FISHERY BULLETIN: VOL. 69, NO. 3 



necessarily genetically controlled. When present 

 in significant numbers, abnormalities may have 

 important implications for those considering 

 flatfishes in aquaculture. 



METHODS 



Rearing techniques were briefly described and 

 larval development through metamorphosis re- 

 ported by Houde et al. (1970). Methods used 

 to rear A. lineatus were similar to those de- 

 scribed in detail by Houde and Palko (1970). 

 The 31 juveniles of lined sole were maintained 

 in two 75-liter aquariums and fed on frozen 

 brine shrimp {Artemia salina). Before meta- 

 morphosis larvae were fed wild zooplankton 

 which consisted mostly of copepods. Beginning 

 50 days after hatching and at approximately 

 1-month intervals, growth was determined by 

 measuring fish to the nearest millimeter total 

 length (TL) and then returning them to the 

 aquariums. Individuals were recorded as nor- 

 mal or abnormal when they were measured, the 

 distinction being based on whether the dorsal 

 fin was hooked. 



Beginning 137 days after hatching, some fish 

 were sacrificed and preserved for detailed ex- 

 amination. Radiographs were made to study 

 skeletal structures. Specimens were accessioned 

 into the fish collection at the Tropical Atlantic 

 Biological Laboratory. 



NORMAL SPECIMENS 



Only five specimens were normal in all respects 

 (Figure 1). Meristics and morphometries of 

 normal individuals fell within the range of var- 

 iation for the species (Jordan and Evermann, 

 1898). 



GROWTH AND MORTALITY 



Growth was compared between grossly de- 

 formed specimens with hooked dorsal fins and 

 normal specimens or those whose only anomalies 



Figure 1. — Left side (upper photo) and right side (lower 

 photo) of 45.8 mm TL normal Achinis lineatus reared 

 in the laboratory. Dorsal fin was bent when specimen 

 was preserved but it is normal. 



consisted of unusual pigmentation and the pres- 

 ence of a left pectoral fin. SiJecimens with ab- 

 normal pigmentation or with left pectoral fins 

 were classified as "normal" at the time they 

 were measured because such conditions could 

 not always be detected in small living juveniles. 

 Although "normal" individuals initially were 

 longer than abnormal ones, some compensation 

 apparently occurred, and little diflference in 

 lengths was apparent between specimens still 

 living from the two categories at 250 days after 

 hatching. Both "normal" and abnormal speci- 

 mens averaged about 52 mm TL at this time. 

 No natural mortality occurred for either normal 

 or abnormal lined soles between 50 and 275 days 

 after hatching. 



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