STICKNEY, TAYLOR, and HEARD: FOOD HABITS OF FOUR FLOUNDERS 



each season of the year to provide rehability to 

 the data (Figure 4). 



The food habits of E. crossotus were similar in 

 both the rivers and sounds of Georgia. There were 

 some alterations in food habits associated with 

 increased standard length, however. While Ps. 

 coronatus was present in a greater percentage in 

 the stomachs ofE. crossotus of all sizes than any 

 other food organism, polychaetes increased in 

 importance in fishes longer than 100 mm. The 

 appearance of polychaetes in stomachs of larger 

 E. crossotus may be a function of the increase 

 in mouth size during growth. 



Virtually all of the copepods found in the 

 stomachs of E. crossotus were Ps. coronatus. 

 Plankton samples taken by us during the course 

 of this study verified that the copepod population 

 in Georgia coastal waters is dominated by 

 Ps. coronatus. 



During October 1972, a series of bihourly 

 trawls over a 24-h period was obtained in Ossa- 

 baw Sound. Each trawl was of 10-min duration 

 and covered the same bottom. A total of 121 

 E. crossotus were captured in the 12 samples, 

 and their stomachs were analyzed. Data from 

 these fish were excluded from Figure 3 but are 

 included in Figure 5. 



UJ 



0800 

 1000 



1200 

 1400 



1600 

 1800 



2000 

 2 200 



2400 



0200 

 0400 



0600 



Pseudodioptomus 

 coronatus 



Porapnonospio Neomysis r 



pinna To amer icana 



Pseudodiaptomus coronatus 



Pseudodioptomus coronatus 



Pseudodioptomus coronatus 



Pseudodiaptomus coronatus 



Leucon p r 

 amer. . ' 



Pseudodioptomus cornotus 



Pseudodioptomus coronatus 



pac^ 



Pseudodiaptomus coronatus 



Pseudodiaptomus coronotus 



Pseudodiaptomus coronotus ( 5 of 6 stomachs empty) 



N = 2 

 N = 13 



N = 8 

 N = II 



N =18 

 N = 7 



N = 17 

 N =12 



N = II 



N = 1 

 N = 6 



N = 15 



_L. 



10 20 30 40 50 60 70 80 90 100 

 CUMULATIVE PERCENTAGE 



Figure 5. — Histogram illustrating the feeding habits of 

 Etropus crossotus at 2-h intervals for 24 h. (N = number 

 of stomachs analyzed for each bar, C = Crustacea other than 

 those specifically identified in the bar, P = polychaetes, and 

 Leucon amer. . . = Leucon americanus.) 



P. coronatus was the numerically dominant 

 organism in the stomachs with the exceptions of 

 samples taken at 0200, 0600, and 0800 h. At 

 0200 and 0600 h none of the stomachs examined 

 (16) contained food. At 0800 h only two E. 

 crossotus were obtained, and a variety of food 

 organisms were identified, with Ps. coronatus 

 most abundant. The 0400 h sample contained six 

 E. crossotus of which only one contained food 

 (100% Ps. coronatus). 



Based on this limited information, it appears 

 that£. crossotus feeds mainly during the daylight 

 hours with unchanging food habits throughout 

 the day. This observation correlates with the 

 findings of de Groot (1971) which indicate that 

 bothids are visual feeders. 



Ancylopsetta quadrocellata 



The food habits of A. quadrocellata at different 

 seasons of the year, location within the estuary, 

 and standard length are presented in Figure 6. 

 The preponderance of the animals were captured 

 during the spring, reflecting the seasonal avail- 

 ability of this fish in Georgia estuarine waters. 



N. americana was the dominant food organism 

 throughout the year. Trachypenaeus constrictus 

 became important during the summer and fall. 

 Neopanope sayi was present in significant quan- 

 tities during the winter. 



While the food habits of A. quadrocellata cap- 

 tured in rivers were nearly identical to those cap- 

 tured in sounds, there were some differences in 

 food habits with size of the fish. A^^. americana 

 exceeded 50% of the total number of organisms 

 found in the stomachs of fishes of less than 150 

 mm. Fish remains were found in the stomachs of 

 fishes longer than 75 mm, although fish were 

 never the dominant food organism. T. constrictus 

 first became important as food in A. quadrocellata 

 longer than 100 mm and was the dominant or- 

 ganism in fishes from 150 to 174 mm. Fishes 

 longer than 175 mm fed on a variety of organisms. 

 These data indicate that the diversity of foods 

 increases with the size of the predator. The rela- 

 tively large mouth of A. quadrocellata compared 

 to that ofE. crossotus may account for some of 

 this variability in food habits with size (Figure 2). 



Ps. coronatus, the dominant organism in the 

 stomachs of E. crossotus, was virtually absent 

 from the stomachs of A. quadrocellata longer than 



521 



