164 BULLETIN OF THE BUREAU OF FISHERIES 



On February 28, 1927, the first collection of larval black drum was secured in 

 Harbor Island Light Baj^ou in nearly the same spot where the first larval redfish 

 and croakers were taken some months previous. These young drum ranged from 

 4 to 6 millimeters in length and were not identified definitely as black drum {Pogonias 

 cromis) until the second week in March, after the gill nets had indicated the move- 

 ment of the spawning adults from the bays to the Gulf of Mexico. The fish were help- 

 less and obviously at the mercy of the tidal current, which had swept them into the 

 quiet bayou from the channel leading from Aransas Pass and the Gulf. (See Table 13.) 



On March 11 Corpus Christi Pass was visited and large numbers of larval and 

 post-larval drum were taken in the main channel of the pass itself, as well as along 

 the shore lines of the various islands in Laguna Madrc adjacent to the pass and 

 reached by the incoming tides. In all cases was it evident that the larval drum were 

 being brought in from the Gulf by the tidal currents. As shown in Table 13, con- 

 tinuous collections of larval and very j^oung drum were made about both Corpus 

 Christi and Aransas Passes during March and April. 



It was observed that the young drum left the vicinity of the passes as soon as able, 

 and it was believed, on the basis of the collection of small drum near Oso Bay on May 

 13, 1926, that the fish were making for definite localities, such as Oso and Nueces 

 Bays. On April 9 a considerable number of young drum had reached the channel 

 leading from Corpus Christi Bay into Oso Bay. These fish ranged in length from 

 8 to 11 millimeters (under 0.5 inch) and were the approximate size of the smallest of 

 the young drum caught in the beach pools in the same locality on May 13, 1926. 

 On the day these fish were taken, the current was running out from Oso Bay, with 

 the result that the young were forced to remain at the mouth of the channel for some 

 time. 



Nueces Bay, similar in most respects to Oso Bay but on a nearly direct line with 

 a recently completed ship channel that connects Aransas Pass with the city of 

 Corpus Christi, was fished at various points during April and May. Many young 

 drum from 9 to 15 millimeters long were taken in late April, while large numbers of 

 young, growing rapidly in size, were secured throughout the month of May. 



By the time field operations were discontinued, at the end of Ma.y, 1927, the 

 young larval drum had ceased to come into the passes from the Gulf, and those that 

 had gained entrance were concentrated largely within Nueces and Oso Bays and 

 probably Laguna Madre. The young drum preferred the same type of environment 

 as was chosen generally by the older fish. 



Several complications in the way of a thorough understanding of the spawning 

 habits of the black drum leave an interesting field for future research along this line. 

 No explanation is ofl'ered for the lack of j'oung drum that should have come from the 

 ripening fish taken from July to October, 1926. Whether they escaped observation, 

 owing to their small numbers, or whether there were no fish to be taken are questions 

 unsolved at the present time. The writer expresses the opinion, however, on the 

 basis of the relatively small size of the maturing fish taken in July to September, 1926 

 (Table 16), that spawning at this time was negligible. The main spawning season of 

 the black drum in the vicinity of Corpus Christi Bay undoubtedly is from late Feb- 

 ruary to May, and the spawning grounds probably are situated at the mouths of 

 the passes in the Gulf of Mexico. 



