182 



BULLETIN OF THE BUREAU OF FISHERIES 



39 



LENGTH- INCHES 



7.8 11.8 15.7 19.6 Zi6 ^Z5 



remote bays throughout the spring and summer indicated conchisively that the species 

 spawns within intercoastal waters. 



Throughout the period of collection no spotted trout under 10 centimeters long 

 (4 inches) were obtained from the Gulf of Mexico or from the immediate vicinity of any 

 of the passes. This is in strong contrast with the large numbers of young redfish, drum, 

 croakers, and spots spawned in the Gulf and that could be obtained either in the Gulf 



waters or about the passes. The fact that rela- 

 tively few larval and post-larval spotted trout were 

 secured by the investigator, compared with the abun- 

 dant collections of other species, can be accounted 

 for by the nature of the environment in which 

 spawning occurs. 



Since the eggs of the redfish and black drum 

 were deposited, probably within a short period of 

 time, in a limited area at the mouth of the passes, 

 natural concentration of eggs and larval fish occurred, 

 particularly when the young were carried into the 

 channels of the passes. This concentration made 

 possible large catches of the young fish around the 

 passes. The spawning season of the spotted trout, 

 on the other hand, was observed to be long, and the 

 spawning ground covered wide areas in suitable bays 

 and lagoons. Obviously, no concentration of young 

 fish could result. 



Spawning of the spotted trout probably occurs 

 somewhat offshore in the various bays, in water not 

 over 10 to 15 feet deep, although ripe and apparently 

 spawning adults may be taken during the night close 

 to shore. The eggs probably are buoyant and soon 

 drift and hatch over the grassy-bottomed, shallow 

 water, the young seeking protection in the thick 

 aquatic vegetation. The concentration of young in 

 patches of grass was noticeable. Smith (1907, p. 312) 

 stated that the spawning grounds of the spotted 

 trout in North Carolina are in the bays and sounds 

 and that the egg hatches in 40 hours in water with a 

 temperature of 77° F. 



m. 



FI5Hr 

 50 



40 



30 



20 

 10 



OH 



20 



10 



20 



10 



20 



10 



10 20 30 40 50 60 

 LeNGTH-CENTIMETERS 



70 



Fiii. 29.— Length-lrequency distribution of 

 spotted trout in Tesas, 1926-27. Actual 

 frequencies have been smoothed by a moving 

 average of tiirees 



GROWTH AND AGE 



On the basis of the frequency distribution of the total length measurements of 

 approximately 3,000 spotted trout taken by experimental and commercial collecting 

 gear from May, 1926, to June, 1927, it can be stated that, while size groups appear 

 in the frequency summaries (Table 20 and fig. 29), no one definite year class, save the 

 youngest, can be traced clearly or recognized throughout the entire period of collec- 

 tion. There is a decided tendency for the various age groups to overlap one another 

 to such a great extent^as to render any estimations of the growth and age, from length- 

 frequency studies, unreliable. The writer had noted this fact previously with respect 



