DETAILED STUDY OF CHANGES IN SHADE, COLOR, AND PATTERN IN 

 PARALICHTHYS AND ANCYLOPSETTA. 



BEHAVIOR. 



Observations were made throughout two seasons Quiy 17 to Sept. i, 1913, and 

 June 17 to Sept. 23, 1914) on flounders, especially Paralichihys and Ancylopsetta, with 

 reference to their habitat, activities, character of food, method of feeding, modifiability 

 in reactions, etc. In these observations two methods v/ere followed — direct observa- 

 tions on specimens kept in aquaria, both in the laboratory and outside, and inquiry 

 among fishennen. 



Nearly all of the specimens kept in the aquaria were taken in seines on the sandy 

 beaches of the marshes in the immediate neighborhood of the laboratory at Beaufort. 

 They varied in length from about 3 to 33 cm. Most of them were kept in large, shallow, 

 wooden aquaria containing water about 5 cm. deep. These fish are naturally very 

 hardy, and under such conditions they thrived very well with a surprisingly small 

 amount of change of water. This was especially true of the larger ones, 5 cm. long 

 and larger, practically all of which lived the entire season. For a few days after they 

 were put into the aquaria they appeared to be somewhat shy and did not feed, but 

 after that most of them fed freely and nearly all became very tame, so that they could 

 be handled without becoming noticeably excited. A number of individuals became so 

 tame that, if hungry — and they appeared to be hungry nearly all of the time — they would 

 come to the surface of the water whenever anyone came near, apparently looking for 

 food, and if offered they would take it directly from the fingers. 



In general, the specimens in the aquaria seemed to prefer living minnows or shrimp, 

 but most of thcra came to take readily dead specimens either entire or cut. They were 

 usually fed every other day, almost entirely on living menidia and dead anchovies. 



In nature and in aquaria containing soil, flounders are usually found partly 

 buried. Oftentimes only the eyes and the mouth are visible. (Fig. 5.) When they 

 are thus buried, or bedded, as it is ordinarily called, it usually requires considerable 

 stimulation to cause them to leave, and after they do leave they usually swim only a 

 short distance and then suddenly bed again. This is accomplished by a series of rapid 

 vibratory movements in different parts of the body, the fins and the tail successively, 

 of such a nature that while the animal remains stationary strong currents of water 

 are produced under it which carry the soil out in all directions. The fish then suddenly 

 comes to rest on the bottom and the soil settles down on it. If it is fine the entire 

 animal usually becomes well covered; if coarse only a portion along the edge. 



(PI. XIX, XX.) 



In aquaria without soil they give the bedding reaction quite as freely as in those 

 with soil, and they continue to give it for at least several months, but there is some 

 evidence indicating that they give it less frequently and less vigorously. This was 

 particularly noticeable in a few specimens of P. alhiguttus after they had been in a 

 wooden aquarium for four months. 

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