, escape in times of danger is not 

 accomplished readil3^ Navigation within these shallow waters is difficult, and 

 many of the migrating adults have their bellies badly lacerated from the continual 

 friction in passing over oyster reefs, particularly during the excitement of breeding. 

 It has been said that in past years farmers were accustomed to chase the large 10 

 to 40 pound drum over the shallow mud flats with pitchforks, such chase, of course, 

 furnishing a considerable amount of thrill as well as fish. 



During the summer the waters in the vicinity of Baffin Bay (Laguna Madre) 

 often become extremely saline, with the result that many fish, particularly black drum, 

 die. Cold waves in winter, which chill the shallow water rapidly, are said to work 

 destruction with the species because of the inability of the fish to reach more favorable 

 environments. 



